Tony, of course you are correct. I didn't intend to be lazy and slip in that poor excuse, but was attempting to limit the discussion and try to keep it corralled within the bounds. I should have known the rocket scientist and metallurgist would not let it go. I spoke with Bob LeMassena for a few hours one day about this topic (if you have ever spoke to Bob about steam locomotives, you realize that this qualifies as a short talk). He explained the metal issues (and it is also in his book "Superpower in the Rockies") but he went into it further in person.

As another aside, there were a LOT of improvements that came near the end of steam that showed tremendous promise that had they been followed through might have shown tremendous leaps over then current technology. I'm sure the Pennsy foamers can chime in here. But that too is a trip off the course.

And, as another aside, yes, Richard, my understanding of the Car Construction Committee is less than decent, something that is a result of being more interested in slightly narrower and shorter cars that were running behind steam for a much longer span and having to be more conversant with certain other aspects of certain railroad in order to try to write about it.

My interests in these specific cars have to do with the possibility of finding a car "family" that might be made available for the roads that didn't have large fleets of cars liable to be targets of manufacturer (like, say the AT&SF). From your note though, it seems the approach has already been used. However, I wonder then about tank cars as that is one car type that always seems to be decried as not having proper representation in the model world due to the many variances and the uncertain prototypes so far chosen.



At 02:54 AM 9/16/2005, you wrote:

Message: 15
Date: Thu, 15 Sep 2005 21:08:21 -0700
From: Anthony Thompson <thompson@...>
Subject: Re: A point of order - war board cousins

Bob Webber said:
. . . Bob [LeMassena]

has explained the problem, bad boiler metals caused some premature
boiler issues that caused some boiler mishaps and they figured they'd
retire them rather than reboiler them."

Yes. I did a bit of research and noted the same thing. Interestingly,
NP
encountered the same thing and they did reboiler.

While we are on "metallurgy," I will comment briefly that the
steels chosen in order to go to thinner boiler shells (thus saving
weight on these big locos) yet keep high boiler pressures turned out to
be unsuitable. It was not "bad metal" but a poor choice by the
builders, who chose the alloys used. They turned out to be sensitive to
stress-corrosion cracking under the temperatures and water chemistries
used. Had this not happened at the very end of steam, it would surely
have been corrected (there are far better alloys to use), but of course
this was not to be.

Anthony Thompson
Dept. of Materials Science & Engineering
University of California, Berkeley
thompson@...

Bob Webber

On Sep 16, 2005, at 6:51 AM, Bob Webber wrote:

....However, I wonder then about
tank cars as that is one car type that always seems to be decried as
not having proper representation in the model world due to the many
variances and the uncertain prototypes so far chosen.

Actually, by ca. 1930 there were only two tank car manufacturers in the U.S., AC&F and General American, (plus one in Canada, Canadian Car & Foundry), and the two tank car designs that were being built from 1930 through WW II were the AC&F Type 27 and the GATC Type 30. These were thus de facto "standard" designs. The problem is that they were made in a variety of types (ICC-103, insulated ICC-104, insulated high pressure ICC-105, and other specialized tank designs for acids, corrosive chemicals, and such) as well as a variety of sizes, everything from 4,000 gal. to 12,500 gal. After WW II, both AC&F and GATC switched to all welded construction, though their tank car designs didn't change much in other respects.

Briefly, during WW II, there was a "war emergency" tank car design, intended to save steel, which was assigned specification USG-A and AC&F built more than 700 of them; they were essentially the 10,000 gal. tank of USRA design (never actually built during WW I but resurrected during WWII) mounted on a standard AC&F Type 27 underframe. Those cars can be modeled in HO scale with a Tichy tank on an Intermountain underframe, plus some detail modifications.

Conveniently, both AC&F and GATC mounted both 8k and 10K tanks on the same underframes, and Intermountain takes advantage of this to produce both 8K and 10K versions of the Type 27s with ICC-103 tanks, as does Life-Like in their models of the earlier AC&F Type 21s. But that's no help in modeling smaller size tank cars, of which there were many, nor multiple compartment cars which were almost all of 6K gal. or smaller capacity, nor large insulated ICC-105s used for chlorine and LPG service. So, in effect, the standardization of tank cars in that era meant that all the underframe components were the same, except that the underframes were of different lengths, while the tanks varied widely in size and type.

Richard Hendrickson