Thanks, Ken.lower weight, sharper curves.
A few North American freight cars have have single axle trucks, in particular an articulated (iirc) COFC/TOFC (Container or Trailer On Flat Car) railcar of a few years back. Containers and trailers are normally very light and the reduced rolling friction of a single axle helps reduce fuel consumption. Haven't seen any in many years tho so I don't know if they are still around.
Norfolk Southern has a subsidiary called Triple Crown Services that still operates roadrailer trains today. These are essentially truck trailers joined together by rolling a rail wheelset under the the rear of the trailer.While we are on the subject...Anyone remember when they were hauling truck trailers by just placing a set of wheels under the trailer? Sounds unbelievable but they were depending on the aluminum frames of the trailer to push and pull the trains. Not sure how long those lasted or what became of it and would enjoy hearing any info.
Norfolk Southern has a subsidiary called Triple Crown Services that still operates roadrailer trains today. These are essentially truck trailers joined together by rolling a rail wheelset under the the rear of the trailer.
Some more photos of the equipment here:
actually they have a lower center of gravity (notice that the are much closer to the tracks) so they in theory have less chance of blowover. The biggest issue is that the trailers themselves must have very heavy duty frames to provide drawbar strength, and heavy duty frames hurt fuel mileage when used as a truck trailer.It would seem they wouldn't stay on the rails especially if they were running in high wind where those trailers would blow over easy. Apparently they are successful as I have never read about any incidents yet.
They weren't just rough, but also lightly built with lots of curves. Early American railroads didn't have the same level of financial backing that their British and European counterparts had, which meant that the track and bridges were often lightly built and followed the lay of the land with lots of curves and very few cuts, fills, or tunnels. That sort of construction pretty much meant that freight and passenger cars with two or even three axle trucks were sorely needed if the railroads in question expected to stay in business.Lots of smaller American MoW equipment had two axles as well. Tie carts, tie cranes, ballast spreaders, spike zappers, etc.
Correct me if I'm wrong, but I thought that American equipment evolved into having two trucks under car because, in the early stages of the railroad, American tracks were quite rough compared to Britain's tracks. I always hear about how crews hated bobber cabooses because they gave such a rough ride (thus the term "bobber").
I just returned from 2 months in Ohio working on a movie and was able to spend a day at both Fostoria and Berea, as well as Cleveland were we stayed. I saw many roadrailers. Looks like a smart way to move trailers and the train seemed very stable.I had no idea they were still using those. I will have to make a visit out East to check that out. It's hard to believe those were ever a success. It would seem they wouldn't stay on the rails especially if they were running in high wind where those trailers would blow over easy. Apparently they are successful as I have never read about any incidents yet.
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