These loaders for transfer of cargo containers or semitrailers to and from railway cars etc. have parallel swinging links vertically connecting the load-spreader support end of the lift arm with the end of the arm which is mounted to a pivot. The links are free to swing back when the loadspreader engages a vehicle to cushion and carry the load-spreader aligned with the vehicle for transfer across the chord of a transfer arc. A weight extends the links out at the bottom to extend the loadspreader to swing back through vertical for least change in elevation. The load arm is supported on wheels to run on the cam track at or near the same elevation that is mounted to swing up and down on the mount about the pivot, so the cam track wheels run on a substantially uniform radius from the pivot. The inner end of the arm extends up to support the top ends of the swinging links which depend to support the outer end of the arm or vice versa. The loader for transfer of semitrailers or containers is further provided with an improved underreaching loadspreader which when being moved under the trailer is extended lengthwise the trailer by an engagement with the side edge of the semitrailer to reach the lift pads on the far side of the semitrailer. Swinging links also apply to parallel rotating-arms loaders and those having overhead loadspreaders.