Airboat - SchoolRack

Airboat
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(Redirected from Air boat)
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An air boat
Airboats are essentially flat-bottomed
vessels propelled in a forward direction by
an aircraft-type propeller and powered by
either an aircraft or automotive engine.[1]
Airboats are a very popular means of
transportation in the Florida Everglades, and
Louisiana Bayou, where they are used for
fishing, bowfishing, hunting and ecotourism.
Aft view of safety cage during operation
•
Description
The engine and propeller are enclosed in a protective metal cage that prevents objects, e.g., tree
limbs, branches, clothing, beverage containers, or wildlife, from coming in contact with the
whirling propeller, which could cause devastating damage to the vessel and traumatic injury to
the operator and passengers. The propeller produces a rearward column of air that propels the
airboat forward. Steering is accomplished by forced air passing across vertical rudders. There
must be a forceful airflow in order for the vessel to be steered. Airboats do not have brakes and
are incapable of traveling in reverse. Stopping and reversing direction are dependent upon good
operator/pilot/driver skills.
The operator/pilot/driver and in most instances the passengers, are seated in elevated seats that
allow visibility over swamp vegetation. The improved visibility permits the operator and
passengers to observe floating objects, stumps and animals in the airboat's path.
The characteristic flat-bottomed design of the airboat, in conjunction with the fact that there are
no operating parts below the waterline, permit the vessel to be easily navigated through shallow
swamps and marshes, in canals, rivers and lakes as well as on frozen lakes. The airboat's design
makes it the ideal vessel for flood and ice rescue operations.
Steering the airboat is accomplished by swiveling vertical rudders positioned at the rear (stern) of
the vessel. The propeller produces a column of air that produces forward momentum. That
column of air passes across the rudders, which are directed through the forward and backward
movement of vertical "stick" located on the operator's left side. The "stick" is attached to the
rudders via teleflex cable or linked rods. Overall steering and control is a function of water
current, wind, water depth and propeller thrust.
The sound produced by an airboat's propeller and engine can be loud; the majority of the sound
is produced by the propeller. Modern airboat designs and modern technology have significantly
reduced the sound that an airboat produces. Modern airboat engines are equipped with mufflers
and multi-blade carbon-fiber propellers that greatly reduce the sound emitted by the airboat.
Airboats vary in size from 10-foot hunt/trail boats, with a two- to three-passenger capacity, to
large 18-passenger and greater tour boats.
[edit] Public safety
The Army Corps of Engineers uses an
airboat to collect herbicide-resistant hydrilla
from Lake Seminole in northern Florida
In recent years airboats have grown in
popularity in the area of public safety.
Airboats have proven to be indispensable for
flood, shallow water and ice rescue
operations. During the flooding of New
Orleans following Hurricane Katrina,
August, 29, 2005, airboats from across the
United States rescued thousands of flood
victims. Thirty airboats evacuated over
3,000 patients and medical staff from four
downtown New Orleans hospitals in less
than 36 hours.
Numerous articles have been published in fire-rescue trade journals, i.e., Fire Engineering,
National Fire and Rescue Magazine, describing the advantages, capabilities and benefits of using
airboats for water rescue operations, and in depth descriptions of actual water rescue incidents,
including the flooding of New Orleans.[2][3][4][5][6][7]
[edit] Airboat powerplants
Airboats are powered by either an aircraft or large block automotive engine, ranging from 125 to
over 600 horsepower. Replacement parts and ease of repair make the automotive engine the
preferred powerplant. Also, high octane automotive gas is less expensive than aviation gas
required by the aircraft engines.
An automotive engine powered airboat generally has more power to push through high grass or
carry heavy loads. An aircraft engine powered airboat may still be preferred in situations where a
light boat or greater maneuverability is desired.
[edit] Safety
Knowledge of operational safety is essential when operating an airboat.
The average airboat produces a 150-mile-per-hour (241 km/h) prop wash behind it and if a tree
branch gets into a propeller the spray of material could be devastating, causing damage to the
vessel and injury to the boat's occupants.
Modern commercially manufactured airboat hulls are made of aluminum or fiberglass. The
choice of material is determined by the type of terrain in which the vessel will operated.
Airboat manufacturers tend to be small, family run businesses that assemble built to order boats;
airboats are also manufactured in Russia and Australia. Normally a truck or airplane engine is
positioned on the back of the boat with a wood or carbon fiber propeller. Importation to
European Union is difficult due to the high cost of the CE mark test, which all new and imported
used boats need from outside the EU.
[edit] History
An early form of the air boat
The first airboat, called the Ugly Duckling,
was built in 1905 in Nova Scotia, Canada by
a team lead by Dr. Alexander Graham Bell.
It was used to test various engines and prop
configurations. An associate of Dr. Bell,
Glenn Curtiss (of airplane manufacturing
fame) is reported to have registered the first
airboat in Florida, USA in 1920. It was
called the Curtis Scooter[8] and it had a
closed cockpit design.
By the 1930s homemade airboats began appearing in the swamps and marshes of Florida and
Louisiana. One company in Florida claims to have been providing airboat rides as entertainment
since the mid 1930s. Over the years a variety of designs were tried and. through trial-and-error,
the standard design used today arose: an open, flat bottom boat with an engine mounted on the
back, the driver sitting in an elevated position, and a cage to protect the propeller from objects
flying into them. One well documented case of a homemade design (though not the first) was an
airboat built by staff at the Bear River Bird Refugee near Brigham City, Utah in the 1940s. It
appears to have involved collaborative efforts by three employees of the refuge - Leo young, G.
Hortin Jensen and Cecil Williams.[citation needed]
A story in Ducks Unlimited magazine in 1987 mentioned Young and Jensen and dated the
building of the first boat in 1950. Refuge records, however, show the first boat came into use in
1943, with several photos of running air boats dated 1947. Prior to the introduction of the
airboat, refuge biologists had to either walk through shallow water and deep, sticky mud or push
unpowered flat-bottom boats with long poles. Staff had experimented with a boat called the
"Mud Queen," which had small paddle wheels on either side that pushed the boat. They build
their first airboat nicknamed "Alligator I" from a flat-bottom boat pushed along by an aircraft
engine purchased for $99.50. Young reported that he called the first airboat an "air-thrust boat."
Once word got out about the boat, Leo Young built and sold boats all over the world.
Automobile
From Wikipedia, the free encyclopedia /
Jump to: navigation, search
"Car" redirects here. For other uses, see
Car (disambiguation).
Karl Benz's "Velo" model (1894) - entered
into an early automobile race
World map of passenger cars per 1000
people.
Passenger cars in 2000
An automobile or motor car is a wheeled motor vehicle for transporting passengers, which also
carries its own engine or motor. Most definitions of the term specify that automobiles are
designed to run primarily on roads, to have seating for one to eight people, to typically have four
wheels, and to be constructed principally for the transport of people rather than goods.[1]
However, the term automobile is far from precise, because there are many types of vehicles that
do similar tasks.
As of 2002, there were 590 million passenger cars worldwide (roughly one car per eleven
people).[citation needed][2]
Etymology
The word automobile comes, via the French automobile, from the Ancient Greek word αὐτός
(autós, "self") and the Latin mobilis ("movable"); meaning a vehicle that moves itself, rather than
being pulled or pushed by a separate animal or another vehicle. The alternative name car is
believed to originate from the Latin word carrus or carrum ("wheeled vehicle"), or the Middle
English word carre ("cart") (from Old North French), or karros (a Gallic wagon).[3][4]
History
Main article: History of the automobile
Although Nicolas-Joseph Cugnot is often credited with building the first self-propelled
mechanical vehicle or automobile in about 1769 by adapting an existing horse-drawn vehicle,
this claim is disputed by some, who doubt Cugnot's three-wheeler ever ran or was stable. Others
claim Ferdinand Verbiest, a member of a Jesuit mission in China, built the first steam-powered
vehicle around 1672 which was of small scale and designed as a toy for the Chinese Emperor
that was unable to carry a driver or a passenger, but quite possibly, was the first working steampowered vehicle ('auto-mobile').[5][6] What is not in doubt is that Richard Trevithick built and
demonstrated his Puffing Devil road locomotive in 1801, believed by many to be the first
demonstration of a steam-powered road vehicle although it was unable to maintain sufficient
steam pressure for long periods, and would have been of little practical use.
In Russia, in the 1780s, Ivan Kulibin developed a human-pedalled, three-wheeled carriage with
modern features such as a flywheel, brake, gear box, and bearings; however, it was not
developed further.[7]
François Isaac de Rivaz, a Swiss inventor, designed the first internal combustion engine, in 1806,
which was fueled by a mixture of hydrogen and oxygen and used it to develop the world's first
vehicle, albeit rudimentary, to be powered by such an engine. The design was not very
successful, as was the case with others such as Samuel Brown, Samuel Morey, and Etienne
Lenoir with his hippomobile, who each produced vehicles (usually adapted carriages or carts)
powered by clumsy internal combustion engines.[8]
In November 1881 French inventor Gustave Trouvé demonstrated a working three-wheeled
automobile that was powered by electricity. This was at the International Exhibition of
Electricity in Paris.[9]
Although several other German engineers (including Gottlieb Daimler, Wilhelm Maybach, and
Siegfried Marcus) were working on the problem at about the same time, Karl Benz generally is
acknowledged as the inventor of the modern automobile.[8]
An automobile powered by his own four-stroke cycle gasoline engine was built in Mannheim,
Germany by Karl Benz in 1885 and granted a patent in January of the following year under the
auspices of his major company, Benz & Cie., which was founded in 1883. It was an integral
design, without the adaptation of other existing components and including several new
technological elements to create a new concept. This is what made it worthy of a patent. He
began to sell his production vehicles in 1888.
Karl Benz
A photograph of the original Benz Patent Motorwagen, first built in 1885 and awarded the patent
for the concept
In 1879 Benz was granted a patent for his first engine, which had been designed in 1878. Many
of his other inventions made the use of the internal combustion engine feasible for powering a
vehicle.
His first Motorwagen was built in 1885 and he was awarded the patent for its invention as of his
application on January 29, 1886. Benz began promotion of the vehicle on July 3, 1886 and
approximately 25 Benz vehicles were sold between 1888 and 1893, when his first four-wheeler
was introduced along with a model intended for affordability. They also were powered with fourstroke engines of his own design. Emile Roger of France, already producing Benz engines under
license, now added the Benz automobile to his line of products. Because France was more open
to the early automobiles, initially more were built and sold in France through Roger than Benz
sold in Germany.
In 1896, Benz designed and patented the first internal-combustion flat engine, called a
boxermotor in German. During the last years of the nineteenth century, Benz was the largest
automobile company in the world with 572 units produced in 1899 and because of its size, Benz
& Cie., became a joint-stock company.
Daimler and Maybach founded Daimler Motoren Gesellschaft (Daimler Motor Company, DMG)
in Cannstatt in 1890 and under the brand name, Daimler, sold their first automobile in 1892,
which was a horse-drawn stagecoach built by another manufacturer, that they retrofitted with an
engine of their design. By 1895 about 30 vehicles had been built by Daimler and Maybach, either
at the Daimler works or in the Hotel Hermann, where they set up shop after falling out with their
backers. Benz and the Maybach and Daimler team seem to have been unaware of each other's
early work. They never worked together because by the time of the merger of the two companies,
Daimler and Maybach were no longer part of DMG.
Daimler died in 1900 and later that year, Maybach designed an engine named DaimlerMercedes, that was placed in a specially-ordered model built to specifications set by Emil
Jellinek. This was a production of a small number of vehicles for Jellinek to race and market in
his country. Two years later, in 1902, a new model DMG automobile was produced and the
model was named Mercedes after the Maybach engine which generated 35 hp. Maybach quit
DMG shortly thereafter and opened a business of his own. Rights to the Daimler brand name
were sold to other manufacturers.
Karl Benz proposed co-operation between DMG and Benz & Cie. when economic conditions
began to deteriorate in Germany following the First World War, but the directors of DMG
refused to consider it initially. Negotiations between the two companies resumed several years
later when these conditions worsened and, in 1924 they signed an Agreement of Mutual Interest,
valid until the year 2000. Both enterprises standardized design, production, purchasing, and sales
and they advertised or marketed their automobile models jointly—although keeping their
respective brands.
On June 28, 1926, Benz & Cie. and DMG finally merged as the Daimler-Benz company,
baptizing all of its automobiles Mercedes Benz as a brand honoring the most important model of
the DMG automobiles, the Maybach design later referred to as the 1902 Mercedes-35hp, along
with the Benz name. Karl Benz remained a member of the board of directors of Daimler-Benz
until his death in 1929 and at times, his two sons participated in the management of the company
as well.
In 1890, Emile Levassor and Armand Peugeot of France began producing vehicles with Daimler
engines and so laid the foundation of the automobile industry in France.
The first design for an American automobile with a gasoline internal combustion engine was
drawn in 1877 by George Selden of Rochester, New York, who applied for a patent for an
automobile in 1879, but the patent application expired because the vehicle was never built and
proved to work (a requirement for a patent). After a delay of sixteen years and a series of
attachments to his application, on November 5, 1895, Selden was granted a United States patent
(U.S. Patent 549,160 ) for a two-stroke automobile engine, which hindered, more than
encouraged, development of automobiles in the United States. His patent was challenged by
Henry Ford and others, and overturned in 1911.
In Britain there had been several attempts to build steam cars with varying degrees of success
with Thomas Rickett even attempting a production run in 1860.[10] Santler from Malvern is
recognized by the Veteran Car Club of Great Britain as having made the first petrol-powered car
in the country in 1894[11] followed by Frederick William Lanchester in 1895 but these were both
one-offs.[11] The first production vehicles in Great Britain came from the Daimler Motor
Company, a company founded by Harry J. Lawson in 1896 after purchasing the right to use the
name of the engines. Lawson's company made its first automobiles in 1897 and they bore the
name Daimler.[11]
In 1892, German engineer Rudolf Diesel was granted a patent for a "New Rational Combustion
Engine". In 1897 he built the first Diesel Engine.[8] Steam-, electric-, and gasoline-powered
vehicles competed for decades, with gasoline internal combustion engines achieving dominance
in the 1910s.
Although various pistonless rotary engine designs have attempted to compete with the
conventional piston and crankshaft design, only Mazda's version of the Wankel engine has had
more than very limited success.
Production
Ransom E. Olds.
Portrait of Henry Ford (ca. 1919)
The large-scale, production-line manufacturing of affordable automobiles was debuted by
Ransom Olds at his Oldsmobile factory in 1902. This concept was greatly expanded by Henry
Ford, beginning in 1914.
As a result, Ford's cars came off the line in fifteen minute intervals, much faster than previous
methods, increasing production by seven to one (requiring 12.5 man-hours before, 1 hour 33
minutes after), while using less manpower.[12] It was so successful, paint became a bottleneck.
Only Japan black would dry fast enough, forcing the company to drop the variety of colors
available before 1914, until fast-drying Duco lacquer was developed in 1926. This is the source
of Ford's apocryphal remark, "any color as long as it's black".[12] In 1914, an assembly line
worker could buy a Model T with four months' pay.[12]
Ford's complex safety procedures—especially assigning each worker to a specific location
instead of allowing them to roam about—dramatically reduced the rate of injury. The
combination of high wages and high efficiency is called "Fordism," and was copied by most
major industries. The efficiency gains from the assembly line also coincided with the economic
rise of the United States. The assembly line forced workers to work at a certain pace with very
repetitive motions which led to more output per worker while other countries were using less
productive methods.
In the automotive industry, its success was dominating, and quickly spread worldwide seeing the
founding of Ford France and Ford Britain in 1911, Ford Denmark 1923, Ford Germany 1925; in
1921, Citroen was the first native European manufacturer to adopt the production method. Soon,
companies had to have assembly lines, or risk going broke; by 1930, 250 companies which did
not, had disappeared.[12]
Development of automotive technology was rapid, due in part to the hundreds of small
manufacturers competing to gain the world's attention. Key developments included electric
ignition and the electric self-starter (both by Charles Kettering, for the Cadillac Motor Company
in 1910-1911), independent suspension, and four-wheel brakes.
Since the 1920s, nearly all cars have been
mass-produced to meet market needs, so
marketing plans often have heavily
influenced automobile design. It was Alfred
P. Sloan who established the idea of
different makes of cars produced by one
company, so buyers could "move up" as
their fortunes improved.
