TM 9-2320-361-10 2-30. OPERATION OF DUMP TRUCKS (Contd) Table 2-3. Weight of Material in Truck. (Contd) b. Rigging Tailgate. (1) To rig tailgate (4) for dumping and spreading operations: (a) Pass free end of chains (2) through retainers (3) and into locking slots (1). 2-142