General guidelines about steam era tank car practices?

Jim Betz


So I want to focus on tank cars - but realize that I don't
have a lot of knowledge about them.

Is there a 'reference' that I can read/study/find online?

I'm interested in answering questions such as:

How common are the 2 and 3 dome cars? Weren't these cars
'obsoleted' fairly early compared to the single domes that
were built in the same era? How late would they have run?

How early did the companies such as GATX, URTX, etc. come
into the picture and how long after they showed up on the
scene would you still expect to see considerable numbers of
cars lettered for the oil companies?

When did frameless cars start to be seen? (I think these
cars are primarily "post the STMFC era".)

It is quite common to see earlier style cars (with frame)
lettered for a specific RR ... such as ATSF or GN or whatever.
I follow the GN closely and as far as I know the tank cars
that were lettered for the GN were in captive service and
used for hauling products that were used by/consumed by the
GN itself (as in fuel, etc.). Is that a 'standard practice'
or did some roads use tank cars for "general service" (as
opposed to home road only service)?

Is there any guideline in terms of size that can be used to
easily differentiate steam era -vs- later cars? As in "most
of the tank cars in the steam era were 10k or less"? And is
there any kind of 'start date' for larger cars such as the
16k and 20k tanks.
How about in terms of car length? I don't remember seeing
pics of tank cars longer than 40ft in steam era pics.
- Jim

P.S. I -do- intend to "go to my books" and scan the pics for
examples of tank cars. What I'm looking for are a few
'rules' (albeit "fuzzy rules").

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