Ford Model T, 1927, regarded as the first
affordable American automobile
Reflecting the rapid pace of change, makes shared parts with one another so larger production
volume resulted in lower costs for each price range. For example, in the 1930s, LaSalles, sold by
Cadillac, used cheaper mechanical parts made by Oldsmobile; in the 1950s, Chevrolet shared
hood, doors, roof, and windows with Pontiac; by the 1990s, corporate drivetrains and shared
platforms (with interchangeable brakes, suspension, and other parts) were common. Even so,
only major makers could afford high costs, and even companies with decades of production, such
as Apperson, Cole, Dorris, Haynes, or Premier, could not manage: of some two hundred
American car makers in existence in 1920, only 43 survived in 1930, and with the Great
Depression, by 1940, only 17 of those were left.[12]
In Europe much the same would happen. Morris set up its production line at Cowley in 1924,
and soon outsold Ford, while beginning in 1923 to follow Ford's practise of vertical integration,
buying Hotchkiss (engines), Wrigley (gearboxes), and Osberton (radiators), for instance, as well
as competitors, such as Wolseley: in 1925, Morris had 41% of total British car production. Most
British small-car assemblers, from Abbey to Xtra had gone under. Citroen did the same in
France, coming to cars in 1919; between them and other cheap cars in reply such as Renault's
10CV and Peugeot's 5CV, they produced 550,000 cars in 1925, and Mors, Hurtu, and others
could not compete.[12] Germany's first mass-manufactured car, the Opel 4PS Laubfrosch (Tree
Frog), came off the line at Russelsheim in 1924, soon making Opel the top car builder in
Germany, with 37.5% of the market.[12]
See also: Automotive industry
Fuel and propulsion technologies
Auto rickshaws in New Delhi run on
Compressed Natural Gas
See also: Alternative fuel vehicle
Most automobiles in use today are propelled
by gasoline (also known as petrol) or diesel
internal combustion engines, which are
known to cause air pollution and are also
blamed for contributing to climate change
and global warming.[13] Increasing costs of
oil-based fuels, tightening environmental
laws and restrictions on greenhouse gas
emissions are propelling work on alternative
power systems for automobiles. Efforts to
improve or replace existing technologies
include the development of hybrid vehicles,
and electric and hydrogen vehicles which do
no release pollution into the air
Petroleum fuels
Main article: Petroleum fuel engine
Diesel
Main article: Diesel engine
Diesel-engined cars have long been popular in Europe with the first models being introduced in
the 1930s by Mercedes Benz and Citroen. The main benefit of diesel engines is a 50% fuel burn
efficiency compared with 27%[14] in the best gasoline engines. A down-side of the Diesel engine
is that better filters are required to reduce the presence in the exhaust gases of fine soot
particulates called diesel particulate matter. Manufacturers are now starting to fit[when?] diesel
particulate filters filters to remove the soot. Many diesel-powered cars can run with little or no
modifications on 100% biodiesel and combinations of other organic oils.
Gasoline
Main article: Petrol engine
2007 Mark II (BMW) Mini Cooper
Gasoline engines have the advantage over
diesel in being lighter and able to work at
higher rotational speeds and they are the
usual choice for fitting in high-performance
sports cars. Continuous development of
gasoline engines for over a hundred years
has produced improvements in efficiency
and reduced pollution. The carburetor was
used on nearly all road car engines until the
1980s but it was long realised better control
of the fuel/air mixture could be achieved
with fuel injection. Indirect fuel injection
was first used in aircraft engines from 1909,
in racing car engines from the 1930s, and
road cars from the late 1950s.[14] Gasoline
Direct Injection (GDI) is now starting to
appear in production vehicles such as the
2007 (Mark II) BMW Mini. Exhaust gases
are also cleaned up by fitting a catalytic
converter into the exhaust system. Clean air
legislation in many of the car industries most
important markets has made both catalysts
and fuel injection virtually universal fittings.
Most modern gasoline engines also are
capable of running with up to 15% ethanol
mixed into the gasoline - older vehicles may
have seals and hoses that can be harmed by
ethanol. With a small amount of redesign,
gasoline-powered vehicles can run on
ethanol concentrations as high as 85%.
100% ethanol is used in some parts of the
world (such as Brazil), but vehicles must be
started on pure gasoline and switched over
to ethanol once the engine is running. Most
gasoline engined cars can also run on LPG
with the addition of an LPG tank for fuel
storage and carburettor modifications to add
an LPG mixer. LPG produces fewer toxic
emissions and is a popular fuel for fork-lift
trucks that have to operate inside buildings.
The hydrogen powered FCHV (Fuel Cell
Hybrid Vehicle) was developed by Toyota
in 2005
Biofuels
Main articles: Biofuel, Ethanol fuel, and biogasoline
Ethanol, other alcohol fuels (biobutanol) and biogasoline have widespread use an automotive
fuel. Most alcohols have less energy per liter than gasoline and are usually blended with
gasoline. Alcohols are used for a variety of reasons - to increase octane, to improve emissions,
and as an alternative to petroleum based fuel, since they can be made from agricultural crops.
Brazil's ethanol program provides about 20% of the nation's automotive fuel needs, as a result of
the mandatory use of E25 blend of gasoline throughout the country, 3 million cars that operate
on pure ethanol, and 6 million dual or flexible-fuel vehicles sold since 2003.[15] that run on any
mix of ethanol and gasoline. The commercial success of "flex" vehicles, as they are popularly
known, have allowed sugarcane based ethanol fuel to achieve a 50% market share of the gasoline
market by April 2008.[16][17][18]
Electric
Main articles: Battery electric vehicle,
Hybrid vehicle, and Plug-in hybrid
The Henney Kilowatt, the first modern
(transistor-controlled) electric car.
Tata/MDI OneCAT Air Car
2007 Tesla electric powered Roadster
A CNG powered high-floor Neoplan
AN440A, run on Compressed Natural Gas
The first electric cars were built around 1832, well before internal combustion powered cars
appeared.[19] For a period of time electrics were considered superior due to the silent nature of
electric motors compared to the very loud noise of the gasoline engine. This advantage was
removed with Hiram Percy Maxim's invention of the muffler in 1897. Thereafter internal
combustion powered cars had two critical advantages: 1) long range and 2) high specific energy
(far lower weight of petrol fuel versus weight of batteries). The building of battery electric
vehicles that could rival internal combustion models had to wait for the introduction of modern
semiconductor controls and improved batteries. Because they can deliver a high torque at low
revolutions electric cars do not require such a complex drive train and transmission as internal
combustion powered cars. Some post-2000 electric car designs such as the Venturi Fétish are
able to accelerate from 0-60 mph (96 km/h) in 4.0 seconds with a top speed around 130 mph
(210 km/h). Others have a range of 250 miles (400 km) on the United States Environmental
Protection Agency‎ (EPA) highway cycle requiring 3-1/2 hours to completely charge.[20]
Equivalent fuel efficiency to internal combustion is not well defined but some press reports give
it at around 135 miles per US gallon (1.74 L/100 km; 162 mpg-imp).
Steam
Main article: steam car
Steam power, usually using an oil- or gas-heated boiler, was also in use until the 1930s but had
the major disadvantage of being unable to power the car until boiler pressure was available
(although the newer models could achieve this in well under a minute). It has the advantage of
being able to produce very low emissions as the combustion process can be carefully controlled.
Its disadvantages include poor heat efficiency and extensive requirements for electric
auxiliaries.[21]
Air
Main article: Compressed-air car
A compressed air car is an alternative fuel car that uses a motor powered by compressed air. The
car can be powered solely by air, or by air combined (as in a hybrid electric vehicle) with
gasoline/diesel/ethanol or electric plant and regenerative braking. Instead of mixing fuel with air
and burning it to drive pistons with hot expanding gases; compressed air cars use the expansion
of compressed air to drive their pistons. Several prototypes are available already and scheduled
for worldwide sale by the end of 2008. Companies releasing this type of car include Tata Motors
and Motor Development International (MDI).
Gas turbine
In the 1950s there was a brief interest in using gas turbine engines and several makers including
Rover and Chrysler produced prototypes. In spite of the power units being very compact, high
fuel consumption, severe delay in throttle response, and lack of engine braking meant no cars
reached production.
Rotary (Wankel) engines
Rotary Wankel engines were introduced into road cars by NSU with the Ro 80 and later were
seen in the Citroën GS Birotor and several Mazda models. In spite of their impressive
smoothness, poor reliability and fuel economy led to them largely disappearing. Mazda,
beginning with the R100 then RX-2, has continued research on these engines, overcoming most
of the earlier problems with the RX-7 and RX-8.
Rocket and jet cars
A rocket car holds the record in drag racing. However, the fastest of those cars are used to set the
Land Speed Record, and are propelled by propulsive jets emitted from rocket, turbojet, or more
recently and most successfully turbofan engines. The ThrustSSC car using two Rolls-Royce
Spey turbofans with reheat was able to exceed the speed of sound at ground level in 1997.
Fixed-wing aircraft
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"Airplane" and "Aeroplane" redirect here. For other uses, see Airplane (disambiguation).
Fixed-wing aircraft
Singapore Airlines Airbus A380, a modern passenger airliner
Part of a series on
Categories of Aircraft
A fixed-wing aircraft is a heavier-than-air craft whose lift is generated not by wing motion
relative to the aircraft, but by forward motion through the air. The term is used to distinguish
from rotary-wing aircraft or ornithopters, where the movement of the wing surfaces relative to
the aircraft generates lift. In the United States and Canada, the term airplane is used; in the rest
of the English-speaking countries (including Ireland and Commonwealth nations), the term
aeroplane is more common. These terms refer to any fixed wing aircraft powered by propellers
or jet engines. The word derives from the Greek αέρας (aéras-) ("air") and -plane.[1] The spelling
"aeroplane" is the older of the two, dating back to the mid-late 19th century.[2] Some fixed-wing
aircraft may be remotely or robot controlled.
[edit] Overview
Fixed-wing aircraft range from small training and recreational aircraft to wide-body aircraft and
military cargo aircraft. The word also embraces aircraft with folding or removable wings that are
intended to fold when on the ground. This is usually to ease storage or facilitate transport on, for
example, a vehicle trailer or the powered lift connecting the hangar deck of an aircraft carrier to
its flight deck. It also embraces aircraft with "variable-sweep wings", such as the General
Dynamics F-111, Grumman F-14 Tomcat and the Panavia Tornado, which can vary the sweep
angle of their wings during flight. There are also rare examples of aircraft which can vary the
angle of incidence of their wings in flight, such the F-8 Crusader, which are also considered to be
"fixed-wing".
A Cessna 177 propeller-driven general
aviation aircraft
The two necessities for fixed-wing aircraft
are air flow over the wings for lifting of the
aircraft, and an area for landing. The
majority of aircraft, however, also need an
airport with the infrastructure to receive
maintenance, restocking, refueling and for
the loading and unloading of crew, cargo
and passengers. Some aircraft are capable of
take off and landing on ice, aircraft carriers,
snow, or calm water.
The aircraft is the second fastest method of transport, after the rocket. Commercial jet aircraft
can reach up to 1000 km/h. Certified single-engined, piston-driven aircraft are capable of
reaching up to 435 km/h, while Experimental (modified WW II fighters) piston singles reach
over 815 km/h at the Reno Air Races. Supersonic aircraft (military, research and a few private
aircraft) can reach speeds faster than sound. The speed record for a plane powered by an airbreathing engine is held by the experimental NASA X-43, which reached nearly ten times the
speed of sound.
The biggest aircraft built is the Antonov An-225, while the fastest still in production is the
Mikoyan MiG-31. The biggest supersonic jet ever produced is the Tupolev Tu-160.
[edit] Structure
An F-16 Fighting Falcon, an American
military fixed-wing aircraft
The P-38 Lightning, a twin-engine fixedwing aircraft with a twin-boom
configuration.
The Mexican unmanned aerial vehicle S4
Ehécatl at take-off
The structure of a fixed-wing aircraft consists of the following major parts:
•
A long narrow often cylindrical form, called a fuselage, usually with tapered or rounded
ends to make its shape aerodynamically smooth. The fuselage carries the human flight
crew if the aircraft is piloted, the passengers if the aircraft is a passenger aircraft, other
cargo or payload, and engines and/or fuel if the aircraft is so equipped. The pilots operate
the aircraft from a cockpit located at the front or top of the fuselage and equipped with
windows, controls, and instruments. Passengers and cargo occupy the remaining
available space in the fuselage. Some aircraft may have two fuselages, or additional pods
or booms.
•
A wing (or wings in a multiplane) with an airfoil cross-section shape, used to generate
aerodynamic lifting force to support the aircraft in flight by deflecting air downward as
the aircraft moves forward. The wing halves are typically symmetrical about the plane of
symmetry (for symmetrical aircraft). The wing also stabilizes the aircraft about its roll
axis and the ailerons control rotation about that axis.
•
At least one control surface (or surfaces) mounted vertically usually above the rear of the
fuselage, called a vertical stabilizer. The vertical stabilizer is used to stabilize the aircraft
about its yaw axis (the axis in which the aircraft turns from side to side) and to control its
rotation along that axis. Some aircraft have multiple vertical stabilizers.
•
At least one horizontal surface at the front or back of the fuselage used to stabilize the
aircraft about its pitch axis (the axis around which the aircraft tilts upward or downward).
The horizontal stabilizer (also known as tailplane) is usually mounted near the rear of the
fuselage, or at the top of the vertical stabilizer, or sometimes a canard is mounted near the
front of the fuselage for the same purpose.
•
On powered aircraft, one or more aircraft engines are propulsion units that provide thrust
to push the aircraft forward through the air. The engine is optional in the case of gliders
that are not motor gliders. The most common propulsion units are propellers, powered by
reciprocating or turbine engines, and jet engines, which provide thrust directly from the
engine and usually also from a large fan mounted within the engine. When the number of
engines is even, they are distributed symmetrically about the roll axis of the aircraft,
which lies along the plane of symmetry (for symmetrical aircraft); when the number is
odd, the odd engine is usually mounted along the centerline of the fuselage.
•
Landing gear, a set of wheels, skids, or floats that support the aircraft while it is on the
surface.
Some varieties of aircraft, such as flying wing aircraft, may lack a discernible fuselage structure
and horizontal or vertical stabilizers.
[edit] Controls
Main article: Aircraft flight control systems
A number of controls allow pilots to direct aircraft in the air. The controls found in a typical
fixed-wing aircraft are as follows:
•
A yoke or joystick, which controls rotation of the aircraft about the pitch and roll axes. A
yoke resembles a kind of steering wheel, and a control stick is just a simple rod with a
handgrip. The pilot can pitch the aircraft downward by pushing on the yoke or stick, and
pitch the aircraft upward by pulling on it. Rolling the aircraft is accomplished by turning
the yoke in the direction of the desired roll, or by tilting the control stick in that direction.
Pitch changes are used to adjust the altitude and speed of the aircraft; roll changes are
used to make the aircraft turn. Control sticks and yokes are usually positioned between
the pilot's legs; however, a sidestick is a type of control stick that is positioned on either
side of the pilot (usually the left side for the pilot in the left seat, and vice versa, if there
are two pilot seats).
•
Rudder pedals, which control rotation of the aircraft about the yaw axis. There are two
pedals that pivot so that when one is pressed forward the other moves backward, and vice
versa. The pilot presses on the right rudder pedal to make the aircraft yaw to the right,
and on the left pedal to make it yaw to the left. The rudder is used mainly to balance the
aircraft in turns, or to compensate for winds or other effects that tend to turn the aircraft
about the yaw axis.
•
A throttle, which adjusts the thrust produced by the aircraft's engines. The pilot uses the
throttle to increase or decrease the speed of the aircraft, and to adjust the aircraft's altitude
(higher speeds cause the aircraft to climb, lower speeds cause it to descend). In some
aircraft the throttle is a single lever that controls thrust; in others, adjusting the throttle
means adjusting a number of different engine controls simultaneously. Aircraft with
multiple engines usually have individual throttle controls for each engine.
•
Brakes, used to slow and stop the aircraft on the ground, and sometimes for turns on the
ground.
Other possible controls include:
•
Flap levers, which are used to control the position of flaps on the wings.
•
Spoiler levers, which are used to control the position of spoilers on the wings, and to arm
their automatic deployment in aircraft designed to deploy them upon landing.
•
Trim controls, which usually take the form of knobs or wheels and are used to adjust
pitch, roll, or yaw trim.
•
A tiller, a small wheel or lever used to steer the aircraft on the ground (in conjunction
with or instead of the rudder pedals).
•
A parking brake, used to prevent the aircraft from rolling when it is parked on the
ground.
The controls may allow full or partial automation of flight, such as an autopilot, a wing leveler,
or a flight management system. Pilots adjust these controls to select a specific attitude or mode
of flight, and then the associated automation maintains that attitude or mode until the pilot
disables the automation or changes the settings. In general, the larger and/or more complex the
aircraft, the greater the amount of automation available to pilots.
[edit] Control duplication
On an aircraft with a pilot and copilot, or instructor and trainee, the aircraft is made capable of
control without the crew changing seats. The most common arrangement is two complete sets of
controls, one for each of two pilots sitting side by side, but in some aircraft (military fighter
aircraft, some taildraggers and aerobatic aircraft) the dual sets of controls are arranged one in
front of the other. A few of the less important controls may not be present in both positions, and
one position is usually intended for the pilot in command (e.g., the left "captain's seat" in jet
airliners). Some small aircraft use controls that can be moved from one position to another, such
as a single yoke that can be swung into position in front of either the left-seat pilot or the rightseat pilot (i.e. Beechcraft Bonanza).
