Generally. Cars made before WW2 were mostly riveted together. During the forties welded cars came into fame. The length of car really did not represent the carrying capacity. And you can't overlook the multitude of types of flat cars. Well cars sometimes falls under flat car but has a big hole in it.
Pete.
PRR had a huge funeral pyre for years during the Thirties at Lucknow Shop, just north of Harriburg, where they burned now unneeded wooden cars to recover the scrap metal (Presumably by running a crane mounted electromagnet over the embers, then shoved the next victims into place)
Most of the regulation changes (no archbar trucks, steel underframe etc.) were put in place under FDR, mostly between 1934-1938. If your layout is before that, it wouldn't be an issue. Plus, it would only affect cars your railroad sent out or rec'd in interchange with another railroad. Online only cars (like cabooses) sometimes used archbar trucks into the 1960s.
One thing to keep in mind is that during the Depression, as the need for freight cars fell, railroads tended to put their oldest stuff in mothballs first. Railroads generally buy equipment as part of a trust (kinda like buying a home with a mortgage) where they take a couple of decades to pay off the expense. They'd want to keep cars like that working and earning money so they could keep the payments up, so you'd put your 1880s-90s cars aside and use your 1910s-20s equipment.
Thanks for the info both! I'm definitely no rivet counter so just having stuff that is close enough to "feel" right is good enough for me - I have enough headache with a shortline whose equipment is all rather unique, I'm not going to be super picky about the interchange equipment.
Just in general (i.e., not flat car specific), 40' cars started to be common in new car orders in the 1910's. Before that, 36' or 34' cars had been the standard for about 20 years or so.
Cars with steel underframes / center sills I believe started to be made about the same time, IIRC cars without a steel center sill were banned from interchange in the mid-1930s, about the same time as archbar trucks.
"One difference between pessimists and optimists is that while pessimists are more often right, optimists have far more fun."
I have been looking at some "cheap" and era appropriate (read: ready to run from major manufacturers) HO scale flat cars, and selecting what is appropriate for my 1931-1932 date for my prototype has been difficult - while there are good resources for when different types of box cars, I have never seen a guide for flat cars.
My main questions are:-When did 40' cars start being used? What about 50'?-When did steel framed cars start being used? Are their noteworthy differences between the different steel framed styles you see in the transition era, and are those different styles introduced at different times?
If anyone has any other resources on the flat cars of the depression era, or flat cars in general, that'd also be appreciated too!
Thanks in advance!