steel ingots article

Modeling Steel Ingots and Molds
An important part of steel mill modeling is understanding the use of ingots; their history, what they
look like, the different sizes, how they are moved and processed. This article will attempt to answer
some of these questions.
Ingots have been used since the 1870's to move steel from the furnace to the rolling mill. Originally
small batches of steel were made using the crucible process and an ingot was made by pouring the
contents of several crucibles into a mold. Each of the crucibles weighed about 70 lbs. As you can see
from the early engraving it was labor intensive, hot, dangerous and inexact. Differences in composition
and temperature of each crucible could render an ingot unusable.
J.Glaab Collection
It wasn't until the advent of the Bessemer process that ingot production became more organized and
controlled. Molds were mounted on rail cars and the metal poured into them (teemed) without the
dangers inherent to the crucible process. The molten metal was poured from the furnace into a ladle and
transported to the “teeming” station via a very heavy stiff leg crane. As technology improved the stiff
leg crane was replaced with an overhead crane. Ingots were rarely allowed to cool and were worked
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(rolled) into shapes while the ingot was in a plastic state. Firm enough to be self-supporting the outer
portion was semi-solid while the center was near liquid. Since the process of making ingots and rolling
ingots rarely matched perfectly, ingots would have to be held in a “soaking pit” at a temperature that
would allow them to be rolled.
Hagley Collection
Here you can clearly see the ladle mounted on the stiff leg crane platform and the Bessemer converter
in the background. The stopper plug in the bottom of the ladle would have to be replaced every four to
five heats. One odd thing about this photo is that it appears that the workman has dropped the handle
that operates the stopper plug!
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J.Glaab Collection
This unusual, but very compact arrangement makes the process of teeming about as efficient as it could
be, at least at the turn of the 20th Century. The open hearth furnace pours directly into the ladle and
directly below are the ingots. Pretty clever! You can tell that this is a publicity or construction photo.
No one in their right mind would be down in the ingot pit if the furnace was working! Notice the stiff
leg crane on the right that was probably used before the moving ladle.
J. Glaab Collection
Here you can see a more modern teeming operation. The teeming platform is some distance away from
the steel making operation. The ladle is bigger and is supported by an overhead crane. This is part of
an open hearth furnace plant typical of what you might expect to see in the 1930s thru 1950s.
INGOT MOLDS
Ingot molds are made of cast iron. Two of the larger manufacturers of ingot molds were Gathman and
Valley Mold. They provided molds for most of the major steel makers.
The most typical ingot mold was the small end up, top fill, mold which sat on a separate stool. These
came in a variety of sizes as specified by the steel producer. Every mold was fitted with two
projections on the side (ears) that could be grasped by the lifting crane to lift the mold from the ingot.
Some molds were ribbed some were smooth. Molds were not lined with refractory material for steel
doesn't stick to cast iron. (Most of the time)
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Hagley Collection
Here you can see the workman scraping scale off the inside of the mold. The lifting ears are clearly
visible on the foreground mold. These ears are grasped by the stripper crane to lift the mold off the
ingot. If the mold is not properly cleaned it may cause the ingot to stick in the mold. “Stickers”, as
they are called, can sometimes be removed by using the ram on the stripper crane to push downward on
the ingot while in the jaws of the stripper crane.
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J. Glaab Collection
Some stickers stay stuck! I photographed this one in 2006 being used to block a roadway at Sparrows
Point. Steel worker folklore states that every steel mill has at least one “sticker” somewhere out in the
back lot.
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J.Glaab Collection
This photo was taken in a small park in Duquesne, PA. The molds are the size typically used to make
rail. The car is narrow gauge and of very simple construction. From the late 1800's thru the early part
of the 20th Century narrow gauge was used for handling ingots and scrap.
