If a piece of rail has 141lb stamped on it, then what does that mean and how is it measured? Also what is the heaviest weight rail in use today on mainline railroads? Also is there any differenece in height of the different weight rail?
Rail is measured in lbs/yard - a 3’ section of that rail would weigh 141 lbs. The heaviest rail was something like 155-156 lb rail that the PRR used. And yes, the ‘height’ the rail does vary - the reason for ‘compromise’ angle bars.
Jim
The rail will also be stamped with two letters following that number, like 141RE indicating that the rail is rolled to AREMA standards for 141lb rail. Those standards specify every dimensional detail of the rail. There will be other markings identifying the manufacturer, when it was rolled, any special heat treating, etc.
Probably the 141 RE is the heaviest weight rail in use today on mainline railroads. The PRR did indeed have 152 and later 155 lb. sections, but that was superseded by other sections - modern metallurgy made slightly smaller sections just as good or better. Specifically, the 132 and 136 lb. was installed by ConRail so long ago that I doubt that any of the 152 or 155 remains in main tracks anymore. If the track was busy enough to need the 152 or 155, it would have been worn out and replaced by now. I’m equally sure that some 152 or 155 remains on former heavy-duty branch lines - about 20 years ago I saw a branch in the Shamokin, PA area that was 152 PS, and I doubt that’s been replaced - and in yards, etc. with rail that was reclaimed from main line tracks for re-lay use in that kind of location, but not in the main lines any more. - Paul North.
Improved metallurgy and the steam-to-diesel conversion go a long way to explaining the use of relatively lighter rail. Dynamic augment from steam locomotives doesn’t occur anymore so the rail no longer has to handle that additional stress. I’ve observed 131RE to be pretty much the standard on main lines around Chicago.
115, 133,136, and 141 are by far the most commonly (almost only) rolled sections anymore. There is some new 132# rail coming into the country from Russia, but not that much…
Lehigh and PRR 155# & 157# rail is still out there in places and the 171#-172#-175#CR crane rail (with its own built in flangeway or thick beefy - webbed version) is also around in places. (There were AREMA experiments with 144# rail as heavy haul curve rail, but I think that has died off)…
I can think of a couple of places where 155# rail is welded to 90# rail which looks absolutely goofy. (doesn’t even come close to matching at the base. Somebody should have used a set of 112/115# and 131/132/136# rails to step down… then again, PC/ConRail was known for being weird, the further away you got from Philadelphia)
There is only so much you can do on a tie plate that can accomodate a 6" base dimension.
I often wonder what would happen if you used 172#CR in a heavy bolted railbound carbon frog (all machined / no inserts) or as wingrails around a cast insert, would it work better than conventional rail? …or is just too hard and too unusual to manipulate?