Don't forget that this period overlaps with the heyday of the RailWhales.
http://www.railgoat.railfan.net/railwhales/index.htm
DSchmitt A book that looks like would help answer your question Vol 1 digital reprint https://morningsunbooks.com/products/tank-car-color-guide-volume-1-cars-with-full-center-sills-digital-reprint Vol 2 hard copy https://morningsunbooks.com/products/tank-car-color-guide-vol-2
A book that looks like would help answer your question
Vol 1 digital reprint
https://morningsunbooks.com/products/tank-car-color-guide-volume-1-cars-with-full-center-sills-digital-reprint
Vol 2 hard copy
https://morningsunbooks.com/products/tank-car-color-guide-vol-2
I have both and they are HIGHLY recommended to anyone who is this interested in tank cars. In general I was surprised by how early the center sill-less cars began to dominate. Your era would definitely feature the more "modern" style. For the most part the information in those books is in the captions as there is relatively little pure text as such.
Another good source of information, much more summary than the two Morning Sun books by James Kincaid, but more text oriented, is Jeff Wilson's Kalmbach book, The Model Railroader's Guide to Freight Cars. It has a chapter on tank cars with good photos and information. Frequently seen at swap meets. If you can find a copy (it was not intended for ralfans or modelers but rail industry people) is the GATX Tank Car Manual. Mine is dated 1966 (second edition) which is perfect for my modeling era. I got it at a railroad collectible swap meet, not a model train swap meet.
Dave Nelson
There are some publications that may provide more of what you are looking for than the ORER. Most companies in the ORER list their cars by ICC classification which in many cases does not affect the external appearance of the car. Also most companies list the capacites of their cars in pounds instead of gallons. In other words, a car with a capacity of 100000 pounds, could have a capacity of 4000 gallons or 11000 gallons depending on what it was used for. The ORER does not give information as to who leased cars with ACFX, GATX, or UTLX etc. It is a reporting mark oriented listing of cars under that mark, which may be of some use in modeling. There are some other books that may be more informative to a modeler. "American Car and Foundry-1899-1999" and "Tank Cars-American Car & Foundry Company, 1865-1955" by Edward S. Kaminski, Signature Press, give a history and insight into the manufacture of tankcars built by ACF along with hundreds of photographs of cars built by ACF for operation under private as well as SHPX and ACFX reporting marks. The tankcar book also has a selection of very fine drawing as well as the photographs. Don't let the 1955 in the title mislead you. Many pre-war cars lasted well into the 1970s and tank cars designs didn't begin to change radically until the late 1950s. Since the tank was considered a separate entity from the frame, as long as the tank could pass the required ICC testing , it could be married to a new frame and remain in service. Also, as companies merged or otherwise combined or sold off their cars, it was not uncommon for the cars of one builder to operate under the reporting marks of another such as UTLX under SHPX, GATX under ACFX,etc. More information on the cars of General American can be found in the "Tank Car Manual" published by General American Corporation (the GATX people). This is a prototype publication that contains a lot of information on the types of cars GATX can provide a prospective customer or user. There are line drawings of various types of cars as well as car components and systems. At one time these books could be ordered from GATX but in today's world, I don't know. The time period you are interested in would covered by the second edition (June 1966) and the third edition (April 1972). I found my second edition on Amazon so, check there and, e-Bay. Morning Sun has published a two volume set devoted to tankcars, divided by cars with, and without conventional underframes. Morning Sun also covers a lot of tank cars in their five book set titled "X-Cars" which is devoted to private owner cars of all types. There is alot of information available on a very interesting subject.
c
Here's a power point thing about Union Tank cars. UTLX. It shows the progression of the design and shape of tank cars, through the years.
http://www.utlx.com/pdf/TankCarHistory.pdf
Mike.
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While I am waiting for my copys of the ORER's to arrive, and for the ease of others searching the subject, can anyone help out with what style tank cars (all commodities) were common and new in the late 60s early 70s? Many hours of Google searching is not returning much in the way of relevant answers, mostly only more confusion.