Modeling Steel
The Steel Making Process
Brendan Brosnan
To benefit from “Steel Track” of clinics being presented at the Cincinnati 2005 NMRA convention you need a basic understanding of the process of making steel. Some steps in this process have not changed much since the industrial revolution, while other aspects have come and gone as the technology of "best practice” has evolved. In this clinic I will attempt to show how the different buildings kits offered by Walthers fit into the process. Remember you don’t have to model the complete mill complex if space or modeling skills are limited. As an example you can model the Basic Oxygen Furnace (BOF) and have the blast furnace and rolling mills as “beyond the layout” or painted “background” buildings.
How Steel is Made
The process of making steel starts at the Blast Furnace where the three ingredients, iron ore, limestone and coke are combined in precise ratios to form iron (not yet steel). The limestone helps separate impurities from the iron that is now a liquid. During the heat the iron, being heavier, settles to the bottom and slag floats to the top. When the tap hole is opened the slag flows out first and is diverted to slag cars or out of the casthouse and allowed to pool on the ground in what is called a slag pit.
The diagram below shows the critical parts of a blast furnace, except for the stoves. The stoves are the tall tank looking structures that preheat the air before it is blown into the furnace (thus the origin of the name “blast furnace”), acting like the blacksmith’s bellows. The location of these components can be in any configuration as long as the sequence of the components is maintained and it can be piped in a cost-effective manner.
Iron is a very brittle and needs further processing to become steel. Up until the 50’s this was accomplished in the open-hearth furnace, replaced by the Basic Oxygen Furnace (BOF) starting in the 60”s. After the blast furnace is tapped, the hot iron is transported to the BOF where it is transferred into a ladle and poured into the BOF vessel. Oxygen is blown into the liquid to increase the temperature. Once the liquid has been heated sufficiently, a charge of scrap steel is added and more oxygen is blown into the mixture. Depending on the desired properties different additives will be carefully measured and poured into the heat to improve the properties of the steel.
When the BOF first replaced the open-hearth process the finished liquid steel was removed from the furnace and poured into molds to form ingots, the same process that had been used with the open-hearths. Once the steel had cooled enough to retain its shape, the ingots were removed from the molds. Before they could be formed into slabs or billets they had to be reheated, a very energy-wasting step.
In the late 70’s the US mills began experimenting with a process called continuous casting. Prior to the spike in energy costs, the capital expenditure required to install a caster was difficult to justify for an industry that was short of cash. However wage and energy inflation soon forced mills to adapt or close. This continuous casting process works a lot like a soft ice cream machine allowing liquid steel to pour from a tub like vat called a tundish though a narrow nozzle into the caster. As it cooled it forms a continuous bar and is forced out the other end of the caster. Further cooling is applied and the slab gains structural integrity. As it exits the caster it has cooled enough to retain its shape and is cut to length, usually about 20ft. by a torch. The slabs are then moved to the storage yard or directly to the rolling mills. The continuous caster eliminated the need to reheat the ingots, and is a much more efficient process.
Mini-mills make steel from scrap steel or scrap substitutes in an electric arc furnace (EAF). Electric furnace steel, like integrated steel, is then cast into the semi-finished forms. Because an integrated process takes more steps (i.e., coke batteries, blast furnaces), is more capital intensive, and traditionally requires more man-hours per ton, the minimills have used their cost advantage to take share away from the integrate steel mill+blast furnace operations. However, as the price of the raw materials that go into an electric furnace, i.e. scrap, has increased, the cost advantage of the minimills has diminished. The integrate mills, too, have brought their costs down at the same time. Generally, if scrap is above $160-170 per ton, the minimill cost advantage disappears.
To operate a minimill, an electric arc furnace is usually filled or charged at the top with scrap steel. A typical 200,000-300,000 ton per year electric furnace would be 25-30 feet in diameter. A large electric current is sent to the furnace via carbon graphite electrodes. Between the electrodes an electric arc forms, creating enough heat (3,500 degrees F) to melt the scrap. The electrodes, which look like thick, short telephone poles, are pure carbon. As the electric arc melts the scrap, the steel’s chemistry is periodically tested, and with the addition of iron or alloys into the mix, new steel is made with the desired specifications. As in the integrated process, a ladle met station might be employed after the EAF process for final chemistry trimming before the steel heads to a caster.
Additional Modeling Resources
Yahoo Steel Group ( is the best source of modeling support for the steel mill enthusiasts that I have experienced. The folks on this list are a mix of modelers, industrial history buffs and retired and active mill employees. Somebody on this list can answer just about any question you have. The file section has spreadsheets to calculate the number of car movements needed in a typical shift, captions for the BecherBlast Furnace book as well a links to steel and steel hauling RR websites.
Next in importance is the NMRA “Railroad Industries Modeling SIG”.
This SIG concentrates on developing a deeper understanding of the history and operations of the industries that are served by the railroads. This information helps to understand and replicate prototypical operation on model railroads and to construct prototypically accurate models. The SIG publishes a quarterly newsletter, Lineside. For further information consult:
- RRIMSIG Membership Chairman
P O Box 508 - Gasport, NY 14067-00508
While the SIG is not exclusively related to Steel, a majority of the members are steel mill modelers.
For detailed HO scale plans of various mill structures including blast furnaces, open-hearth furnaces, BOF’s and Hulett unloaders, contact MIKE RABBITT, 565 FOREST ROAD, WAYNE, PA 19087
Brandon Wehe produces excellent resin castings of charging ladles, scrap buckets etc. and a variety of steel related decals including the Union RR, contact Brandon Wehe, 11787 US Highway 150,Orion, IL 61273-9225.
