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The international factory crane magazine
HOIST
Giant gantry crane
North America
Galvanising
Shipyards
UK
www.hoistmagazine.com
March 2010 Issue 89
ON SITE
River dance
A gantry crane is being used to lift
and carry large precast concrete shells
that will be set in the Ohio River as
part of the construction of the
Olmsted Dam, Illinois, USA.
T
he gantry crane, worth USD9.5 million, not including
assembly, foundations or lifting equipment, can lift a
maximum of 5,100 US tons, is wheel-mounted and
travels on steel rails. It is used to lift and carry various
lifting frames as well as positioning them for installation on
the precast shells. It has the capability to move the lifting
frames perpendicular to the crane rails.
“The Olmsted Dam gantry crane is the largest gantry
crane of its kind in the world,” according to the US Army
Corps of Engineers, Olmsted Resident Office, which is
overseeing the project.
The crane, designed and supplied by Ederer LLC, a
division of PAR Systems, Seattle, is self-contained,
operating off a crane-mounted 300kW Caterpillar diesel
generator. The top of the gantry supports stands for 12
strand jacks, the primary lifting mechanism to raise and
lower the concrete shells.
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www.hoistmagazine.com March 2010
ON SITE
Powered by 12 7HP electric motors, the crane is
designed such that the two upper most beams, known
as strand jack beams, can be hydraulically adjusted to
conform to various lifting frame configurations.
Unloaded, the gantry will travel at 20ft per minute;
loaded, it will travel at 10ft per minute.
A total of 64 36in diameter steel wheels are utilised for
the movement of the crane. There are four rails, two each
side, with a total runway length of 1,200ft.
Other structural components of the gantry crane
include eight travel truck assemblies, eight vertical legs
and twelve box beams. Approximately 5,000 bolts and
welding holds these components together.
Overall dimensions of the crane are 100ft-long from
travel truck number one to travel truck number four, 160ftwide from outside of leg to outside of leg, and 140ft-high
from ground level to the top of the strand jacks. This gives
interior dimensions of 100 x 130ft.
Pre-erection on the ground of the girders, beams and
leg assemblies took approximately one year, while lifting
and erection of the main structural members took two
months to complete.
Two Manitowoc 4600 crawler cranes were used to lift
and place the components. The heaviest lift in this
process was a girder, weighing 428,268lbs which put
each of the crawler cranes at 95% of their maximum
capacity, says the US Army Corps of Engineers.
March 2010 www.hoistmagazine.com
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