Some flatcar loads while relativly small were so heavy they exceded the axle loading limit for a standard (2 bogie) flatcar.
Several Railroads modified flatcars by replacing the normal 2 bogies with two bolsters with bogies at each end which then attached to the underside of the car body in the same manner as the original single bogie. This reduces the axle loading by almost half. This is the body section of an empty car.
Use Consist 'Railcar 8 axle FM KRL 500' <kuid:633834:101012>
or
Assemble this car in Surveyor by placing the body section on the track then select the bolster (kuid2:210518:6501:1) and place them half way between the center
of the body and each end. When properly assembled there will onl;y be 1 red and 1 green arrow and the car will move as a unit.