Aircraft that require more than one pilot usually have controls intended to suit each pilot
position, but still with sufficient duplication so that all pilots can fly the aircraft alone in an
emergency. For example, in jet airliners, the controls on the left (captain's) side include both the
basic controls and those normally manipulated by the pilot in command, such as the tiller,
whereas those of the right (first officer's) side include the basic controls again and those normally
manipulated by the copilot, such as flap levers. The unduplicated controls that are required for
flight are positioned so that they can be reached by either pilot, but they are often designed to be
more convenient to the pilot who manipulates them under normal condition.
[edit] Aircraft instruments
Instruments provide information to the pilot. Flight instruments provide information about the
aircraft's speed, direction, altitude, and orientation. Powerplant instruments provide information
about the the status of the aircraft's engines and APU. Systems instruments provide information
about the aircraft's other systems, such as fuel delivery, electrical, and pressurization. Navigation
and communication instruments include all the aircraft's radios. Instruments may operate
mechanically or electrically, requiring 12VDC, 24VDC, or 400 Hz power systems.[3] An aircraft
that uses computerized CRT or LCD displays almost exclusively is said to have a glass cockpit.
Basic instruments include:
•
•
An airspeed indicator, which indicates the speed at which the aircraft is moving through
the surrounding air.
An altimeter, which indicates the altitude of the aircraft above mean sea level.
•
A Heading indicator, (sometimes referred to as a "directional gyro (DG)") which
indicates the magnetic compass heading that the aircraft's fuselage is pointing towards.
The actual direction the airplane is flying towards is affected by the wind conditions.
•
An attitude indicator, sometimes called an artificial horizon, which indicates the exact
orientation of the aircraft about its pitch and roll axes.
Other instruments might include:
•
•
•
•
•
•
A Turn coordinator, which helps the pilot maintain the aircraft in a coordinated attitude
while turning.
A rate-of-climb indicator, which shows the rate at which the aircraft is climbing or
descending
A horizontal situation indicator, shows the position and movement of the aircraft as seen
from above with respect to the ground, including course/heading and other information.
Instruments showing the status of each engine in the aircraft (operating speed, thrust,
temperature, and other variables).
Combined display systems such as primary flight displays or navigation displays.
Information displays such as on-board weather radar displays.
[edit] Propulsion
Main article: Aircraft engine
Fixed-wing aircraft can be sub-divided according to the means of propulsion they use.
[edit] Unpowered aircraft
Main article: Unpowered aircraft
Aircraft that primarily intended for unpowered flight include gliders (sometimes called
sailplanes), hang gliders and paragliders. These are mainly used for recreation. After launch, the
energy for sustained gliding flight is obtained through the skilful exploitation of rising air in the
atmosphere. Gliders that are used for the sport of gliding have high aerodynamic efficiency. The
highest lift-to-drag ratio is 70:1, though 50:1 is more common. Glider flights of thousands of
kilometers at average speeds over 200 km/h have been achieved. The glider is most commonly
launched by a tow-plane or by a winch. Some gliders, called motor gliders, are equipped with
engines (often retractable) and some are capable of self-launching. The most numerous
unpowered aircraft are hang gliders and paragliders. These are foot-launched and are generally
slower, less massive, and less expensive than sailplanes. Hang gliders most often have flexible
wings which are given shape by a frame, though some have rigid wings. This is in contrast to
paragliders which have no frames in their wings. Military gliders have been used in war to
deliver assault troops, and specialized gliders have been used in atmospheric and aerodynamic
research. Experimental aircraft and winged spacecraft have also made unpowered landings.
[edit] Propeller aircraft
Aquila AT01
engines that turns a propeller to create
thrust. They are quieter than jet aircraft, but
they fly at lower speeds, and have lower
load capacity compared to similar sized jet
powered aircraft. However, they are
significantly cheaper and much more
economical than jets, and are generally the
best option for people who need to transport
a few passengers and/or small amounts of
cargo. They are also the aircraft of choice
for pilots who wish to own an aircraft.
Smaller and older propeller aircraft make
use of reciprocating internal combustion
Turboprop aircraft are a halfway point between propeller and jet: they use a turbine engine
similar to a jet to turn propellers. These aircraft are popular with commuter and regional airlines,
as they tend to be more economical on shorter journeys.
[edit] Jet aircraft
Jet aircraft make use of turbines for the creation of thrust. These engines are much more
powerful than a reciprocating engine. As a consequence, they have greater weight capacity and
fly faster than propeller driven aircraft. One drawback, however, is that they are noisy; this
makes jet aircraft a source of noise pollution. However, turbofan jet engines are quieter, and they
have seen widespread usage partly for that reason.
The jet aircraft was developed in Germany in 1931. The first jet was the Heinkel He 178, which
was tested at Germany's Marienehe Airfield in 1939. In 1943 the Messerschmitt Me 262, the first
jet fighter aircraft, went into service in the German Luftwaffe. In the early 1950s, only a few
years after the first jet was produced in large numbers, the De Havilland Comet became the
world's first jet airliner. However, the early Comets were beset by structural problems discovered
after numerous pressurization and depressurization cycles, leading to extensive redesigns.
Most wide-body aircraft can carry hundreds of passengers and several tons of cargo, and are able
to travel for distances up to 17,000 km. Aircraft in this category are the Boeing 747, Boeing 767,
Boeing 777, the upcoming Boeing 787, Airbus A300/A310, Airbus A330, Airbus A340, Airbus
A380, Lockheed L-1011 TriStar, McDonnell Douglas DC-10, McDonnell Douglas MD-11,
Ilyushin Il-86, and Ilyushin Il-96.
Jet aircraft possess high cruising speeds (700 to 900 km/h, or 400 to 550 mph) and high speeds
for take-off and landing (150 to 250 km/h). Due to the speed needed for takeoff and landing, jet
aircraft make use of flaps and leading edge devices for the control of lift and speed, as well as
thrust reversers to direct the airflow forward, slowing down the aircraft upon landing.
[edit] Supersonic jet aircraft
Supersonic aircraft, such as military fighters and bombers, Concorde, and others, make use of
special turbines (often utilizing afterburners), that generate the huge amounts of power for flight
faster than the speed of the sound. Flight at supersonic speed creates more noise than flight at
subsonic speeds, due to the phenomenon of sonic booms. This limits supersonic flights to areas
of low population density or open ocean. When approaching an area of heavier population
density, supersonic aircraft are obliged to fly at subsonic speed.
Due to the high costs, limited areas of use and low demand there are no longer any supersonic
aircraft in use by any major airline. The last Concorde flight was on 26 November 2003.
[edit] Unmanned Aircraft
Main article: Unmanned aerial vehicle
An aircraft is said to be 'unmanned' when there is no person in the cockpit of the plane. The
aircraft is controlled only by remote controls or other electronic devices.
[edit] Rocket-powered aircraft
Bell X-1A in flight
Main article: Rocket-powered
aircraft
Experimental rocket powered aircraft were
developed by the Germans as early as World
War II (see Me 163 Komet), and about 29
[edit] Ramjet aircraft
USAF Lockheed SR-71 Blackbird trainer
were manufactured and deployed. The first
fixed wing aircraft to break the sound barrier
in level flight was a rocket plane- the Bell
X-1. The later North American X-15 was
another important rocket plane that broke
many speed and altitude records and laid
much of the groundwork for later aircraft
and spacecraft design. Rocket aircraft are
not in common usage today, although
rocket-assisted takeoffs are used for some
military aircraft. SpaceShipOne is the most
famous current rocket aircraft, being the
testbed for developing a commercial suborbital passenger service; another rocket
plane is the XCOR EZ-Rocket; and there is
of course the Space Shuttle.
small and simple engine for high speed use,
such as missiles. The D-21 Tagboard was an
unmanned Mach 3+ reconnaissance drone
that was put into production in 1969 for
spying, but due to the development of better
spy satellites, it was cancelled in 1971. The
SR-71's Pratt & Whitney J58 engines ran
80% as ramjets at high speeds (Mach 3.2).
The SR-71 was dropped at the end of the
Cold War, then brought back during the
1990s. They were used also in the Gulf War.
The last SR-71 flight was in October 2001.
A ramjet is a form of jet engine that contains
no major moving parts and can be
particularly useful in applications requiring a
Scramjet aircraft
The X-43A, shortly after booster ignition
Scramjet aircraft are in the experimental
stage. The Boeing X-43 is an experimental
scramjet with a world speed record for a jetpowered aircraft - Mach 9.7, nearly 12,000
km/h (≈ 7,000 mph) at an altitude of about
36,000 meters (≈ 110,000 ft). The X-43A set
the flight speed record on 16 November
2004.
[edit] History
Main articles: Aviation history and First flying machine
Heavier-than-air flying machines are impossible.[4]
“
”
— Lord Kelvin
The dream of flight goes back to the days of pre-history. Many stories from antiquity involve
flight, such as the Greek legend of Icarus and Daedalus, and the Vimana in ancient Indian epics.
Around 400 BC, Archytas, the Ancient Greek philosopher, mathematician, astronomer,
statesman, and strategist, was reputed to have designed and built the first artificial, self-propelled
flying device, a bird-shaped model propelled by a jet of what was probably steam, said to have
actually flown some 200 meters.[5][6] This machine, which its inventor called The Pigeon (Greek:
Περιστέρα "Peristera"), may have been suspended on a wire or pivot for its flight.[7][8] Amongst
the first recorded attempts at aviation were the attempts made by Yuan Huangtou in the 6th
century and by Abbas Ibn Firnas in the 9th century. Leonardo da Vinci researched the wing
design of birds and designed a man-powered aircraft in his Codex on the Flight of Birds (1502).
In the 1630s, Lagari Hasan Çelebi flew in a rocket artificially powered by gunpowder. In the
18th century, Francois Pilatre de Rozier and Francois d'Arlandes flew in an aircraft lighter than
air, a balloon. The biggest challenge became to create other craft, capable of controlled flight.
Le Bris and his glider, Albatros II, photographed by Nadar, 1868
Sir George Cayley, the founder of the science of aerodynamics, was building and flying models
of fixed-wing aircraft as early as 1803, and he built a successful passenger-carrying glider in
1853.[9] In 1856, Frenchman Jean-Marie Le Bris made the first powered flight, by having his
glider "L'Albatros artificiel" pulled by a horse on a beach. On 28 August 1883, the American
John J. Montgomery made a controlled flight in a glider. Other aviators who had made similar
flights at that time were Otto Lilienthal, Percy Pilcher and Octave Chanute.
The first self-powered aircraft was created by an Englishman by the name of John Stringfellow
of Chard in Somerset, who created a self-powered model aircraft that had its first successful
flight in 1848.
Clément Ader constructed and designed a self-powered aircraft. On October 9, 1890, Ader
attempted to fly the Éole, which succeeded in taking off and flying uncontrolled a distance of
approximately 50 meters before witnesses. In August 1892 the Avion II flew for a distance of
200 meters, and on October 14, 1897, Avion III flew a distance of more than 300 meters.
Richard Pearse made a poorly documented uncontrolled flight on March 31, 1903 in Waitohi,
New Zealand, and on August 28, 1903 in Hanover, the German Karl Jatho made his first
flight.[citation needed]
The Wright Brothers made their first successful test flights on December 17, 1903. This flight is
recognized by the Fédération Aéronautique Internationale (FAI), the standard setting and recordkeeping body for aeronautics and astronautics, as "the first sustained and controlled heavier-thanair powered flight".[10] By 1905, the Wright Flyer III was capable of fully controllable, stable
flight for substantial periods.
Alberto Santos-Dumont a Brazilian living in France, built the first practical dirigible balloons at
the end of the nineteenth century. In 1906 he flew the first fixed wing aircraft in Europe, the 14bis, which was of his and Gabriel Voisin's design. A later design of his, the Demoiselle,
introduced ailerons and brought all around pilot control during a flight.[11]
Santos Dumont, the aviation's father, the
builder of the first aircraft capable of taking
off, flying, and landing without the use of
catapults or high winds.
World War I served as a testbed for the use
of the aircraft as a weapon. Initially seen by
the generals as a "toy", aircraft demonstrated
their potential as mobile observation
platforms, then proved themselves to be
machines of war capable of causing
casualties to the enemy. "Fighter aces"
appeared, described as "knights of the air",
the greatest was the German Manfred von
Richthofen, the Red Baron. On the side of
the allies, the ace with the highest number of
downed aircraft was René Fonck, of France.
Following the war, aircraft technology continued to develop. Alcock and Brown crossed the
Atlantic non-stop for the first time in 1919, a feat first performed solo by Charles Lindbergh in
1927. The first commercial flights took place between the United States and Canada in 1919.
The turbine or the jet engine was in development in the 1930s; military jet aircraft began
operating in the 1940s.
Aircraft played a primary role in the Second World War, having a presence in all the major
battles of the war, Pearl Harbor, the battles of the Pacific, the Battle of Britain. They were an
essential component of the military strategies of the period, such as the German Blitzkrieg or the
American and Japanese aircraft carrier campaigns of the Pacific.
In October 1947, Chuck Yeager was the first person to exceed the speed of sound, flying the Bell
X-1.
Aircraft in a civil military role continued to feed and supply Berlin in 1948, when access to
railroads and roads to the city, completely surrounded by Eastern Germany, were blocked, by
order of the Soviet Union.
The first commercial jet, the de Havilland Comet, was introduced in 1952. A few Boeing 707s,
the first widely successful commercial jet, are still in service after nearly 50 years. The Boeing
727 was another widely used passenger aircraft, and the Boeing 747 was the world's biggest
commercial aircraft between 1970 and 2005, when it was surpassed by the Airbus A380.
[edit] Designing and constructing an aircraft
Small aircraft can be designed and constructed by amateurs as homebuilts, such as Chris Neil's
Woody Helicopter. Other aviators with less knowledge make their aircraft using premanufactured kits, assembling the parts into a complete aircraft.
Most aircraft are constructed by companies with the objective of producing them in quantity for
customers. The design and planning process, including safety tests, can last up to four years for
small turboprops, and up to 12 years for aircraft with the capacity of the A380.
During this process, the objectives and design specifications of the aircraft are established. First
the construction company uses drawings and equations, simulations, wind tunnel tests and
experience to predict the behavior of the aircraft. Computers are used by companies to draw,
plan and do initial simulations of the aircraft. Small models and mockups of all or certain parts of
the aircraft are then tested in wind tunnels to verify the aerodynamics of the aircraft.
When the design has passed through these processes, the company constructs a limited number
of these aircraft for testing on the ground. Representatives from an aviation governing agency
often make a first flight. The flight tests continue until the aircraft has fulfilled all the
requirements. Then, the governing public agency of aviation of the country authorizes the
company to begin production of the aircraft.
In the United States, this agency is the Federal Aviation Administration (FAA), and in the
European Union, Joint Aviation Authorities (JAA). In Canada, the public agency in charge and
authorizing the mass production of aircraft is Transport Canada.
In the case of the international sales of aircraft, a license from the public agency of aviation or
transports of the country where the aircraft is also to be used is necessary. For example, aircraft
from Airbus need to be certified by the FAA to be flown in the United States and vice versa,
aircraft of Boeing need to be approved by the JAA to be flown in the European Union.
Quieter aircraft are becoming more and more needed due to the increase in air traffic,
particularly over urban areas, as noise pollution is a major concern. MIT and Cambridge
University have been designing delta-wing aircraft that are 25 times more silent (63 dB) than
current craft and can be used for military and commercial purposes. The project is called the
Silent Aircraft Initiative, but production models will not be available until around 2030.[3]
[edit] Industrialized production
There are few companies that produce aircraft on a large scale. However, the production of an
aircraft for one company is a process that actually involves dozens, or even hundreds, of other
companies and plants, that produce the parts that go into the aircraft. For example, one company
can be responsible for the production of the landing gear, while another one is responsible for the
radar. The production of such parts is not limited to the same city or country; in the case of large
aircraft manufacturing companies, such parts can come from all over the world.
The parts are sent to the main plant of the aircraft company, where the production line is located.
In the case of large aircraft, production lines dedicated to the assembly of certain parts of the
aircraft can exist, especially the wings and the fuselage.
When complete, an aircraft goes through a set of rigorous inspection, to search for imperfections
and defects, and after being approved by the inspectors, the aircraft is tested by a pilot, in a flight
test, in order to assure that the controls of the aircraft are working properly. With this final test,
the aircraft is ready to receive the "final touchups" (internal configuration, painting, etc), and is
then ready for the customer.
Balloon (aircraft)
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removed. (April 2008)
"Ballooning" redirects here. For the behavior of spiders and other arthropods, see
Ballooning (spider).
