by Allen Hazen
BobLI has posted a question about oversize tank cars: the "rail whale" tested in the 1960s, etc. I have assumed that these were banned by the FRA because of concerns about the amount of toxic/flammable/explosive liquid that could be spilled if a single car of this size ruptured (that would be my GUESS answer to his question), but if someone can give a DOCUMENTED answer, that would be great!
But the topic brings something else to mind. Back in the steam era, the Virginian railroad had a fleet of six-axle coal cars. Why has this not been imitated? Four-axle cars in unit trains from the Western coal fields are pushing the limits of axle-load permissible with normal-size wheels and rails made from ordinary steel. There are obvious economies in loading as much in a single car as possible: running fewer cars saves on capital costs (fewer cars, so fewer sets of brakes, fewer truck center plates, fewer couplers etc etc etc). Why hasn't someone built a fleet of six-axle (so, maybe, 180=ton capacity!) coal cars for unit train use? Maybe a NEW power plant could buy them: one which, since it was having to build a new car-dumper anyway, could get one that could accommodate the bigger cars.
Possibilities that come to mind include:
---For some reason 3-axle trucks cost a lot more than one and a half times what standard 2-axle trucks cost
---Current 4-axle cars are bumping up against some OTHER size limiting factor (structural strength of center sills?)
---You can't get anybody to lend you money to buy coal cars unless they are of a type the Equipment Trust holder can readily sell to other operators if you default
---Sheer institutional conservatism
Anybody out there know something? VGN "battleship" cars certainly made coal trains more interesting visually!
But the topic brings something else to mind. Back in the steam era, the Virginian railroad had a fleet of six-axle coal cars. Why has this not been imitated? Four-axle cars in unit trains from the Western coal fields are pushing the limits of axle-load permissible with normal-size wheels and rails made from ordinary steel. There are obvious economies in loading as much in a single car as possible: running fewer cars saves on capital costs (fewer cars, so fewer sets of brakes, fewer truck center plates, fewer couplers etc etc etc). Why hasn't someone built a fleet of six-axle (so, maybe, 180=ton capacity!) coal cars for unit train use? Maybe a NEW power plant could buy them: one which, since it was having to build a new car-dumper anyway, could get one that could accommodate the bigger cars.
Possibilities that come to mind include:
---For some reason 3-axle trucks cost a lot more than one and a half times what standard 2-axle trucks cost
---Current 4-axle cars are bumping up against some OTHER size limiting factor (structural strength of center sills?)
---You can't get anybody to lend you money to buy coal cars unless they are of a type the Equipment Trust holder can readily sell to other operators if you default
---Sheer institutional conservatism
Anybody out there know something? VGN "battleship" cars certainly made coal trains more interesting visually!