Re: Tichy tank car

Dave Parker

Sorry Tony, this is simply not true.  If you dig back into the ARA tank car specs from ca. 1920, you can find the outage tables and chart that gives the needed expansion volume for a given commodity.  With a high enough vapor pressure, and a high enough loading temperature, the required head space could easily reach 3+%, and the fix was to fill the car to less than shell- full.   A specific table for each car design told the shipper how many inches short of full-shell to fill the car for a given % expansion volume.  A simple dip stick presumably facilitated the measurement.  Examples of such tables can be found in the Standard Tank (Car) Companies books "All About Tank Cars" from 1919 and 1921.  The widely circulated 1952 UTLX summary of all of their cars also contains reference to the correct Outage Table Number for each car design and size.

As I tried to explain, Texaco apparently skirted this inconvenience by ordering Class III and IV cars with domes in excess of 3%, and even 4%, of the tank volume.  This makes modeling TCX cars something of challenge if your goal is prototypic accuracy.  None of the models really look right next to the prototypes.

Dave Parker
Riverside, CA

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