intermodal cars, what holds the trailer on?

In this case what holds the trailer on the flat car…

The same thing that holds them on while in ships and while double stacked, pins. I am not sure if the pins on that flatcar are a permenant part of the car or are removable, I have never been real interested in intermodal.

The “pins” are called IBCs, Inter Box Connectors. They are not part of the car. The car has sockets on it identical to those on the containers.

Trailers are held onto the flatcars by a locking pit underneith the trailer which slots into the fifth wheel much the same as it does on a truck, then gravity does the rest

Guess it has already beed said… pins [:p]

Thanks for the help everyone!

In the case of trailers, the trailer’s king pin holds it to the car’s fifth wheel.

In the case of containers, it’s the IBX (Interbox Connector). They lock into sockets on the containers. Cars carry similar sockets, and the IBXs are usually left in the car’s sockets, even if the car is unloaded. Some cars also have the IBXs permanently mounted on them.

Nick Brodar