Balloon
A balloon is a type of aircraft that remains aloft due to its buoyancy. A balloon travels by
moving with the wind. It is distinct from an airship, which is a buoyant aircraft that can be
propelled through the air in a controlled manner.
[edit] Types of balloon aircraft
The DHL Balloon is the world's largest
tethered helium balloon.
There are three main types of balloon
aircraft:
•
•
Hot air balloons obtain their
buoyancy by heating the air inside
the balloon. They are the most
common type of balloon aircraft.
"Hot air balloon" is sometimes used
incorrectly to denote any balloon that
carries people.
Gas balloons are inflated with a gas
of lower molecular weight than the
ambient atmosphere. Most gas
balloons operate with the internal
pressure of the gas being the same as
•
the pressure of the surrounding
atmosphere. There is a type of gas
balloon, called a superpressure
balloon, that can operate with the
lifting gas at pressure that exceeds
the pressure of the surrounding air,
with the objective of limiting or
eliminating the loss of gas from daytime heating. Gas balloons are filled
with gases such as:
o hydrogen - not widely used
for aircraft since the
Hindenburg disaster because
of high flammability (except
for some sport balloons as
well as nearly all unmanned
scientific and weather
balloons).
o helium - the gas used today
for all airships and most
manned balloons.
o ammonia - used infrequently
due to its caustic qualities and
limited lift.
o coal gas - used in the early
days of ballooning; it is
highly flammable.
Rozière balloons use both heated and
unheated lifting gases. The most
common modern use of this type of
balloon is for long-distance record
flights such as the recent
circumnavigations.
[edit] History
Main article: History of ballooning
A modern Kongming Lantern
The hot air balloon Kongming lantern was
developed for military communications
around the second or third century AD in
China. It is thought that some ancient
civilizations may have developed manned
hot air balloon flight. For example, the
Nazca lines (which are best seen from the
air) allegedly presuppose some form of
manned flight, such as a balloon.
In 1710 in Lisbon, Bartolomeu de Gusmão made a balloon filled with heated air rise inside a
room. He also made a balloon named Passarola (English: Big bird) and attempted to lift himself
from Saint George Castle in Lisbon, but only managed to harmlessly fall about one kilometre
away. According to the Portuguese speaking community, this was the first man ever to fly in
human history. However, this claim is not generally recognized by aviation historians outside the
Portuguese speaking community, in particular the FAI.
Following Henry Cavendish's 1766 work on hydrogen, Joseph Black proposed that a balloon
filled with hydrogen would be able to rise in the air.
A model of the Montgolfier brothers balloon
at the London Science Museum
The first recorded manned flight was made
in a hot air balloon built by the Montgolfier
brothers on November 21, 1783. The flight
started in Paris and reached a height of 500
feet or so. The pilots, Jean-François Pilâtre
de Rozier and François Laurent d'Arlandes,
covered about 5 1/2 miles in 25 minutes.
Only a few days later, on December 1, 1783, Professor Jacques Charles and Nicholas Louis
Robert made the first gas balloon flight, also from Paris. The hydrogen filled balloon flew to
almost 2,000 feet (600 m), stayed aloft for over 2 hours and covered a distance of
27 miles (43 km), landing in the small town of Nesle.
The first aircraft disaster occurred in May 1785 when the town of Tullamore, County Offaly,
Ireland was seriously damaged when the crash of a balloon resulted in a fire that burned down
about 100 houses, making the town home to the world's first aviation disaster. To this day, the
town shield depicts a phoenix rising from the ashes.
Balloon landing in Mashgh square, Iran
(Persia), at the time of Nasser al-Din Shah
Qajar, around 1850.
Blanchard went on to make the first manned
flight of a balloon in America on January 9,
1793. His hydrogen filled balloon took off
from a prison yard in Philadelphia,
Pennsylvania. The flight reached
5,800 feet (1,770 m) and landed in
Gloucester County, New Jersey. President
George Washington was among the guests
observing the takeoff.
Gas balloons became the most common type from the 1790s until the 1960s.
The first steerable balloon (also known as a dirigible) was flown by Henri Giffard in 1852.
Powered by a steam engine, it was too slow to be effective. Like heavier than air flight, the
internal combustion engine made dirigibles – especially blimps – practical, starting in the late
19th century. In 1872 Paul Haenlein flew the first (tethered) internal combustion motor powered
balloon. The first to fly in an untethered airship powered by an internal combustion engine was
Alberto Santos Dumont in 1898.
Henri Giffardalso developed a tethered balloon for passengers in 1878 in the Tuileries Garden in
Paris. The first tethered balloon in modern times was made in France at Chantilly Castle in 1994
by Aérophile SA.
Ed Yost redesigned the hot air balloon in the late 1950s using rip-stop nylon fabrics and highpowered propane burners to create the modern hot air balloon. His first flight of such a balloon,
lasting 25 minutes and covering 3 miles (5 km), occurred on October 22, 1960 in Bruning,
Nebraska. Yost's improved design for hot air balloons triggered the modern sport balloon
movement. Today, hot air balloons are much more common than gas balloons.
Events in the early history of ballooning; collecting cards from the late 19th century.
[edit] Balloons as flying machines
A tethered helium balloon gives the public
rides to 500 feet (150 m) above the city of
Bristol, England. The inset shows detail of
the gondola.
A balloon is conceptually the simplest of all
flying machines. The balloon is a fabric
envelope filled with a gas that is lighter than
the surrounding atmosphere.
As the entire balloon is less dense than its surroundings, it rises, taking along with it a basket,
attached underneath, that carries passengers or payload. Although a balloon has no propulsion
system, a degree of directional control is possible through making the balloon rise or sink in
altitude to find favorable wind directions.
The first balloons capable of carrying passengers used hot air to obtain buoyancy and were built
by the brothers Josef and Etienne Montgolfier in Annonay, France.
Balloons using the light gas hydrogen for buoyancy were flown less than a month later. They
were invented by Professor Jacques Charles and first flown on December 1, 1783. Gas balloons
have greater lift and can be flown much longer than hot air, so gas balloons dominated
ballooning for the next 200 years. In the 19th century, it was common to use town gas to fill
balloons; it was not as light as pure hydrogen gas, but was much cheaper and readily available.
The third balloon type was invented by Pilâtre de Rozier and is a hybrid of a hot air and a gas
balloon. Gas balloons have an advantage of being able to fly for a long time, and hot air balloons
have an advantage of being able to easily change altitude, so the Rozier balloon was a hydrogen
balloon with a separate hot air balloon attached. In 1785, Pilâtre de Rozier took off in an attempt
to fly across the English Channel, but the balloon exploded a half-hour into the flight. This
accident earned de Rozier the title "The First to Fly and the First to Die". It wasn't until the 1980s
that technology once again allowed the Rozier balloons to become feasible.
Jean-Pierre Blanchard made the first piloted
balloon flight in North America on January
9, 1793.
Hot air balloons, San Diego, California
Both the hot air, or Montgolfière, balloon
and the gas balloon are still in common use.
Montgolfière balloons are relatively
inexpensive as they do not require highgrade materials for their envelopes, and they
are popular for balloonist sport activity.
A new way of flying in a gas balloon is with a tether. Notable balloons are in Paris since 1999, in
Berlin since 2000, in Disneyland Resort Paris since 2005 with more than 100 000 passengers per
year, and the DHL Balloon in Singapore since 2006. All of them have been made by Aerophile
SA. Aerophile Balloon is also operated in the San Diego Wild Animal Park in California which
has been in operation since the year 2005.
Gas balloons at the Albuquerque
International Balloon Fiesta
Light gas balloons are predominant in
scientific applications, as they are capable of
reaching much higher altitudes for much
longer periods of time.
They are generally filled with helium. Although hydrogen has more lifting power, it is explosive
in an atmosphere full of oxygen. With a few exceptions, scientific balloon missions are
unmanned.
There are two types of light-gas balloons: zero-pressure and superpressure. Zero-pressure
balloons are the traditional form of light-gas balloon. They are partially inflated with the light
gas before launch, with the gas pressure the same both inside and outside the balloon. As the
zero-pressure balloon rises, its gas expands to maintain the zero pressure difference, and the
balloon's envelope swells.
At night, the gas in a zero-pressure balloon cools and contracts, causing the balloon to sink. A
zero-pressure balloon can only maintain altitude by releasing gas when it goes too high, where
the expanding gas can threaten to rupture the envelope, or releasing ballast when it sinks too low.
Loss of gas and ballast limits the endurance of zero-pressure balloons to a few days.
A special-shape hot air balloon - Chubb fire
extinguisher
A superpressure balloon, in contrast, has a
tough and inelastic envelope that is filled
with light gas to pressure higher than that of
the external atmosphere, and then sealed.
The superpressure balloon cannot change
size greatly, and so maintains a generally
constant volume. The superpressure balloon
maintains an altitude of constant density in
the atmosphere, and can maintain flight until
gas leakage gradually brings it down.
Superpressure balloons offer flight endurance of months, rather than days. In fact, in typical
operation an Earth-based superpressure balloon mission is ended by a command from ground
control to open the envelope, rather than by natural leakage of gas.
For air transport balloons must contain a gas lighter than the surrounding air. There are two
types:
•
•
Hot air balloon: filled with hot air, which by heating becomes lighter than the
surrounding air; they have been used to carry human passengers since the 1790s;
Balloons filled with:
o hydrogen - highly flammable (see Hindenburg disaster)
o helium - safe if used properly, but very expensive.
Large helium balloons are used as high flying vessels to carry scientific instruments (as do
weather balloons), or even human passengers with a tether like in Paris, Berlin, Hong Kong or
Singapore.
Cluster ballooning uses many smaller gas-filled balloons for flight (see An Introduction to
Cluster Ballooning).
[edit] Balloons in the military
Main article: History of military ballooning
See also: Observation balloon
The first military use of a balloon was at the Battle of Fleurus in 1794, when L'Entreprenant was
used by French Revolutionary troops to watch the movements of the enemy. On April 2, 1794,
an aeronauts corps was created in the French army; however, given the logistical problems
linked with the production of hydrogen on the battlefield (it required constructing ovens and
pouring water on white-hot iron), the corps was disbanded in 1799.
[edit] American Civil War
The Union Army Balloon Intrepid being
inflated from the gas generators for the
Battle of Fair Oaks
The first major-scale use of balloons in the
military occurred during the American Civil
War with the Union Army Balloon Corps
established and organized by Prof. Thaddeus
S. C. Lowe in the summer of 1861.
Originally, the balloons were inflated with
coal gas from municipal services and then
walked out to the battlefield, an arduous and
inefficient operation as the balloons had to
be returned to the city every four days for reinflation. Eventually hydrogen gas
generators, a compact system of tanks and
copper plumbing, were constructed which
converted the combining of iron filings and
sulfuric acid to hydrogen. The generators
were easily transported with the uninflated
balloons to the field on a standard
buckboard. In all, Lowe built seven balloons
that were fit for military service.
The first application thought useful for balloons was map-making from aerial vantage points,
thus Lowe's first assignment was with the Topographical Engineers. General Irvin McDowell,
commander of the Army of the Potomac, realized their value in aerial reconnaissance and had
Lowe, who at the time was using his personal balloon the Enterprise, called up to the First Battle
of Bull Run. Lowe also worked as a Forward Artillery Observer (FAO) by directing artillery fire
via flag signals. This enabled gunners on the ground to fire accurately at targets they could not
see, a military first.
Lowe's first military balloon, the Eagle was ready by October 1, 1861. It was called into service
immediately to be towed to Lewinsville, Virginia, without any gas generator which took longer
to build. The trip began after inflation in Washington, D.C. and turned into a 12 mile (19 km),
12-hour excursion that was upended by a gale force wind which ripped the aerostat from its
netting and sent it sailing to the coast. Balloon activities were suspended until all balloons and
gas generators were completed.
With his ability to inflate balloons from remote stations, Lowe, his new balloon the Washington
and two gas generators were loaded onto a converted coal barge the George Washington Parke
Custis. As he was towed down the Potomac, Lowe was able to ascend and observe the battlefield
as it moved inward on the heavily forested peninsula. This would be the military's first claim of
an aircraft carrier.
The Union Army Balloon Corps enjoyed more success in the battles of the Peninsula Campaign
than the Army of the Potomac it sought to support. The general military attitude toward the use
of balloons deteriorated, and by August 1863 the Balloon Corps was disbanded.
The Confederate Army also made use of balloons, but they were gravely hampered by supplies
due to the embargoes. They were forced to fashion their balloons from colored silk dress-making
material, and their use was limited by the infrequent supply of gas in Richmond, Virginia. By the
summer of 1863, all balloon reconnaissance of the Civil War had ceased.
[edit] Countries
In Britain during July 1863, experimental balloon ascents for reconnaissance purposes were
conducted by the Royal Engineers on behalf of the British Army, but although the experiments
were successful it was considered not worth pursuing further because it was too expensive.
However by 1888 a School of Ballooning was established at Chatham, Medway, Kent. It moved
to Stanhope Lines, Aldershot in 1890 when a balloon section and depot were formed as
permanent units of the Royal Engineers establishment.
During the Paraguayan War, balloons were also used for observation by the Brazilian Army.
Balloons were used by the Royal Engineers for reconnaissance and observation purposes during
the Bechuanaland Expedition (1885), the Sudan Expedition (1885) and during the Anglo-Boer
War (1899-1902). On October 5, 1907 Colonel John Capper (late Royal Engineers) and team
flew the military airship Nulli Secundus from Farnborough round St Paul's Cathedral in London
and back with a view to raising public interest.
Close-up view of an American major in the
basket of an observation balloon flying over
territory near front lines during World War
I.
Hydrogen-filled balloons were also widely
used during World War I (1914-1918) to
detect enemy troop movements and to direct
artillery fire. Observers phoned their reports
to officers on the ground who then relayed
the information to those who needed it.
Balloons were frequently targets of opposing
aircraft. Planes assigned to attack enemy
balloons were often equipped with
incendiary bullets, for the purpose of
igniting the hydrogen.
The Aeronaut Badge was established by the United States Army in World War I to denote
service members who were qualified balloon pilots. Observation balloons were retained well
after the Great War, being used in the Russo-Finnish conflicts (1939-40 and 1941-45).
The Japanese launched thousands of balloon bombs to the US and Canada, carried in the jet
stream; see fire balloon. The British used balloons to carry incendiary devices to Germany
between 1942 and 1944; see Operation Outward.
[edit] Records
On May 27, 1931, Auguste Piccard and Paul Kipfer became the first to reach the stratosphere in
a balloon.[1]
On March 1, 1999 Bertrand Piccard and Brian Jones set off in the balloon Breitling Orbiter 3
from Château d'Oex in Switzerland on the first non-stop balloon circumnavigation around the
globe. They landed in Egypt after a 45,755 kilometers flight lasting 19 days, 21 hours and 47
minutes.
On August 31, 1933, Alexander Dahl took the first picture of the earth's curvature in an open
hydrogen gas balloon.
The altitude record for a manned balloon was set at 34,668 meters on May 4, 1961 by Malcolm
Ross and Victor Prather in the Stratolab V balloon payload launched from the deck of the USS
Antietam in the Gulf of Mexico.
The altitude record for an unmanned balloon is 53.0 kilometres, reached with a volume of 60,000
cubic metres. The balloon was launched by JAXA in May 25 2002 from Iwate Prefecture,
Japan[2]. This is the greatest height ever obtained by an atmospheric vehicle. Only rockets, rocket
planes, and ballistic projectiles have flown higher.
[edit] Balloons in space
The Echo satellite was a balloon launched into Earth orbit in 1960 and used for passive relay of
radio communication.
In 1984 the Soviet space probes Vega 1 and Vega 2 released two balloons with scientific
experiments in the atmosphere of Venus. They transmitted signals for two days to Earth.
[edit] Balloons in literature
Jules Verne wrote a non fiction story about being stranded in a hydrogen balloon, see [1]
Bicycle
From Wikipedia, the free encyclopedia
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Wooden Dandy horse (around 1820), the
first two-wheeler and as such the archetype
of the bicycle
A common utility bicycle
The bicycle, bike, or cycle is a pedal-driven, human-powered vehicle with two wheels attached
to a frame, one behind the other.
Bicycles were introduced in the 19th century and now number about one billion worldwide.[1]
They are the principal means of transportation in many regions. They also provide a popular
form of recreation, and have been adapted for such uses as children's toys, adult fitness, military
and police applications, courier services, and competitive sports.
The basic shape and configuration of a typical bicycle has changed little since the first chaindriven model was developed around 1885.[2] Many details have been improved, especially since
the advent of modern materials and computer-aided design. These have allowed for a
proliferation of specialized designs for particular types of cycling.
The bicycle has had a considerable effect on human society, in both the cultural and industrial
realms. In its early years, bicycle construction drew on pre-existing technologies; more recently,
bicycle technology has, in turn, contributed both to old and new areas.
