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.
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:
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 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.
RailroadBookstore.com - An online railroad bookstore featuring a curated selection of new and used railroad books. Railroad pictorials, railroad history, steam locomotives, passenger trains, modern railroading. Hundreds of titles available, most at discount prices! We also have a video and children's book section.
ModelRailroadBookstore.com - An online model railroad bookstore featuring a curated selection of new and used books. Layout design, track plans, scenery and structure building, wiring, DCC, Tinplate, Toy Trains, Price Guides and more.