Abstract: A semi-trailer and its releasable coupler for use in rail transportation of intermodal containers and other adaptable cargo. That capability is met by structuring a centered longitudinal beam to the cargo deck and fitting it with the releasable coupler of this invention, permitting the trailer to be one of an infinite number of like trailers joined end to end as a train, the flexibility and longitudinal strength gained through the beam/coupler assembly. Ease of releasing and engaging a trailer from or to the train is made practical by this coupler and the front end supports, the latter having ability to raise and lower the front section of the trailer and separating the coupler segments.

Abstract: A freight handling system particularly adapted to transfer palletized loads from one side of a freight dock to another. There is an endless closed loop conveyor comprising an endless chain defining a closed loop path, along which are unidirectional rollers. At spaced locations along the conveying path, there are a number of transfer stations each having a plurality of multidirectional rollers, in the form of casters, which permit pallet loads to be moved onto and from the conveying path. A plurality of pushing devices, particularly adapted for use in the present invention, are mounted to the chain at regularly spaced locations. Each pushing device comprises a push arm which in its operative position has an upwardly and rearwardly moderately sloped push surface which engages a palletized load at a transfer station to move it along the conveying path over the rollers.