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C.Pravlik collection
These strange looking ingot molds were used at J&L's Aliquippa works. Each narrow gauge (36”) car
holds four; small end down, big end up molds with hot tops. When these molds were teemed the
molten metal was poured through the attached hot top into the big end of the mold. Since molten steel
is a bubbling hot liquid, the hot top served to capture the frothy part of the steel thus allowing the ingot
to be more uniform in composition. Note the idler car between to loco and first ingot car.
Extracting the ingot from the mold was done by pulling the ingot upward from the mold. First the hot
top is removed. The ingot mold is then held in place and the stripper crane lifts the ingot clear of the
mold and lowers it into the soaking pit.
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J. Glaab Collection
Another variation of ingot molds are the small end up, bottom fill type. The post sticking up in the
middle of the car is referred to as the “flag” and is the pour spout for filling the molds. Molten metal
flows down through the flag and through channels in the bottom of the car and up into the bottom of
the molds. And yes, this is a very labor intensive process for the flag and the gutters in the bottom
have to be removed and rebuilt with each use. I counted eight different types of molds.
Do we still use Ingots?
Yes indeed! Lukens, Timkin, Allegheny Ludlum and a few others still use ingots as opposed to slab or
strand casting. Ingots are used for specialty steel which is made in electric furnaces. Lukens makes
armor plate and Timkin makes bearings, not the sort of steel you need for car fenders or washing
machines.
Today virtually all ingot cars are standard gauge. Narrow gauge probably was being phased out by the
late 1950's but some operations lasted into the 1990's.
Modeling Ingots, Molds and RR operations.
Fortunately today's steel mill modeler can select from a variety of commercial models of ingots, molds
and cars. As you might expect the variety is best in HO scale. But how do you choose the best models
for your mill?
If you model steel mills from the “Transition Era” of railroading you have several choices based largely
on your mills final products. If you model a rail mill, you will want smaller molds and ingots. If you
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model armor plate or plate for ships you can use larger molds. As a general rule the ingots are sized to
work best with the size of the rolling machinery. There is no point in rolling rail in a 96” plate mill, nor
can you roll heavy plate in a mill sized to make rail.
Commercially made ingot and mold models
To get started here is a listing of the commercially made models and a description of their type and
size. There may be other manufacturers but I am not aware of them. I have only listed those products
that are presently commercially available.
Ingots & Molds
HO Scale
Mfgr
Rix
ST&D
ST&D
ST&D
ST&D
ST&D
PCSHOPS
PCSHOPS
PCSHOPS
PCSHOPS
Description
Ingot Mold (no size specified)
Ingot for Rix Mold
CMA 11+ Ton Ingot Mold
CMA 11+ Ton Corrugated Ingot Mold
CMA 11+ Ton Ingot**
CMA 11+ Ton Corrugated Ingot**
Rail Ingot Mold
Rail Ingot ***
Small Ingot Mold
Small Ingot ***
Size
4'10” x 2'10 'x 8'11”
N/A
2'4” x 3'1” x 8'2'
2'4” x 3'1” x 8'2'
2'4” x 3'1” x 8'2'
2'4” x 3'1” x 8'2'
1'8” x 1'10' x 7'
1'8” x 1'10' x 7'
2'6” x 1'4' x 5'5”
2'6” x 1'4' x 5'5”
Capacity
121.9 cu. ft.
N/A
58.6 cu. ft.
58.6 cu. ft.
58.6 cu. ft.
58.6 cu. ft.
21.4 co. ft.
21.4 co. ft.
18 cu.ft.
18 cu.ft.
Weight*
30 tons
N/A
14.4 tons
14.4 tons
14.4 tons
14.4 tons
5.3 tons
5.3 tons
4.4 tons
4.4 tons
N Scale
PCSHOPS
PCSHOPS
KenRay
Ingot Mold
Ingot***
Hot ingot
4'7” x 2'5” x 10'
4'7” x 2'5” x 10'
N/A
109 cu. Ft.
109 cu. Ft.
N/A
26.9 tons
26.9 tons
N/A
*The density of steel varies from 483 to 503 lbs. cu. ft.
for these calculation I used the average of 493 lbs. cu. ft.
