Interesting comments, I just measured a piece of 3 rail Gargraves track which mates to Atlas and Ross track , the rail top is .231 above the tie . This would be accurate for G scale or close.
Code 172 was used with Truscale wood road bed from the 60's .It may accommodate 3 rail flanges .
I am aware that code 148 is the most common , when measuring the rails with a caliper there is .024 difference in height . Early Atlas sectional 2 rail track was .166.
I was just curious if many 2 rail guys still use .172 rail . And yes the steel rail is often used on grades for better traction . The O scale club that was at the LA fairgrounds , used .172 as did the old Santa Fe RR at the Museum of Science and Industry in Chicago.
As many of you know , the flanges on the early Max Gray and USH trucks had larger flanges than what is offered today.
Many 3 rail modelers should use those trucks do get away from the oversize flanges when going for a more scale wheel profile and could negotiate 3 rail track brands mentioned above..