History
Main article: History of the bicycle
Multiple innovators contributed to the history of the bicycle by developing precursor humanpowered vehicles. The documented ancestors of today's modern bicycle were known as push
bikes (still called push bikes outside of North America), draisines, or hobby horses. Being the
first human means of transport to make use of the two-wheeler principle, the draisine (or
mistmashine, "running machine"), invented by the German Baron Karl von Drais, is regarded as
the archetype of the bicycle. It was introduced by Drais to the public in Mannheim in summer
1817 and in Paris in 1818.[3] Its rider sat astride a wooden frame supported by two in-line wheels
and pushed the vehicle along with his/her feet while steering the front wheel.
A penny-farthing or ordinary bicycle
photographed in the Škoda Auto museum in
the Czech Republic
In the early 1860s, Frenchmen Pierre
Michaux and Pierre Lallement took bicycle
design in a new direction by adding a
mechanical crank drive with pedals on an
enlarged front wheel. Another French
inventor by the name of Douglas Grasso had
a failed prototype of Pierre Lallement's
bicycle several years earlier. Several whynot-the-rear-wheel inventions followed, the
best known being the rod-driven velocipede
by Scotsman Thomas McCall in 1869. The
French creation, made of iron and wood,
developed into the "penny-farthing" (more
formally an "ordinary bicycle", a retronym,
since there were then no other kind).[4] It
featured a tubular steel frame on which were
mounted wire spoked wheels with solid
rubber tires. These bicycles were difficult to
ride due to their very high seat and poor
weight distribution.
Bicycle in Plymouth, England at the start of
the 20th century
The dwarf ordinary addressed some of these
faults by reducing the front wheel diameter
and setting the seat further back. This
necessitated the addition of gearing, effected
in a variety of ways, to attain sufficient
speed. Having to both pedal and steer via the
front wheel remained a problem. J. K.
Starley, J. H. Lawson, and Shergold solved
this problem by introducing the chain drive
(originated by Henry Lawson's unsuccessful
"bicyclette"),[5] connecting the framemounted pedals to the rear wheel. These
models were known as dwarf safeties, or
safety bicycles, for their lower seat height
and better weight distribution. Starley's 1885
Rover is usually described as the first
recognizably modern bicycle. Soon, the seat
tube was added, creating the double-triangle
diamond frame of the modern bike.
Further innovations increased comfort and ushered in a second bicycle craze, the 1890s' Golden
Age of Bicycles. In 1888, Scotsman John Boyd Dunlop introduced the pneumatic tire, which
soon became universal. Soon after, the rear freewheel was developed, enabling the rider to coast.
This refinement led to the 1898 invention of coaster brakes. Derailleur gears and hand-operated
cable-pull brakes were also developed during these years, but were only slowly adopted by
casual riders. By the turn of the century, cycling clubs flourished on both sides of the Atlantic,
and touring and racing became widely popular.
Bicycles and horse buggies were the two mainstays of private transportation just prior to the
automobile, and the grading of smooth roads in the late 19th century was stimulated by the
widespread advertising, production, and use of these devices.
[edit] Uses for bicycles
Working bicycle in Amsterdam,
Netherlands.
Transporting milk churns in Kolkata, India.
Bicycles have been and are employed for
many uses:
•
•
•
•
•
•
•
Utility: bicycle commuting and utility cycling
Work: mail delivery, paramedics, police, and general delivery.
Recreation: bicycle touring, mountain biking, BMX and physical fitness.
Racing: track racing, criterium, roller racing and time trial to multi-stage events like the
Tour of California, Giro d'Italia, the Tour de France, the Vuelta a España, the Volta a
Portugal, among others.
Military: scouting, troop movement, supply of provisions, and patrol. See bicycle
infantry.
Show: entertainment and performance, e.g. circus clowns. Used as instrument by Frank
Zappa.
Power: electricity for electronics can be generated by bicycle.
[edit] Technical aspects
A Half Wheeler trailer bike at the Golden
Gate Bridge
The bicycle has undergone continual
adaptation and improvement since its
inception. These innovations have continued
with the advent of modern materials and
computer-aided design, allowing for a
proliferation of specialized bicycle types.
[edit] Types of bicycles
Main article: List of bicycle types
Bicycles can be categorized in different ways: e.g. by function, by number of riders, by general
construction, by gearing or by means of propulsion. The more common types include utility
bicycles, mountain bicycles, racing bicycles, touring bicycles, hybrid bicycles, cruiser bicycles,
and BMX bicycles. Less common are tandems, lowriders, tall bikes, fixed gear (fixed-wheel),
folding models and recumbents (one of which was used to set the IHPVA Hour record).
Unicycles, tricycles and quadracycles are not strictly bicycles, as they have respectively one,
three and four wheels, but are often referred to informally as "bikes".
[edit] Dynamics
Main article: Bicycle and motorcycle
dynamics
Bicycles leaning in a turn
A bicycle stays upright by being steered so
as to keep its center of gravity over its
wheels. This steering is usually provided by
the rider, but under certain conditions may
be provided by the bicycle itself.
A bicycle must lean in order to turn. This lean is induced by a method known as countersteering,
which can be performed by the rider turning the handlebars directly with the hands or indirectly
by leaning the bicycle.
Short-wheelbase or tall bicycles, when braking, can generate enough stopping force at the front
wheel in order to flip longitudinally. The act of purposefully using this force to lift the rear wheel
and balance on the front without tipping over is a trick known as a stoppie, endo or front wheelie.
[edit] Performance
Main article: Bicycle performance
A racing upright bicycle
The bicycle is extraordinarily efficient in
both biological and mechanical terms. The
bicycle is the most efficient self-powered
means of transportation in terms of energy a
person must expend to travel a given
distance.[6] From a mechanical viewpoint, up
to 99% of the energy delivered by the rider
into the pedals is transmitted to the wheels,
although the use of gearing mechanisms
may reduce this by 10-15%.[7][8] In terms of
the ratio of cargo weight a bicycle can carry
to total weight, it is also a most efficient
means of cargo transportation.
A recumbent bicycle
A human being traveling on a bicycle at low
to medium speeds of around 10-15 mph (1525 km/h), using only the energy required to
walk, is the most energy-efficient means of
transport generally available. Air drag,
which is proportional to the square of speed,
requires dramatically higher power outputs
as speeds increase. A bicycle which places
the rider in a seated position, supine position
or, more rarely, prone position, and which
may be covered in an aerodynamic fairing to
achieve very low air drag, is referred to as a
recumbent bicycle or human powered
vehicle. On an upright bicycle, the rider's
body creates about 75% of the total drag of
the bicycle/rider combination.
In addition, the carbon dioxide generated in the production and transportation of the food
required by the bicyclist, per mile traveled, is less than 1/10th that generated by energy efficient
cars.[9]
[edit] Construction and parts
In its early years, bicycle construction drew on pre-existing technologies. More recently, bicycle
technology has in turn contributed ideas in both old and new areas.
Frame
Main article: Bicycle frame
Diagram of a bicycle.
The great majority of today's bicycles have a
frame with upright seating which looks
much like the first chain-driven bike.[2] Such
upright bicycles almost always feature the
diamond frame, a truss consisting of two
triangles: the front triangle and the rear
triangle. The front triangle consists of the
head tube, top tube, down tube and seat tube.
The head tube contains the headset, the set
of bearings that allows the fork to turn
smoothly for steering and balance. The top
tube connects the head tube to the seat tube
at the top, and the down tube connects the
head tube to the bottom bracket. The rear
triangle consists of the seat tube and paired
chain stays and seat stays. The chain stays
run parallel to the chain, connecting the
bottom bracket to the rear dropouts. The seat
stays connect the top of the seat tube (at or
near the same point as the top tube) to the
rear dropouts.
A Triumph with a step-through frame.
Historically, women's bicycle frames had a
top tube that connected in the middle of the
seat tube instead of the top, resulting in a
lower standover height at the expense of
compromised structural integrity, since this
places a strong bending load in the seat tube,
and bicycle frame members are typically
weak in bending. This design, referred to as
a step-through frame, allows the rider to
mount and dismount in a dignified way
while wearing a skirt or dress. While some
women's bicycles continue to use this frame
style, there is also a variation, the mixte,
which splits the top tube into two small top
tubes that bypass the seat tube and connect
to the rear dropouts. The ease of stepping
through is also appreciated by those with
limited flexibility or other joint problems.
Because of its persistent image as a
"women's" bicycle, step-through frames are
not common for larger frames.
Another style is the recumbent bicycle. These are inherently more aerodynamic than upright
versions, as the rider may lean back onto a support and operate pedals that are on about the same
level as the seat. The world's fastest bicycle is a recumbent bicycle but this type was banned
from competition in 1934 by the Union Cycliste Internationale.[10]
Historically, materials used in bicycles have followed a similar pattern as in aircraft, the goal
being high strength and low weight. Since the late 1930s alloy steels have been used for frame
and fork tubes in higher quality machines. Celluloid found application in mudguards, and
aluminum alloys are increasingly used in components such as handlebars, seat post, and brake
levers. In the 1980s aluminum alloy frames became popular, and their affordability now makes
them common. More expensive carbon fiber and titanium frames are now also available, as well
as advanced steel alloys and even bamboo.
[edit] Drivetrain and gearing
A set of rear sprockets (also known as a
cassette) and a derailleur
For more details on this topic, see
bicycle gearing.
Since cyclists' legs are most efficient over a
narrow range of pedalling speeds (cadence),
a variable gear ratio helps a cyclist to
maintain an optimum pedalling speed while
covering varied terrain. As a first
approximation, utility bicycles often use a
hub gear with a small number (3 to 5) of
widely-spaced gears, road bicycles and
racing bicycles use derailleur gears with a
moderate number (10 to 22) of closelyspaced gears, while mountain bicycles,
hybrid bicycles, and touring bicycles use
dérailleur gears with a larger number (15 to
30) of moderately-spaced gears, often
including an extremely low gear (granny
gear) for climbing steep hills.
Different gears and ranges of gears are appropriate for different people and styles of cycling.
Multi-speed bicycles allow gear selection to suit the circumstances, e.g. it may be comfortable to
use a high gear when cycling downhill, a medium gear when cycling on a flat road, and a low
gear when cycling uphill. In a lower gear every turn of the pedals leads to fewer rotations of the
rear wheel. This allows the energy required to move the same distance to be distributed over
more pedal turns, reducing fatigue when riding uphill, with a heavy load, or against strong
winds. A higher gear allows a cyclist to make fewer pedal cycles to maintain a given speed, but
with more effort per turn of the pedals.
The drivetrain begins with pedals which rotate the cranks, which are held in axis by the bottom
bracket. Most bicycles use a chain to transmit power to the rear wheel. A relatively small number
of bicycles use a shaft drive to transmit power. A very small number of bicycles (mainly singlespeed bicycles intended for short-distance commuting) use a belt drive as an oil-free way of
transmitting power.
A bicycle with shaft drive instead of a chain
With a chain drive transmission, a chainring
attached to a crank drives the chain, which
in turn rotates the rear wheel via the rear
sprocket(s) (cassette or freewheel).
There are four gearing options: two-speed hub gear integrated with chain ring, up to 3 chain
rings, up to 10 sprockets, hub gear built in to rear wheel (3-speed to 14-speed). The most
common options are either a rear hub or multiple chain rings combined with multiple sprockets
(other combinations of options are possible but less common).
With a shaft drive transmission, a gear set at the bottom bracket turns the shaft, which then turns
the rear wheel via a gear set connected to the wheel's hub. There is some small loss of efficiency
due to the two gear sets needed. The only gearing option with a shaft drive is to use a hub gear.
[edit] Steering and seating
A Selle San Marco saddle designed for
women
Conventional dropdown handlebars with
added aerobars
The handlebars turn the fork and the front
wheel via the stem, which rotates within the
headset. Three styles of handlebar are
common. Upright handlebars, the norm in
Europe and elsewhere until the 1970s, curve
gently back toward the rider, offering a
natural grip and comfortable upright
position. Drop handlebars are "dropped",
offering the cyclist either an aerodynamic
"crouched" position or a more upright
posture in which the hands grip the brake
lever mounts. Mountain bikes feature a
straight handlebar which can provide better
low-speed handling due to the wider nature
of the bars.
Saddles also vary with rider preference,
from the cushioned ones favored by shortdistance riders to narrower saddles which
allow more room for leg swings. Comfort
depends on riding position. With comfort
bikes and hybrids the cyclist sits high over
the seat, their weight directed down onto the
saddle, such that a wider and more
cushioned saddle is preferable. For racing
bikes where the rider is bent over, weight is
more evenly distributed between the
handlebars and saddle, the hips are flexed,
and a narrower and harder saddle is more
efficient. Differing saddle designs exist for
male and female cyclists, accommodating
the genders' differing anatomies, although
bikes typically are sold with saddles most
appropriate for men.
A recumbent bicycle has a reclined chair-like seat that some riders find more comfortable than a
saddle, especially riders who suffer from certain types of seat, back, neck, shoulder, or wrist
pain. Recumbent bicycles may have either under-seat or over-seat steering.
[edit] Brakes
Main article: Bicycle brake systems
A front disc brake, mounted to the fork and
hub
Linear-pull brake on rear wheel of a
mountain bike
Modern bicycle brakes are either rim brakes,
in which friction pads are compressed
against the wheel rims, internal hub brakes,
in which the friction pads are contained
within the wheel hubs, or disc brakes. Disc
brakes are common on off-road bicycles,
tandems and recumbent bicycles.
With hand-operated brakes, force is applied
to brake levers mounted on the handlebars
and transmitted via Bowden cables or
hydraulic lines to the friction pads. A rear
hub brake may be either hand-operated or
pedal-actuated, as in the back pedal coaster
brakes which were popular in North
America until the 1960s, and are still
common in children's bicycles.
Track bicycles do not have brakes. Brakes are not required for riding on a track because all riders
ride in the same direction around a track which does not necessitate sharp deceleration. Track
riders are still able to slow down because all track bicycles are fixed-gear, meaning that there is
no freewheel. Without a freewheel, coasting is impossible, so when the rear wheel is moving, the
crank is moving. To slow down one may apply resistance to the pedals.
[edit] Suspension
Main article: Bicycle suspension
brakes and handlebars oriented
perpendicular to the bike's axis
Bicycle suspension refers to the system or
systems used to suspend the rider and all or
part of the bicycle. This serves two
purposes:
This mountain bicycle features oversized
tires, a full-suspension frame, two disc
• To keep the wheels in continuous contact with rough surfaces in order to improve
control.
•
To isolate the rider and luggage from jarring due to rough surfaces.
Bicycle suspensions are used primarily on mountain bicycles, but are also common on hybrid
bicycles, and can even be found on some road bicycles, as they can help deal with problematic
vibration. Suspension is especially important on recumbent bicycles, since while an upright
bicycle rider can stand on the pedals to achieve some of the benefits of suspension, a recumbent
rider cannot.
[edit] Wheels
Main article: Bicycle wheel
The wheel axle fits into dropouts in the frame and forks. A pair of wheels may be called a
wheelset, especially in the context of ready-built "off the shelf", performance-oriented wheels.
Tires vary enormously. Skinny, road-racing tires may be completely smooth, or (slick). On the
opposite extreme, off-road tires are much wider and thicker, and usually have a deep tread for
gripping in muddy conditions.
[edit] Accessories, repairs, and tools
Touring bicycle equipped with head lamp,
pump, rear rack, fenders/mud-guards, water
bottles and cages, and numerous saddlebags.
Puncture repair kit with tire levers,
sandpaper to clean off an area of the inner
tube around the puncture, a tube of rubber
solution (vulcanising fluid), round and oval
patches, a metal grater and piece of chalk to
make chalk powder (to dust over excess
rubber solution). Kits often also include a
wax crayon to mark the puncture location.
Some components, which are often optional accessories on sports bicycles, are standard features
on utility bicycles to enhance their usefulness and comfort. Mudguards, or fenders, protect the
cyclist and moving parts from spray when riding through wet areas and chainguards protect
clothes from oil on the chain while preventing clothing from being caught between the chain and
crankset teeth. Kick stands keep a bicycle upright when parked. Front-mounted baskets for
carrying goods are often used. Luggage carriers and panniers mounted above the rear tire can be
used to carry equipment or cargo. Parents sometimes add rear-mounted child seats and/or an
auxiliary saddle fitted to the crossbar to transport children.
