Shown is a wrecking crane adjacent to a maintenance flat car with what appears to be spare trucks (bogies) painted orange. Did these trucks serve any special purpose? Were they possibly temporary replacements for trucks of cars damaged in derailments, like a spare tire of sorts?
Some times refered to as "shop trucks",used to get cars not "Totaled Out"(destroied) to the nearest "RIP" track or to a siding where
repairs could be done.(The cars's trucks have turned into a "parts kit" ). Using a shop truck saves on the labor needed to move
the "load" from the damaged car to another car.
This allowed the wreck site to be cleared up a little bit quicker, with only 1 train moving to a yard to clear up with the
damaged cars in tow.