This list would not be complete without mention of the now out of print “The History, Making and Modeling of Steel” by Dean Freytag.
Older Editions of United States Steel’s book “The Making, Shaping and Treating of Steel” can be found on eBay at reasonable prices. It is filled with photos, drawings and plans.. Older editions detail the open-hearth process but BOF’s were non existent, so select the edition that fits your modeling era.
I have available several photo CD’s of various steel mills, equipment and rolling stock. Each CD has between 150 and 500 jpeg scans of slides taken at mills, most taken on company property with permission. Contact me at or Brendan Brosnan 889 Willcrest Dr. Chattanooga, TN 37405.
Articles in the Model Railroad Press
Weathering steel mill cars
Model Railroader, December 2002 page 112
Alkem Steel
In Celebration of 10 years of N-Scale 1989-1999
Article also published in N Scale, March/April 1998, page 28
Article also published in N Scale, May/June 1998, page 34
Modeling steel mill sites and operations
Railmodel Journal, October 2000 page 45
Layout Tour: Bethlehem Steel at Sparrows Point, Maryland on NTRAK modules
Railmodel Journal, October 2000 page 45
Heavy industry in a small space
Model Railroader, January 1999 page 140
Three ways to model an interesting steel mill railroad
Columbia Steel's Prairie Works
Model Railroader, March 1999 page 104
Steel and nickel production plants are the heart of this HO layout
A Big-Time Revenue Producer For Your S Scale Layout
S Gaugian, July/August 1998 page 22
Building a Steel Mill, Part 1
N Scale, March/April 1998 page 28
Building a Steel Mill, Part 2
N Scale, May/June 1998 page 34
An incredible model built from the Walthers HO kits
Calypso Yard: Heavy Industry
Railmodel Journal, March 1997 page 33
Modeling heavy industry on a portable layout
Model a steel mill radio controlled locomotive
Railroad Model Craftsman, November 1997 page 82
Haulin' steel on the Ohio Southern
Model Railroader, April 1996 page 82
A steel mill heavy hauler - kitbash a specialized vehicle
Railroad Model Craftsman, February 1996 page 66
Scratchbuild A Steel Mill From Pikestuff Parts
Railmodel Journal, August 1994 page 10
Modeling a bottle car to carry molten steel
Railroad Model Craftsman, November 1994 page 90
Ingot molds and buggies - a steel mill basic
Railroad Model Craftsman, January 1992 page 82
Addison Steel Co.
NMRA Bulletin, March 1989 page 37
Painting and weathering hot metal cars
Railroad Model Craftsman, July 1989 page 73
Detailing steel mill switchers
Railroad Model Craftsman, November 1989 page 80
Steel Mill Narrow Gauge
Short & Narrow Rails, #22 page 5
Severna Park's steel mill - largest HO structure?
Model Railroader, November 1984 page 109
A Chance of a Lifetime - Building a Steel Mill's Model Railroad
NMRA Bulletin, August 1980 page 38
Monessen Southwestern Railway
NMRA Bulletin, September 1977 page 8
Steel Mill railroad, 9x12 ctr op
Model Railroader, November 1950 page 12
Photo CD Order Form
The photo CD & DVD’s include mill buildings, blast furnaces, BOF’s, ore bridge, locomotives, specialized cars and various ancillary equipment. Most were taken on company property with permission. Coke and Steel Vol. 1 & 2 has over 500 images including Weirton, Lukins, Johnstown, Mingo Jct. Acme steel & Coke, Chicago, LTV Cleveland, Sparrows Point and others. The Rouge photos were taken on three visits and contain over 250 images. The National Steel photo has approximately 140 images taken on Zug Island before the USS merger, and the McLouth/ Ferrous Processors, a scrap steel dealer, CD has over 100 images including detail shots from the bell platform. The 2004 SIG and Steel Modelers Meet CD, includes Lackawanna Coke and other industries and photos of the model displays and Ken McKorey’s steel layout . Lake Michigan Mills is 350 photos of Indiana Harbor (ISG), Burns Harbor and USS Gary. Ohio River Mills with 500 photos of Mt States Carbon coke plant, Wheeling Pitt. and a detailed visit to Weirton including a climb to the top of BF. A DVD containing all of the above. new titles: The 2008 SIG Meet has Riverdale BOF, USS Gary and Indiana Harbor west, ex LTV Huletts and other industries in the Calumet region. Acme Video is a 1997 tour of the coke plant & blast furnace including Calumet River LTV Huletts in operation. Also includes Weirton, Lukins and Bar Tech. 2 hr run time.
CD # / Description / Price / Quantity / AmountCS1 / Coke & Steel Vol 1 & 2 / SOLD / OUT
RS1 / Rouge Steel / $10.00
NS1 / National Steel / $10.00
MC1 / McLouth & Ferrous / $10.00
SIG / 2004 SIG & Modelers Meet / $10.00
LM / Lake Michigan Mills / $15.00
OH1 / Ohio River Mills / $15.00
DVD1 / All of the above on one DVD ($80 value) / $50.00
SIG-08 / ArcelorMittal, USS, Hulett and others / $15.00
Video 1 /
Acme Steel Coke Works & Blast Furnace
/ $20.00POSTAGE *
Total amount of payment enclosed
* POSTAGE and Handling is $2.00 for the first CD/DVD and $.50 each additional CD
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Brendan Brosnan
889 Willcrest Dr.
Chattanooga, TN 37405
ALL ORDERS MUST INCLUDE THE FOLLOWING SIGNED AGREEMENT
I hereby certify that the images contained on the photo CD are for my personal use in modeling or educational research. I will not cause these images to be published and/or post them on any public website for viewing or downloading without written permission.
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