Toe-clips and toestraps and clipless pedals help keep the foot locked in the proper position on the
pedals, and enable the cyclist to pull as well as push the pedals—although not without their
hazards, eg. may lock foot in when needed to prevent a fall. Technical accessories include
cyclocomputers for measuring speed, distance, etc. Other accessories include lights, reflectors,
security locks, mirror, water bottles and cages, and bell.[11]
Bicycle helmets may help reduce injury in the event of a collision or accident, and a certified
helmet is legally required for some riders in some jurisdictions. Helmets are classified as an
accessory[11] or an item of clothing by others.[12]
Many cyclists carry tool kits. These may include a tire patch kit (which, in turn, may contain any
combination of a hand pump or CO2 Pump, tire levers, spare tubes, self-adhesive patches, or
tube-patching material, an adhesive, a piece of sandpaper or a metal grater (to roughing the tube
surface to be patched),[13][14] and sometimes even a block of French chalk.), wrenches, hex keys,
screwdrivers, and a chain tool. There are also cycling specific multi-tools that combine many of
these implements into a single compact device. More specialized bicycle components may
require more complex tools, including proprietary tools specific for a given manufacturer.
Some bicycle parts, particularly hub-based gearing systems, are complex, and many cyclists
prefer to leave maintenance and repairs to professional bicycle mechanics. In some areas it is
possible to purchase road-side assistance from companies such as the Better World Club. Other
cyclists maintain their own bicycles, perhaps as part of their enjoyment of the hobby of cycling
or simply for economic reasons. The ability to repair and maintain your own bicycle is also
celebrated within the DIY movement.
[edit] Standards
A number of formal and industry standards exist for bicycle components to help make spare
parts exchangeable and to maintain a minimum product safety.
The International Organization for Standardization, ISO, has a special technical committee for
cycles, TC149, that has the following scope: "Standardization in the field of cycles, their
components and accessories with particular reference to terminology, testing methods and
requirements for performance and safety, and interchangeability."
CEN, European Committee for Standardisation, also has a specific Technical Committee,
TC333, that defines European standards for cycles. Their mandate states that EN cycle standards
shall harmonise with ISO standards. Some CEN cycle standards were developed before ISO
published their standards, leading to strong European influences in this area. European cycle
standards tend to describe minimum safety requirements, while ISO standards have historically
harmonized parts geometry.[15]
[edit] Parts
For details on specific bicycle parts, see list of bicycle parts and category:bicycle parts.
Social and historical aspects
The bicycle has had a considerable effect on human society, in both the cultural and industrial
realms.
[edit] In daily life
A commuting bike in Amsterdam
Around the turn of the 20th century, bicycles
reduced crowding in inner-city tenements by
allowing workers to commute from more
spacious dwellings in the suburbs. They also
reduced dependence on horses. Bicycles
allowed people to travel for leisure into the
country, since bicycles were three times as
energy efficient as walking and three to four
times as fast.
A bike-sharing station in Barcelona
Recently, several European cities have
implemented successful schemes known as
community bicycle programs or bikesharing. These initiatives complement a
city's public transport system and offer an
alternative to motorized traffic to help
reduce congestion and pollution. Users take
a bicycle at a parking station, use it for a
limited amount of time, and then return it to
the same or different station. Examples
include Bicing in Barcelona, Vélo'v in Lyon
and Vélib' in Paris.
A man uses a bicycle to cargo goods in
Ouagadougou, Burkina Faso (2007)
In cities where the bicycle is not an integral part of the planned transportation system, commuters
often use bicycles as elements of a mixed-mode commute, where the bike is used to travel to and
from train stations or other forms of rapid transit. Folding bicycles are useful in these scenarios,
as they are less cumbersome when carried aboard. Los Angeles removed a small amount of
seating on some trains to make more room for bicycles and wheel chairs [16].
Bicycles offer an important mode of transport in many developing contries. Until recently,
bicycles have been a staple of everyday life throughout Asian countries. They are the most
frequently used method of transport for commuting to work, school, shopping, and life in
general. As a result, bicycles there are almost always equipped with baskets.
[edit] Female emancipation
Woman with bicycle, 1890s
The diamond-frame safety bicycle gave
women unprecedented mobility,
contributing to their emancipation in
Western nations. As bicycles became safer
and cheaper, more women had access to the
personal freedom they embodied, and so the
bicycle came to symbolize the New Woman
of the late nineteenth century, especially in
Britain and the United States.
The bicycle was recognized by nineteenthcentury feminists and suffragists as a
"freedom machine" for women. American
Susan B. Anthony said in a New York World
interview on February 2, 1896: "Let me tell
you what I think of bicycling. I think it has
done more to emancipate women than
anything else in the world. It gives women a
feeling of freedom and self-reliance. I stand
and rejoice every time I see a woman ride by
on a wheel...the picture of free, untrammeled
womanhood." In 1895 Frances Willard, the
tightly-laced president of the Women’s
Christian Temperance Union, wrote a book
called How I Learned to Ride the Bicycle, in
which she praised the bicycle she learned to
ride late in life, and which she named
"Gladys", for its "gladdening effect" on her
health and political optimism. Willard used a
cycling metaphor to urge other suffragists to
action, proclaiming, "I would not waste my
life in friction when it could be turned into
momentum."
Columbia Bicycles advertisement from 1886
Male anger at the freedom symbolized by
the New (bicycling) Woman was
demonstrated when the male undergraduates
of Cambridge University showed their
opposition to the admission of women as
full members of the university by hanging a
woman bicyclist in effigy in the main town
square. This was as late as 1897.[17] The
bicycle craze in the 1890s also led to a
movement for so-called rational dress,
which helped liberate women from corsets
and ankle-length skirts and other restrictive
garments, substituting the then-shocking
bloomers.
[edit] Economic implications
Bicycle manufacturing proved to be a training ground for other industries and led to the
development of advanced metalworking techniques, both for the frames themselves and for
special components such as ball bearings, washers, and sprockets. These techniques later enabled
skilled metalworkers and mechanics to develop the components used in early automobiles and
aircraft.
They also served to teach the industrial models later adopted, including mechanization and mass
production (later copied and adopted by Ford and General Motors),[18] vertical integration[19]
(also later copied and adopted by Ford), aggressive advertising[20] (as much as ten percent of all
advertising in U.S. periodicals in 1898 was by bicycle makers),[21] lobbying for better roads
(which had the side benefit of acting as advertising, and of improving sales by providing more
places to ride),[22] all first practised by Pope.[23] In addition, bicycle makers adopted the annual
model change[24][25] (later derided as planned obsolescence, and usually credited to General
Motors), which proved very successful.[26]
Furthermore, bicycles were an early example of conspicuous consumption, being adopted by the
fashionable elites.[27] In addition, by serving as a platform for accessories, which could ultimately
cost more than the bicycle itself, it paved the way for the likes of the Barbie doll.[28]
Moreover, they helped create, or enhance, new kinds of businesses, such as bicycle
messengers,[29] travelling seamstresses,[30] riding academies,[31] and racing rinks[32] (Their board
tracks were later adapted to early motorcycle and automobile racing.) As well, there were a
variety of new inventions, such as spoke tighteners,[33] and specialized lights,[34] socks and
shoes,[35] and even cameras (such as the Eastman Company's Poco).[36] Probably the best known
and most widely used of these inventions, adopted well beyond cycling, is Charles Bennett's
Bike Web, which came to be called the "jock strap".[37]
They also presaged a move away from public transit[38] that would explode with the introduction
of the automobile. This liberation would be repeated again with the appearance of the
snowmobile.[39]
J. K. Starley's company became the Rover Cycle Company Ltd. in the late 1890s, and then
simply the Rover Company when it started making cars. The Morris Motor Company (in
Oxford) and Škoda also began in the bicycle business, as did the Wright brothers.[40] Alistair
Craig, whose company eventually emerged to become the engine manufacturers Ailsa Craig, also
started from manufacturing bicycles, in Glasgow in March 1885.
In general, U.S. and European cycle manufacturers used to assemble cycles from their own
frames and components made by other companies, although very large companies (such as
Raleigh) used to make almost every part of a bicycle (including bottom brackets, axles, etc.) In
recent years, those bicycle makers have greatly changed their methods of production. Now,
almost none of them produce their own frames.
Many newer or smaller companies only design and market their products; the actual production
is done by Asian companies. For example, some sixty percent of the world's bicycles are now
being made in China. Despite this shift in production, as nations such as China and India become
more wealthy, their own use of bicycles has declined due to the increasing affordability of cars
and motorcycles. One of the major reasons for the proliferation of Chinese-made bicycles in
foreign markets is the lower cost of labour in China.[41]
One of the profound economic implications of bicycle use is that it liberates the user from oil
consumption (Ballantine, 1972). H.G. Wells said: “Every time I see an adult on a bicycle, I no
longer despair for the future of the human race.” (Quotegarden.com[1]). The bicycle is a cheap,
fast, healthy and environmentally friendly mode of transport (Illich, 1974)
[edit] Legal requirements
Reflectors for riding after dark
Early in its development, like in the case of
automobiles, there were restrictions on the
operation of bicycles. Along with
advertising, and to gain free publicity,
Albert A. Pope litigated on behalf of
cyclists[42]
The 1968 Vienna Convention on Road Traffic of the United Nations considers a bicycle to be a
vehicle, and a person controlling a bicycle (whether actually riding or not) is considered an
operator. The traffic codes of many countries reflect these definitions and demand that a bicycle
satisfy certain legal requirements, sometimes even including licensing, before it can be used on
public roads. In many jurisdictions, it is an offence to use a bicycle that is not in roadworthy
condition.
In most jurisdictions, bicycles must have functioning front and rear lights when ridden after dark.
As some generator or dynamo-driven lamps only operate while moving, rear reflectors are
frequently also mandatory. Since a moving bicycle makes little noise, some countries insist that
bicycles have a warning bell for use when approaching pedestrians, equestrians, and other
cyclists.
Boat
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For other uses, see Boat (disambiguation).
A boat ambulance in Venice Italy.
Severn class lifeboat in Poole Harbour,
Dorset, England. This is the largest class of
UK lifeboat at 17 metres long
A boat is a watercraft of modest size
designed to float or plane on water, and
provide transport over it. Usually this water
will be inland (lakes) or in protected coastal
areas. However, boats such as the whaleboat
were designed to be operated from a ship in
an offshore environment. In naval terms, a
boat is something small enough to be carried
aboard another vessel (a ship).
Some boats too large for the naval definition include the Great Lakes freighter, riverboat,
narrowboat and ferryboat. Modern submarines can also be called boats, despite their underwater
capabilities and size. This may be because the first submarines could be carried by a ship and
were not capable of making independent offshore passages. Boats may be used by the military or
other government interests, or for research or commercial purposes; but regardless of size, a
vessel in private, non-commercial usage is almost certainly a boat. In the Royal Navy, a boat is
any submersible, whilst a ship is anything above water, even a rowing boat.
History
A boat in an Egyptian tomb painting from
about 1450 BCE
Boats have served as a method for short
distance transportation since early times, on
slow rivers and calm seas.[1] Circumstantial
evidence, such as the early settlement of
Australia over 40,000 years ago, suggests
that boats have been used since very ancient
times. The earliest boats have been
predicted[2] to be logboats, or possibly boats
made from hide or tree bark. The oldest
boats to be found by archaeological
excavation are logboats from around 70009,000 years ago,[3] [4] though a 7000 year-old
seagoing boat made from reeds and tar has
been found in Kuwait.[5]
Being more capacious than carts and wagons, and suitable for both slow rivers and calm seas,
boats were used between 4000BCE-3000BCE in Sumer,[1] ancient Egypt[6] and in the Indian
Ocean.[1]
Boats played an important part in the commerce between the Indus Valley Civilization and
Mesopotamia.[7] Evidence of varying models of boats has also been discovered in various Indus
Valley sites.[8]
The accounts of historians Herodotus, Pliny the Elder, and Strabo suggest that boats were being
used for commerce and traveling.[8]
Types
Main article: List of boat types
A tug boat, used for towing or pushing
other, larger, vessels.
Normally, boats are categorised into two
types:
•
•
Sailing boats
Motorboats
Sailing boats are boats which are propelled solely by means of sails. Motorboats are boats which
are propelled by mechanical means to propel itself. Motorboats include boats that propel itself
trough the use of both sail and mechanical means.
There are also certain unusual boats which have been used for sports purposes such as bathtub
racing. These boats are made in china. Pumpkins have also been used as boats in Pumpkin Boat
Races. [9]
Parts and terminology
For more details on this topic, see
Glossary of nautical terms.
Common to most boats are several key
components which make up the main
structure of the boat. The hull is the main
structural component of the boat which
provides buoyancy for the boat. The roughly
horizontal, but cambered structures spanning
the hull of the boat are referred to as the
deck. In a ship there are often several decks,
but a boat is unlikely to have more than one.
Above the deck are the superstructures. The
underside of a deck is the deck head.
The hulls of old boats ashore during low
tide.
An enclosed space on a boat is referred to as a cabin. Several individual structures make up a
cabin: the similar but usually lighter structure which spans a raised cabin is a coach-roof. The
"floor" of a cabin is properly known as the sole, but is more likely to be called the floor (a floor
is properly, a structural member which ties a frame to the keelson and keel). The vertical surfaces
dividing the internal space are bulkheads.
The keel is a lengthwise structural member to which the frames are fixed (sometimes referred to
as a backbone).
The front (or forward end) of a boat is called the bow. Boats of earlier times often featured a
figurehead protruding from the front of the bows. The rear (or aft end) of the boat is called the
stern. The right side (facing forward) is starboard and the left side is port.
Building materials
See also: Boat building
A ship's lifeboat, built of steel,
rusting away in the wetlands of Folly
Island, South Carolina
, United States.
Until the mid 19th century most boats were of all natural materials; primarily wood. Many boats
had been built with iron or steel frames but still planked in wood. In 1855 ferro-cement boat
construction was patented by the French. They called it Ferciment. This is a system by which a
steel or iron wire framework is built in the shape of a boat's hull and covered (troweled) over
with cement. Reinforced with bulkheads and other internal structure it is strong but heavy, easily
repaired, and, if sealed properly, will not leak or corrode. These materials and methods were
copied all over the world, and have faded in and out of popularity to the present. As the forests of
Britain and Europe continued to be over-harvested to supply the keels of larger wooden boats,
and the Bessemer process (patented in 1855) cheapened the cost of steel, steel ships and boats
began to be more common. By the 1930s boats built of all steel from frames to plating were seen
replacing wooden boats in many industrial uses, even the fishing fleets. Private recreational boats
in steel are uncommon. In the mid 20th century aluminum gained popularity. Though much more
expensive than steel, there are now aluminum alloys available that will not corrode in salt water,
and an aluminum boat built to similar load carrying standards could be built lighter than steel.
A wooden boat operating near shore.
Around the mid 1960s, boats made out of
glass-reinforced plastic, more commonly
known as fiberglass, became popular,
especially for recreational boats. The coast
guard refers to such boats as 'FRP' (for
Fiberglass Reinforced Plastic) boats.
Fiberglass boats are extremely strong, and
do not rust (iron oxide), corrode, or rot.
They are, however susceptible to structural
degradation from sunlight and extremes in
temperature over their lifespan. Fiberglass
provides structural strength, especially when
long woven strands are laid, sometimes from
bow to stern, and then soaked in epoxy or
polyester resin to form the hull of the boat.
Whether hand laid or built in a mold, FRP boats usually have an outer coating of gelcoat which
is a thin solid colored layer of polyester resin that adds no structural strength, but does create a
smooth surface which can be buffed to a high shine and also acts as a protective layer against
sunlight. FRP structures can be made stiffer with sandwich panels, where the FRP encloses a
lightweight core such as balsa or foam. Cored FRP is most often found in decking which helps
keep down weight that will be carried above the waterline. The addition of wood makes the
cored structure of the boat susceptible to rotting which puts a greater emphasis on not allowing
damaged sandwich structures to go unrepaired. Plastic based foam cores are less vulnerable. The
phrase 'advanced composites' in FRP construction may indicate the addition of carbon fiber,
kevlar(tm) or other similar materials, but it may also indicate other methods designed to
introduce less expensive and, by at least one yacht surveyor's eyewitness accounts[10], less
structurally sound materials.
Cold molding is similar to FRP in as much as it involves the use of epoxy or polyester resins, but
the structural component is wood instead of fiberglass. In cold molding very thin strips of wood
are laid over a form or mold in layers. This layer is then coated with resin and another
directionally alternating layer is laid on top. In some processes the subsequent layers are stapled
or otherwise mechanically fastened to the previous layers, but in other processes the layers are
weighted or even vacuum bagged to hold layers together while the resin sets. Layers are built up
thus to create the required thickness of hull.
People have even made their own boats or watercraft out of commonly available materials such
as foam or plastic, but most homebuilts today are built of plywood and either painted or covered
in a layer of fiberglass and resin.
Propulsion
The most common means are:
The Wanli Emperor enjoying a boat ride on
a river with an entourage of guards and
courtiers in this Ming Dynasty Chinese
painting.
•
•
Human power (rowing, paddling,
setting pole etc.)
