Container restraining mechanism and method

A system for holding and restraining a longitudinally extending roll-off container on a longitudinally extending truckbed along which, during inclined elevation of the bed, the container has been upwardly winched into position for carrying on the truckbed when the bed is lowered to the horizontal transport position, and, thereafter, during such inclined elevation, the container is lowered downwardly along the bed to touch the ground, the system having, in combination, means for mounting at opposite corresponding regions of longitudinal bottom edges of the container and longitudinal side edges of the bed, respective protuberances and receptacles therefor constituting interlocking teeth that longitudinally slidingly interlock as the container is winched upwardly into position and longitudinally slidingly disengage as the container is winched downwardly off the inclined bed, the locations of said regions being adjusted so that the interlocking is effected during the last distance of upward winching and the disengaging is effected during the initial distance of downward winding, wherein the protuberances are triangular and are welded to the sides of the container bottom structural longitudinal edges and wherein each triangular protuberance has a square section welded to it to assist interlocking engagement with the corresponding mating receptacle, also welded to the bed, such that when forces try to remove the container, as in an accident, the square section interlocks with the mating receptacle to prevent wedging action that would otherwise occur between the triangular protuberances and the mating receptacles.