Psht, I once did a rail that was much to long to even measure. I had to create my own distance scale to even give it perspective and that rail was 65 fruugtons.
in the extra raw footy in SH6 they have some one doing it, and they slide the whole thing, then it looks like they catch an edge or something as theyr coming off
42 meters is about 137 feet. and im pretty sure the keystone rail is 150, math may be a little different in canada but im pretty sure thats only a difference of 13 feet, which is about 4 meters.