Wind power (sailing)
•
Motor powered screws
o Inboard
 Internal Combustion
(gasoline, diesel,
heavy fuel oil)
 Steam (Coal, fuel oil)
 Nuclear (for
submarines and large
naval ships)
o Inboard/Outboard
 Gasoline
 Diesel
o Outboard
 Gasoline
 Electric
o Paddle Wheel
o Water Jet (Personal water
craft, Jetboat)
o Air Fans (Hovercraft, Air
boat)
Buoyancy
See also: Buoyancy
A boat stays afloat because its weight is equal to that of the water it displaces. The material of
the boat itself may be heavier than water (per volume), but it forms only the outer layer. Inside it
is air, which is negligible in weight. But it does add to the volume. The central term here is
density, which is mass per volume. The mass of the boat (plus contents) as a whole has to be
divided by the volume below the waterline. If the boat floats, then that is equal to the density of
water (1 kg/l). To the water it is as if there is water there because the average density is the same.
If weight is added to the boat, the volume below the waterline will have to increase too, to keep
the mass/weight balance equal, so the boat sinks a little to compensate.
Door
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This article is about the architectural feature. For other uses, see Door (disambiguation).
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The front door of a house is often decorated
to appear inviting.
A door is a moveable barrier used to cover
an opening. Doors used widely and are
found in walls or partitions of a building or
space, furniture such as cupboards, cages,
vehicles, and containers.
A door can be opened to give access and
closed more or less securely using a
combination of latches and locks. (See
article Door security).
Doors are nearly universal in buildings of all kinds, allowing passage between the inside and
outside, and between internal rooms. When open, they admit ventilation and light. The door is
used to control the physical atmosphere within a space by enclosing it, excluding air drafts, so
that interiors may be more effectively heated or cooled. Doors are significant in preventing the
spread of fire. They act as a barrier to noise. (See article Door safety).
They are also used to screen areas of a building for aesthetic purposes, keeping formal and utility
areas separate. Doors also have an aesthetic role in creating an impression of what lies beyond.
Doors are often symbolically endowed with ritual purposes, and the guarding or receiving of the
keys to a door, or being granted access to a door can have special significance [1]. Similarly,
doors and doorways frequently appear in metaphorical or allegorical situations, literature and the
arts, often as a portent of change.
[edit] Design and construction styles
A decorated door from the Tibetan
Namdroling monastery, southern India.
Many kinds of doors have specific names,
depending on their purpose. The most
common variety of door consists of a single
rigid panel that fills the doorway. Many
variations on this basic design are possible,
such as "double" doors that have two
adjacent independent panels hinged on each
side of the doorway.
A Dutch door or stable door is divided in half horizontally. Traditionally the top half can be
opened to allow a horse or other animal to be fed, while the bottom half remained closed to keep
the animal inside.
Saloon doors are a pair of lightweight swing doors often found in public bars. Saloon doors, also
known as cafe doors, often use double action hinges, which will return the door to the center,
regardless of which direction it is opened, due to the double action springs in the doors. Saloon
doors that only extend from knee-level to chest-level are known as batwing doors.
A blind door is a door with no visible trim or operable components. It is designed to blend with
the adjacent wall in all finishes, and visually to be a part of the wall, a disguised door.
A barn door is a door characteristic of a barn. They are often/always found on barns, and
because of a barn's immense size (often) doors are subsequently big for utility.
A French door, also called a French window, is a door that has multiple windows ("lights") set
into it for the full length of the door. Traditional French doors are assembled from individual
small pieces of glass and mullions. These doors are also known as true divided lite[sic] French
doors. French doors made of double-pane glass (on exterior doors for insulation reasons) may
have a decorative grille embedded between the panes, or may also be true divided lite French
doors. The decorative grille may also be superimposed on top of single pane of glass in the door.
A louvred door has fixed or movable wooden fins (often called slats or louvers) which permit
open ventilation whilst preserving privacy and preventing the passage of light to the interior.
Being relatively weak structures, they are most commonly used for wardrobes and drying rooms,
where security is of less importance than good ventilation, although a very similar structure is
commonly used to form window shutters.
A flush door is a completely smooth door, having plywood or MDF fixed over a light timber
frame, the hollow parts of which are often filled with a cardboard core material. Flush doors are
most commonly employed in the interior of a dwelling, although slightly more substantial
versions are occasionally used as exterior doors, especially within hotels and other buildings
containing many independent dwellings.
A moulded door has the same structure as that of flush door. The only difference is that the
surface material is a moulded skin made of HDF / MDF. It is commonly used as interior doors.
A ledge and brace door is a door made from multiple vertical planks fixed together by two
horizontal planks (the ledges) and kept square by a diagonal plank (the brace).
A wicket door is a normal sized door built into a much larger one, such as the gate of a city or
castle.
A bifold door is a door unit that has several sections, folding in pairs. Wood is the most common
material, and doors may also be metal or glass. Bifolds are most commonly made for closets, but
may also be used as units between rooms.
A sliding glass door, sometimes called an Arcadia door, is a door made of glass that slides open
and sometimes has a screen.
A false door is a wall decoration that looks like a door. In ancient Egyptian architecture, this was
a common element in a tomb, the false door representing a gate to the afterlife. They can also be
found in the funerary architecture of the desert tribes (e.g., Libyan Ghirza).
[edit] Types of mechanism
[edit] Hinged doors
Most doors are hinged along one side to allow the door to pivot away from the doorway in one
direction but not in the other. The axis of rotation is usually vertical. In some cases, such as
hinged garage doors often horizontal, above the door opening.
Doors can be hinged so that the axis of rotation is not in the plane of the door to reduce the space
required on the side to which the door opens. This requires a mechanism so that the axis of
rotation is on the side other than that in which the door opens. This is sometimes the case in
trains, such as for the door to the toilet, which opens inward.
A swing door has special hinges that allow it to open either outwards or inwards, and is usually
sprung to keep it closed.
A Mead door is a double action pivot door capable of swinging both ways. First introduced by
Scott Mead, established in Leicester, England. The Mead door is susceptible to forced entry.
[edit] Sliding doors
It is often useful to have doors which slide along tracks, often for space or aesthetic
considerations.
A bypass door is a door unit that has two or more sections. The doors can slide in either
direction along one axis on parallel overhead tracks, sliding past each other. They are most
commonly used in closets, in order to access one side of the closet at a time. The doors in a
bypass unit will overlap slightly when viewed from the front, in order not to have a visible gap
between them.
Doors which slide between two wall panels are called pocket doors.
Sliding glass doors are common in many houses, particularly as an entrance to the backyard.
Such doors are also popular for use for the entrances to commercial structures.
A tambour door is made of narrow horizontal slats and "rolls" up and down by sliding along
vertical tracks and is typically found in entertainment centres and cabinets.
[edit] Folding doors
Folding doors have an even number of sections, generally 2 to 4, folding in pairs. The doors can
open from either side for one pair, or fold off both sides for two pairs.
[edit] Rotating doors
A revolving door typically consists of four wings/leaves that hang on a center shaft and rotate
one way about a vertical axis. The door may be motorized, or pushed manually using pushbars.
People can walk out of and into the building at the same time. Between the point of access and
the point of exit the user walks through an airlock. Revolving doors therefore create a good seal
from the outside and help to reduce A/C and heating costs climate control from the building.
This type of door is also often seen as a mark of prestige and glamour for a building and it not
unusual for neighbouring buildings to install their own revolving doors when a rival building
gets one.[citation needed]
A butterfly door is so-called because of its two "wings". It consists of a double-wide panel with
its rotation axle in the centre, effectively creating two separate openings when the door is
opened. Butterfly doors are made to rotate open in one direction (usually counterclockwise), and
rotate closed in the opposite direction. The door is not equipped with handles, so it is a "push"
door. This is for safety, because if it could open in both directions, someone approaching the
door might be caught off-guard by someone else opening the other side, thus impacting the first
person. Such doors are popular in public transit stations, as it has a large capacity, and when the
door is opened, traffic passing in both directions keeps the door open. They are particularly
popular in underground subway stations, because they are heavy, and when air currents are
created by the movement of trains, the force will be applied to both wings of the door, thus
equalizing the force on either side, keeping the door shut.
[edit] Others
An up-and-over door is often used in garages. Instead of hinges it has a mechanism, often
counterbalanced or sprung, that allows it to be lifted so that it rests horizontally above the
opening. Also known as an overhead door.
Automatic doors are powered open and
closed either by power, spring, or both.
There are several methods by which an
automatic door is activated:
Mechanism of the sliding door of an elevator
1. A sensor detects traffic is
approaching. Sensors for automatic
doors are generally:
o A pressure sensor - e.g., a
floor mat which reacts to the
pressure of someone standing
on it.
o An infrared curtain or beam
which shines invisible light
onto sensors; if someone or
something blocks the beam
the door is triggered open.
o A motion sensor which uses
low-power microwave radar
for the same effect.
o A remote sensor (e.g. based
on infrared or radio waves)
can be triggered by a portable
remote control, or is installed
inside a vehicle. These are
popular for garage doors.
2. A switch is operated manually,
perhaps after security checks. This
can be a push button switch or a
swipe card.
3. The act of pushing or pulling the
door triggers the open and close
cycle. These are also known as
power-assisted doors.
In addition to activation sensors automatic doors are generally fitted with safety sensors. These
are usually an infrared curtain or beam, but can be a pressure mat fitted on the swing side of the
door. The purpose of the safety sensor is to prevent the door from colliding with an object in its
path by stopping or slowing its motion.
Inward opening doors are doors that can only be opened (or forced open) from outside a
building. Such doors pose a substantial fire risk to occupants of occupied buildings when they
are locked. As such doors can only be forced open from the outside, building occupants would be
prevented from escaping. In commercial and retail situations manufacturers have included in the
design a mechanism that allows an inward opening door to be pushed open outwards in the event
of an emergency (which is often a regulatory requirement). This is known as a 'breakaway'
feature. Pushing the door outward at its closed position, through a switch mechanism,
disconnects power to the latch and allows the door to swing outward. Upon returning the door to
the closed position, power is restored.
[edit] Applications
Doors have numerous general and specialized uses in buildings, storage devices, vehicles, etc. In
building interiors, doors are generally used to separate interior spaces, rooms, closets, etc. for
privacy, convenience, and safety reasons. Doors are also used to secure passages into a building
from the exterior for reasons of safety and climate control.
Other than these common usages, doors also have the following applications:
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•
•
•
A trapdoor is a door that is oriented horizontally in a floor or ceiling, often accessed via
a ladder.
Blast-proof doors are constructed to allow access to a structure but also to provide
protection from the force of explosions.
A garden door is any door that opens to a garden or backyard. It is often used
specifically for double French doors in place of a sliding glass door. In such a
configuration, it has the advantage of a very large opening for moving large objects in
and out.
A pet door (also known as a doggy door or cat flap) is an opening in a door to allow
pets to enter and exit without the main door being opened. It may be simply covered by a
rubber flap or it may be an actual door hinged on the top that the pet can push through.
Pet doors may be mounted in a sliding glass door as a new (permanent or temporary)
panel. Pet doors may be unidirectional, only allowing pets to exit. Pet doors may be
electronic, only allowing pets with a special electronic tag to enter.
[edit] Door components
the top, and perhaps a threshold at the
bottom. When a door has more than one
movable section, one of the sections may be
called a leaf. See door furniture for a
discussion of attachments to doors such as
door handles and doorknobs.
•
•
•
A diagram illustrating the components of a
panel door
[edit] Doorway
When framed in wood for snug fitting of a
door, the doorway consists of two vertical
jambs on either side, a lintel or head jamb at
•
•
Lintel - A horizontal beam above a
door that supports the wall above it.
(Also known as a header)
Jambs - The vertical posts that form
the sides of a door frame, where the
hinges are mounted, and with which
the bolt interacts.
Sill - A horizontal beam below the
door that supports the frame
Doorstop - a thin slat built inside the
frame to prevent a door from
swinging through when closed,
which might break the hinges.
Architrave - The decorative molding
that outlines a door frame. (called an
Archivolt if the door is arched).
Called door casing or brickmold in
North America.
[edit] Related hardware
See main article: Door furniture
Door furniture or hardware refers to any of the items that are attached to a door or a drawer to
enhance its functionality or appearance. This includes items such as hinges, handles, door stops,
etc.
[edit] Door construction
joint between midrail, lockrail and a
gunstock stile
Parts of a panel and or glazed door
A frame and filled door
A hollow door with one face removed
Panel doors (doors built with frame and panel construction, also called stile and rail doors):
•
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•
Stiles - Vertical boards that run the full height of a door and compose its right and left
edges. The hinges are mounted to the fixed side (known as the "hanging stile"), and the
handle, lock, bolt, and/or latch are mounted on the swinging side (known as the "latch
stile").
Rails - Horizontal boards at the top, bottom, and optionally in the middle of a door that
join the two stiles and split the door into two or more rows of panels. The "top rail" and
"bottom rail" are named for their positions. The bottom rail is also known as "kick rail".
A middle rail at the height of the bolt is known as the "lock rail", other middle rails are
commonly known as "cross rails".
Mullions - Smaller optional vertical boards that run between two rails, and split the door
into two or more columns of panels, the term is used sometimes for verticals in doors, but
more often (UK and Australia) it refers to verticals in windows.
Muntin - Optional vertical members that divide the door into smaller panels.
Panels - Large, wider boards used to fill the space between the stiles, rails, and mullions.
The panels typically fit into grooves in the other pieces, and help to keep the door rigid.
Panels may be flat, or in raised panel designs.
Lights, (UK); Lites, (US) - Pieces of glass used in place of a panel, essentially giving the
door a window.
Plank and batten doors, (an older design consisting primarily of vertical slats):
•
•
Planks - Vertical boards that extend the full height of the door, and are placed side by
side filling the door's width.
Battens - Smaller slats that extend horizontally across the door which the planks are
affixed to. The battens hold the planks together. Sometimes a long diagonal slat or two
are also implemented to prevent the door from skewing. On some doors, especially
antique ones, the battens are replaced with iron bars that are often built into the hinges as
extensions of the door-side plates.
Ledged and braced doors Consists of vertical tongue and grooved boards held together with
battens and diagonal braces.
Frame and filled door Consists of a solid timber frame, filled on one face, face with Tongue
and Grooved boards. Quite often used externally with the boards on the weather face.
Flush doors (many modern doors, including most interior doors):
•
•
•
Stiles and rails - As above, but usually smaller. They form the outside edges of the door.
Core material: Material within the door used simply to fill space, provide rigidity and
reduce druminess.
o Hollow-core - Often consists of a lattice or honeycomb made of corrugated
cardboard, or thin wooden slats. Can also be built with staggered wooden blocks.
Hollow-core flush doors are commonly used as interior doors.
 Lock block - A solid block of wood mounted within a hollow-core flush
door near the bolt to provide a solid and stable location for mounting the
door's hardware.
o Stave-core - Consists of wooden slats stacked upon one another in a manner
similar to a plank & batten door (though the slats are usually thinner) or the
wooden-block hollow-core (except that the space is entirely filled).
o Solid-core - Can consist of low-density particle board or foam used to completely
fill the space within the door. Solid-core flush doors (especially foam-core ones)
are commonly used as exterior doors because they provide more insulation and
strength.
Skin - The front and back faces of the door are then covered with wood veneer, thin
plywood, sheet metal, fiberglass, or vinyl. The wooden materials are usually layered with
the grain alternating direction between layers to prevent warping. Fiberglass and metalfaced doors are sometimes given a layer of cellulose so that they may be stained to look
like real wood.
Moulded doors
•
•
•
Stiles and rails - As above, but usually smaller. They form the outside edges of the door.
Core material: Material within the door used simply to fill space, provide rigidity and
reduce druminess.
o Hollow-core - Often consists of a lattice or honeycomb made of corrugated
cardboard, or thin wooden slats. Can also be built with staggered wooden blocks.
Hollow-core flush doors are commonly used as interior doors.
 Lock block - A solid block of wood mounted within a hollow-core flush
door near the bolt to provide a solid and stable location for mounting the
door's hardware.
o Stave-core - Consists of wooden slats stacked upon one another in a manner
similar to a plank & batten door (though the slats are usually thinner) or the
wooden-block hollow-core (except that the space is entirely filled).
o Solid-core - Can consist of low-density particle board or foam used to completely
fill the space within the door. Solid-core flush doors (especially foam-core ones)
are commonly used as exterior doors because they provide more insulation and
strength.
Skin - The front and back faces of the door are covered with HDF / MDF skins.
Door swing directions diagram.
•
Left hand hinge (LHH): If the
hinges are on the left and the door
opens in, it's a left hand door. You
push the door with your left hand.
•
Right hand hinge (RHH): If the
hinges are on the right and the door
opens in, it's a right hand door. You
push the door with your right hand.
•
Left hand reverse (LHR): Standing
in the house, the hinges are on the
right, knob of left, pushing the door
to the outside (outswing)
Right hand reverse (RHR):
Standing in the house, the hinges are
on the left, knob of right, pushing the
door to the outside (outswing)
Door swings
Door swings, or handing, are always
determined from the secure side of the door
(ie. the side you use the key on, outside to
inside, or public to private).
