Re: Ribbed Back Wheels

Paul Hillman

Sorry Tony about not telling the strengthening part about the ribbed wheels as I remember discussed. But John Sykes input about their AAR 1968 cut-off date in interchange would mean that in 1950 (my modeling period) there must have been a pretty good mix of ribbed & flat-back wheels.
Thanks all, Paul Hillman

----- Original Message -----
Sent: Monday, May 05, 2014 12:22 AM
Subject: Re: [STMFC] Ribbed Back Wheels


Paul Hillman wrote:

A few days ago there was a discussion about the purpose of ribbed back wheels, and the answer was the "ribs" were there for cooling during forming - casting of the iron wheels. But, when did we see ribbed-backed wheels disappear from the rails? Apparently the "ribs" went away with the use of steel in wheel making.

    Not sure what discussion you reference. But it is simply NOT true that the ribs had anything to do with cooling. They are there to strengthen AND stiffen the wheel. Later analysis showed that the effect is not large, so simple wheel plate shapes have been used ever since. The casting process can be used to make either kind of wheel, whether the wheel is cast iron or cast steel, so the ribs have nothing to do with whether they are iron or steel.
     Chilled iron wheels are cast with chills at the wheel tread to improve performance of that area. That process has nothing whatever to do with ribs. Railroads realized as early as 1930 that steel wheels provided better durability, but also cost more, and moreover were often in short supply. Especially after World War II, railroads placing orders for new cars with wrought steel wheels had to accept part or all of the order with cast wheels, because production of wrought wheels could not keep up.
     My basis for this is not only my professional experience in both academic and industrial metallurgy, but my multi-year experience on the AAR Research Committee, involved in research on materials for both rail and wheels, including meetings at the AAR Research Facility near Pueblo, Colorado (now the Transportation Technology Center). Believe me, we covered wheel production and wheel materials to exhaustion.

Tony Thompson
2906 Forest Ave., Berkeley, CA 94705
(510) 540-6538; fax, (510) 540-1937;
e-mail: tony@...

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