The M5 bomb trailer is a 2½ ton capacity vehicle used during World War II for transporting bombs from munitions storage areas to the aircraft for loading.
The front pair of wheels are mounted on a caster assembly like a shopping cart.
After the train left, the crew would manhandle the trailer to a position under the bomber to enable the loading of the bombs.
These trailers were used extensively in World War II on air bases for the transport of bombs and other ordnance.
Others are in private Historic Military Vehicle (HMV) collectors hands around the US and the world.