** These can be obtained as hot or cold. The hot
ingots are orange opaque plastic. The cold ingots
are gray plastic.
*** These ingots are made of orange translucent
acrylic.
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Here are the ubiquitous HO Scale Rix Ingot Molds and cars. These have been the standard for the
steel hobbyist for many years. Simple in construction, easy to build and modify, they track well and
have been used by hundreds of model railroaders for many years. This is the type of mold and car that
would look right in a heavy plate mill from the 1930's through the 1950's. It is however a large ingot
(30 tons) and is perhaps too large to be compatible with the Walthers rolling mill.
This is the Peach Creek Shops “Youngstown” cast steel Ingot car with ingots for rail or bar
manufacture. This car is made to run on narrow gauge track and can be fitted for Hon30 or Hon3.
Many steel mill modelers use N scale trucks and track which works out nicely to be Hon30. Tilig
makes a wide variety of HO/HOn30 track components that are just about perfect for narrow gauge steel
mill operations.
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If you are modeling an HO scale contemporary electric melt shop and you want to use ingots you can
use the very nice ST&D large bottom pour car pictured on the left or you can do as Aaron Dupont did
and kit-bash a Rix ingot buggy using four PCS ingots and some Plastruct tubing and parts.
J.Glaab Collection
One of the nice things about modeling an ingot operation is the possibility of using special lighting
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effects. This was taken on my old “Magarac Steel & Iron” layout and shows hot ingots being pushed
into the soaking pit building where the molds are being stripped off. The ingots were made from
orange Acrylic plastic sheet (available from Plastruct) and lighted with a 1.5volt miniature Christmas
tree bulb. The cars do not move. Trying to get lighted ingots to function on a moving car was just too
frustrating. Blinking ingots DO spoil the effect!
J. Glaab Collection
Here is another view of the soaking pit showing the lighted ingots and the glow coming from an open
cover on the soaking pit. Shelby Corbin was responsible for the concept and construction of this
structure. I made the ingots by laminating two pieces of orange acrylic plastic and then cutting out the
ingots. I couldn't buy acrylic sheet thick enough to make ingots that properly filled the mold so
laminating was necessary.
My first attempt at making a lighted ingot looked pretty rough so I spent some time sanding and
polishing the sides to a mirror smooth finish believing that this would make the light diffuse better.
When we put a light inside, it looked like a nicely polished piece of Acrylic plastic! Shelby then took
my highly polished ingot , roughed up the surface with 80 grit sandpaper, painted it Polyscale reefer
orange, dry brushed the edges with grimy black, put the light back in, and voila! We had a very
respectable glowing ingot!
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J.Glaab Collection
Modelers tend to visualize ingots as smooth, brightly glowing masses of steel with nice neat surfaces
and edges. Not so. When an ingot comes out of the soaking pit it looks pretty rough. There is a lot of
scale that has to be removed. The above photo shows and ingot that has been removed from the
soaking pit and placed on the carriage that will move it and flip it onto the feed table for the first stage
of the rolling process. Blasts of high pressure water removed most of the scale which was reclaimed
and put back in the furnace.
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If you want to see a very good video of what happens to an ingot after it is removed from the mold go
to:
https://www.youtube.com/watch?v=VjN3fQWjRQQ
This is a video of the Wierton Blooming Mill in operation and very well done.
At the 2014 SMMM in Bethlehem, Pa we had two excellent models of blooming/rolling mills on
display. David Moltrup produced this very nice, condensed version to fit in the available space on his
layout. It captures all of the essential elements of a blooming mill and uses a mixture of commercially
available and scratch built parts.
Jim Burnside has a bit more space for his rolling mill and started with the Walthers kit and several
additional rolling stands. A mixture of commercial and scratch built parts, some of them made on a 3D
printer, were used to make this very fine model. It was good enough to win the Dean Freytag Award.
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John Glaab
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