https://en.wikipedia.org/wiki/Rail_profile
http://www.atlantictrack.com/The%20Source%20Book.pdf
I would say 140 lb rail about 7 5/16 tall. 7.3125"/48 = 0.152" rail
Steve
Code 145 measures just under 7" in O scale. I don't know about the actual height of UP's rail, but I understand it was about 130 lb. on the mainline at that time. Seven inches seems like it should be pretty close.
Tom
Building O scale diorama. Hand laying track. What is the code size that is most prototypical of the UP track of the 1940's. Thanks, saints