WW2 Austin 5th Wheel Coupling

[N.O.S.]

This is the Austin 5th Wheel Coupling fitted to the Autocar U7144T.

 

As well as the usual front/aft pivot (as on a modern artic coupling), it has lateral pivot typical of off-road tractor units. Seems a good idea. However, note the cross shaft is cranked, which allows a pendulum-effect forward / aft movement of 4 inches.

 

Oooh....now why did they have to do this? :argh:

 

Surely this will lead to a see-saw effect when pulling a trailer, a bit like pulling a tanker with no baffles :confused::confused::confused:

 

p.s. the pipe wrench is for a bit of cosmetic straightening of the baseplate.

[Bodge Deep]

is it damped?

Or is it to releive the the strain on the transmission brake/brakes when parking against the sloshing effect of unbaffled or poorly baffled tanker trailers? Liquid could slosh back n forth for a while after parking i s'pose?