Abstract: A system and technique for holding down and restraining a roll-off container in place as it is winched into its final position on the bed of a truck or other transport device, wherein, as the roll-off container is winched into position on the truck, a protuberance on the side of the bottom rail of the roll-off container slides into a mating interlocking cradle attached to the truck. The sliding mate can be of a cantilevered spear into a socket, or more generically, a sliding open-ended mate such as a dovetail. In the event of a crash or sudden stop, the roll-off container will thus be retained by the interlocking connection.