Somebody posted a great link on the evolution of the tank car, but I can't find it now

I thought I had saved the link, but apparently I didn't. Hope someone out there can give me this link. Thanks, Jim

 

I doubt if this is what you're looking for, but it provides a nice history of the tank car.
http://industrialscenery.blogspot.com/2018/01/tank-car-history.html

 

The one I had seen previously was great on stating years and footages on the various tank cars with lots of illustrations. The immediate question that I am trying to answer is when did 60 foot fuel tankers in general appear on the railroads? More specifically when did they appear on the Southern Pacific Railroad?

 

Don’t know what era you model but this one has SP by tank type.

http://www.railgoat.railfan.net/spcars/byclass/tank/index.htm

 

Here is an early one.