•
Sizing: A standard US door size 36" x 80" (0.91 m x 2.03 m).
Note: In Australia, this is different. The fridge rule applies (you can't stand in a fridge, the door
always opens towards you) - If the hinges are on the left then its a left hand (or left hung) door. If
the hinges are on the right then its a right hand (or right hung) door. See the Australian Standards
for Installation of Timber Doorsets, AS 1909-1984 pg 6.
[edit] History
An old door, Kashan, Iran
The earliest records are those represented in
the paintings of the Egyptian tombs, in
which they are shown as single or double
doors, each in a single piece of wood. In
Egypt, where the climate is intensely dry,
there would be no fear of their warping, but
in other countries it would be necessary to
frame them, which according to Vitruvius
(iv. 6.) was done with stiles (sea/si) and rails
(see: Frame and panel): the spaces enclosed
being filled with panels (tympana) let into
grooves made in the stiles and rails.
The stiles were the vertical boards, one of which, tenoned or hinged, is known as the hanging
stile, the other as the middle or meeting stile. The horizontal cross pieces are the top rail, bottom
rail, and middle or intermediate rails. The most ancient doors were in timber, those made for
King Solomon's temple being in olive wood (I Kings vi. 31-35), which were carved and overlaid
with gold. The doors dwelt upon in Homer would appear to have been cased in silver or brass.
Besides Olive wood, elm, cedar, oak and cypress were used.
All ancient doors were hung by pivots at the
top and bottom of the hanging stile which
worked in sockets in the lintel and sill, the
latter being always in some hard stone such
as basalt or granite. Those found at Nippur
by Dr. Hilprecht, dating from 2000 B.C.
were in dolerite. The tenons of the gates at
Balawat were sheathed with bronze (now in
the British Museum).
Stone door, Hampi, India
These doors or gates were hung in two leaves, each about 8 ft 4 in (2.5 m) wide and 27 ft
(8.2 m). high; they were encased with bronze bands or strips, 10 in. high, covered with repouss
decoration of figures, etc. The wood doors would seem to have been about 3 in. thick, but the
hanging stile was over 14 inches (360 mm) diameter. Other sheathings of various sizes in bronze
have been found, which proves this to have been the universal method adopted to protect the
wood pivots. In the Hauran in Syria, where timber is scarce the doors were made in stone, and
one measuring 5 ft 4 in (1.6 m) by 2 ft 7 in (0.79 m) is in the British Museum; the band on the
meeting stile shows that it was one of the leaves of a double door. At Kuffeir near Bostra in
Syria, Burckhardt found stone doors, 9 to 10 ft (3.0 m). high, being the entrance doors of the
town. In Etruria many stone doors are referred to by Dennis.
Roman folding doors at Pompeii (1st
century AD).
The ancient Greek and Roman doors were
either single doors, double doors, sliding
doors or folding doors, in the last case the
leaves were hinged and folded back. In
Eumachia, is a painting of a door with three
leaves. In the tomb of Theron at Agrigentum
there is a single four-panel door carved in
stone. In the Blundell collection is a basrelief of a temple with double doors, each
leaf with five panels. Among existing
examples, the bronze doors in the church of
SS. Cosmas and Damiano, in Rome, are
important examples of Roman metal work of
the best period; they are in two leaves, each
with two panels, and are framed in bronze.
Those of the Pantheon are similar in design,
with narrow horizontal panels in addition, at
the top, bottom and middle. Two other
bronze doors of the Roman period are in the
Lateran Basilica.
Heron of Alexandria created the earliest known automatic door in the 1st century AD during the
era of Roman Egypt.[2] The first foot-sensor-activated automatic door was made in China during
the reign of Emperor Yang of Sui (r. 604–618), who had one installed for his royal library.[2] The
first automatic gate operators were later created in 1206 by the Arabic inventor, Al-Jazari.[3]
The doors of the church of the Nativity at Bethlehem (6th century) are covered with plates of
bronze, cut out in patterns: those of Hagia Sophia at Constantinople, of the 8th and 9th century,
are wrought in bronze, and the west doors of the cathedral of Aix-la-Chapelle (9th century), of
similar manufacture, were probably brought from Constantinople, as also some of those in St.
Marks, Venice.
the following are the finest: in Sant Andrea,
Amalfi (1060); Salerno (1099); Canosa
(1111); Troia, two doors (1119 and 1124);
Ravello (1179), by Barisano of Trani, who
also made doors for Trani cathedral; and in
Monreale and Pisa cathedrals, by Bonano of
Pisa. In all these cases the hanging stile had
pivots at the top and bottom. The exact
period when the hinge was substituted is not
quite known, but the change apparently
brought about another method of
strengthening and decorating doors, viz,
with wrought-iron bands of infinite varieties
of design. As a rule three bands from which
the ornamental work springs constitute the
hinges, which have rings outside the hanging
Ornate door. Roman wall painting in the
stiles fitting on to vertical tenons run into the
Villa Boscoreale, Italy (1st century AD).
masonry or wooden frame. There is an early
example of the 12th century in Lincoln; in
Of the 11th and 12th centuries there are
France the metal work of the doors of Notre
numerous examples of bronze doors, the
Dame at Paris is perhaps the most beautiful
earliest being one at Hildesheim, Germany
in execution, but examples are endless
(1015). Of others in South Italy and Sicily,
throughout France and England.
Returning to Italy, the most celebrated doors are those of the Battistero di San Giovanni
(Florence), which together with the door frames are all in bronze, the borders of the latter being
perhaps the most remarkable: the modeling of the figures, birds and foliage of the south
doorway, by Andrea Pisano (1330), and of the east doorway by Ghiberti (1425-1452), are of
great beauty; in the north door (1402-1424) Ghiberti adopted the same scheme of design for the
paneling and figure subjects in them as Andrea Pisano, but in the east door the rectangular panels
are all filled, with bas-reliefs, in which Scripture subjects are illustrated with innumerable
figures, these being probably the gates of Paradise of which Michelangelo speaks.
An old door, Isfahan, Iran
The doors of the mosques in Cairo were of
two kinds; those which, externally, were
cased with sheets of bronze or iron, cut out
in decorative patterns, and incised or inlaid,
with bosses in relief; and those in wood,
which were framed with interlaced designs
of the square and diamond, this latter
description of work being Coptic in its
origin. The doors of the palace at Palermo,
which were made by Saracenic workmen for
the Normans, are fine examples and in good
preservation. A somewhat similar decorative
class of door to these latter is found in
Verona, where the edges of the stiles and
rails are beveled and notched.
In the Renaissance period the Italian doors are quite simple, their architects trusting more to the
doorways for effect; but in France and Germany the contrary is the case, the doors being
elaborately carved, especially in the Louis XIV and Louis XV periods, and sometimes with
architectural features such as columns and entablatures with pediment and niches, the doorway
being in plain masonry. While in Italy the tendency was to give scale by increasing the number
of panels, in France the contrary seems to have been the rule; and one of the great doors at
Fontainebleau, which is in two leaves, is entirely carried out as if consisting of one great panel
only.
The earliest Renaissance doors in France are those of the cathedral of St. Sauveur at Aix (1503).
In the lower panels there are figures 3 ft (0.91 m). high in Gothic niches, and in the upper panels
a double range of niches with figures about 2 ft (0.61 m). high with canopies over them, all
carved in cedar. The south door of Beauvais Cathedral is in some respects the finest in France;
the upper panels are carved in high relief with figure subjects and canopies over them. The doors
of the church at Gisors (1575) are carved with figures in niches subdivided by classic pilasters
superimposed. In St. Maclou at Rouen are three magnificently carved doors; those by Jean
Goujon have figures in niches on each side, and others in a group of great beauty in the center.
The other doors, probably about forty to fifty years later, are enriched with bas-reliefs,
landscapes, figures and elaborate interlaced borders.
In England in the 17th century the door panels were raised with bolection or projecting moldings,
sometimes richly carved, round them; in the 18th century the moldings worked on the stiles and
rails were carved with the egg and tongue ornament.
•
The oldest door in England can be found in Westminster Abbey and dates from 1050.[4]
[edit] See also
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Janus,
Roman
god of
doors
Access
badge
Access
control
Alarm
Alarm
manageme
nt
Bank vault
Biometrics
Burglar
alarm
Castle
Cat flap
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Category:
Car doors
Category:
Security
companies
Closedcircuit
television
Common
Access
Card
Computer
security
Credential
Door safety
Door
security
Electronic
lock
Fortificatio
n
•
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•
•
•
•
•
•
•
ID Card
IP video
surveillance
Keycards
Locksmithin
g
Lock picking
Logical
security
Magnetic
stripe card
Optical
turnstile
Photo
identification
Physical
Security
Professional
•
•
•
•
•
•
•
•
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Prison
Proximity
card
Razor
wire
Roller
shutter
Safe
Safecracking
Security
Security
engineeri
ng
Security
lighting
Security
policy
•
•
•
•
Smart card
Surveillanc
e
Swipe card
Wiegand
Mousetrap
From Wikipedia, the free encyclopedia
(Redirected from Mouse trap) Jump to: navigation, search
For other uses, see Mousetrap (disambiguation).
It has been suggested that Rat trap be merged into this article or section. (Discuss)
A mouse caught in a mousetrap.
A mousetrap is a specialized type of animal
trap designed primarily to catch mice;
however, it may also trap other small
animals. Mousetraps are usually (though not
necessarily) set in an indoor location where
there is a suspected infestation of rodents.
There are various types of mousetrap, each
with its own advantages and disadvantages.
Larger traps are designed to catch other
species of animals; such as rats, squirrels,
other small rodents, or other animal.
[edit] Mouse trap designs
[edit] Spring-loaded bar mousetrap
Mousetrap, mouse, bait (chocolate)
A baited and primed spring-loaded bar
mousetrap
The first mouse trap was invented by William C. Hooker of Abingdon Illinois, who received US
patent 528671 for his design in 1894.[1] James Henry Atkinson, a British inventor who in 1897
invented a prototype called the "Little Nipper", probably had seen the Hooker trap in the shops or
in "advertisements" and used it as the basis of his model.[2]
The traditional type was invented by Sir Hiram Stevens Maxim (who also invented the Maxim
gun). It is a simple device with a heavily spring-loaded bar and a trip to release it.
Stereotypically, cheese is placed on the trip as bait. Other food such as oats, chocolate, bread,
meat, butter and peanut butter are also effective. The spring-loaded bar swings down rapidly and
with great force when anything, usually a mouse or a rat, touches the trip. The design is such that
the mouse's neck or spinal cord will be broken, or its ribs or skull crushed, by the force of the
bar. Rats can easily escape from a mousetrap, so a larger version is used for them. Newer spring
mouse traps have a plastic extended trigger made to look like a piece of Swiss cheese that is the
color of American cheese. This is not intended to attract the mouse, but is to provide a larger
surface area for the trigger mechanism and provides reservoirs for bait to be applied, such as
peanut butter. [3]
John Mast of Lititz, Pennsylvania obtained an American patent for a similar snap-action device
in 1899.[4]
Some modern plastic designs have the advantages that the trap can be set by the pressure of a
single finger on a tab and that a dead mouse can be removed from the trap without touching the
corpse.
Spring-loaded mousetraps are capable of inflicting severe injuries to people if they are
inadvertantly or purposefully caught in the trap. Actor Perry Caravello sued Jackass star Johnny
Knoxville after Caravello was injured by placing his genitals in a spring-loaded mousetrap for a
publicity stunt.[5]
[edit] Mouth mousetrap
This lightweight mousetrap consists of a set
of plastic jaws operated by a coiled spring
and triggering mechanism inside the jaws,
where the bait is held. The trigger snaps the
jaws shut, which can kill many rodents.[6]
A mouth-type mousetrap.
[edit] Electric mousetrap
This more recent type of mousetrap delivers a lethal dose of electricity when the rodent
completes the circuit by contacting two electrodes located either at the entrance or between the
entrance and the bait. The electrodes are housed in an insulated or plastic box to prevent
accidental injury to humans and pets. They can be designed for single-catch domestic use or
large multiple-catch commercial use. See U.S. Patent 4,250,655 and U.S. Patent 4,780,985
[edit] Live-catching mousetraps
A live-catch mousetrap. Uninjured mice can
be released.
Other trap designs catch mice alive so that
they can be released into the wild. It is
important to release the mouse promptly – as
mice can die from stress or dehydration –
and at some distance, as mice have a strong
homing instinct. Survival after release is not
guaranteed, since house mice will tend to
seek out human buildings, where they might
encounter lethal mousetraps or may be eaten
by predators. In the wild, house mice are
very poor competitors, and cannot survive
away from human settlements in areas
where other small mammals, such as wood
mice, are present.[7]
[edit] Glue traps
A mouse stuck in a glue trap. A mouse can
be removed from a glue trap by pouring
vegetable oil over it.
Glue traps made using natural or synthetic
adhesive applied to cardboard, plastic trays
or similar material. Bait can be placed in the
center or a scent may be added to the
adhesive by the manufacturer. Glue traps are
used primarily for rodent control indoors.
Glue traps are not effective outdoors due to
environmental conditions (moisture, dust)
which quickly render the adhesive
ineffective. Glue strip or glue tray devices
trap the mouse in the sticky glue; users can
free the mice from the glue by applying
vegetable oil.[8] These types of trap are
effective and non-toxic to humans.
However, death is much slower than with the traditional type trap[9], which has prompted animal
activists and welfare organisations such as PETA and the RSPCA to oppose the use of glue traps.
Many mice eventually die from exposure, dehydration, starvation, suffocation, or predation, or
they are killed by people when the trap is checked. Others die from injuries or blood loss as they
try to chew through their own limbs in an attempt to escape. In some jurisdictions there have
been proposals to ban glue traps, or to legally restrict their use.[10]. Other jurisdictions have
banned their use.[11]
In Ireland it is illegal to import, possess, sell or offer for sale unauthorized traps, including glue
traps. This law, the Wildlife (Amendment) Act was passed in 2000[12]
[edit] Bucket trap
The bucket trap is another method to trap mice.[13] A ramp leads to the rim of a container holding
some water or other liquid such as antifreeze.
The mouse is attracted to the top of the container and, by various means and baits, it enters the
water. Being unable to get out, it drowns. The suffering of the mouse can be shortened to a small
extent by adding a surfactant, such as washing detergent, to the water.
The variations are many with some being single catch and some multi-catch. Some can also be
used for live catching of mice.
[edit] Inert gas mousetrap
The RADAR mousetrap, invented by Rentokil Pest Control, kills trapped mice or other rodents
with carbon dioxide, then notifies the user by e-mail so that the trap can be quickly emptied and
reset[14]. Rentokil claims that the trap is painless and also reduces future mouse deaths by
pinpointing the exact location of the trap and how many animals are caught so that their access
can be controlled by sealing access holes. PETA has recognized this product as an "animal
friendly achievement" [15].
[edit] Alternatives
This section does not cite any references or sources.
Please help improve this section by adding citations to reliable sources. Unverifiable material may be
challenged and removed. (December 2007)
Strychnine-soaked grain pellets were a common substitute for mousetraps for some time;
currently they are rarely used because of the toxicity of the chemical, the inherent danger to
children and pets, and the likelihood that the poisoned animal will die inside a wall or other
inaccessible area where its carcass will be difficult to remove.
[edit] Similar devices
Similar ranges of traps are sized to trap other animal species; for example, rat traps are larger
than mousetraps, and squirrel traps are larger still. A squirrel trap is a metal box-shaped device
that is designed to catch squirrels and other similar-sized animals. The device works by drawing
the animals by bait that is placed inside. Upon touch, it forces both sides closed, thereby
trapping, but not killing the animal. The animal can then be released or killed at the trapper's
discretion.
[edit] Mousetraps in literature
Reference to a mouse trap is made as early as the 1800s by Alexandre Dumas, père in his book
The Three Musketeers. Chapter ten is titled "A Mousetrap of the Seventeenth Century". In this
case, rather than referring to a literal mouse trap, the author describes a police or guard tactic that
involves laying in wait in the residence of someone who they have arrested without public
knowledge and then grabbing, interviewing, and likely arresting anyone who comes to the
residence. In the voice of a narrator, the author confesses to having no idea how the term became
attached to this tactic.
Ralph Waldo Emerson is credited with the oft-quoted remark in favor of innovation: "Build a
better mousetrap, and the world will beat a path to your door." In the June 1912 issue of The
Philistine, Hubbard admits that his kabojolism (a neologism coined by Hubbard to describe what
a writer, "would have said if he had happened to think of [it]") was "a mousetrap that caught a lot
of literary mice intent on orphic cheese."[16]
Mousetraps are a staple of slapstick comedy and animated cartoons such as Tom and Jerry, in
which people commonly sit on the trap or have their fingers caught in the device.