Nosed Truck

The recovery of a nosed truck using a wrecker truck may require only a towing operation. Some situations may require all three of the capabilities (winching,

Figure 5-6.-Simple winch operation (direct pull).

Figure _5-7.-Mechanical advantage and change of direction (winching).

Figure 5-8.-Winching by change of direction

lifting, and towing) of the trucks to complete the recovery.

Figure 5-8 shows a mechanically disabled 2 1/2-ton truck nosed off a narrow road in such a way that the wrecker cannot be positioned directly behind the vehicle. You may notice that the winch cable is not running in a direct straight line with the winch. On a normal winch, this angle causes the wire rope to wind off the side (flange) of the winch drum; however, the wrecker winch has a level winding device that offsets the difference. Other vehicles with winches do not have this device.

Overturned Truck

To upright an overturned truck with a wrecker truck, you should use a sling method of attachent, because a pulling force applied to only one point of the frame can result in a bent frame. A sling lifting attachent is made up of either two utility chains or two 1-inch fiber ropes. The sling ends are attached to the front and rear lifting devices on the high side of the overturned truck. Then the winch cable is attached to the center of the sling. A holding force is required to prevent the overturned vehicle from crashing onto its wheels. The holding force

Figure 5-9.-Righting an overturned truck.

Figure 5-10.-Highway tow.

could be another vehicle, the wrecker boom, or a rope block and tackle with manpower.

The attachment for the holding force is a holding sling attached to the same points on the overturned truck as the pulling sling. The holding sling is then attached to the holding force with wire rope, rope, or chain, making sure the holding force is attached to the center of the sling. If a holding vehicle is not available, use the wrecker boom to hold the load, as shown in figure 5-9.

Apply power gradually to the winch until the overturned truck is past the vertical position. Then lower the truck on its wheels with the hoist winch, rather than booming out with the crane.

NOTE: Maximum use of the boom jacks and outriggers should be employed when this method is used.

Towing

A wrecker truck is capable of towing vehicles in several ways. The proper procedures and safety guidelines for towing are important factors in preventing damage to vehicles and injury to personnel. The basic procedures and guidelines for highway towing and cross-country towing are as follows: HIGHWAY TOW.- Attach the tow bar to the lifting shackle eyes of the disabled vehicle and the wrecker truck tow pintle. All wheels of the towed vehicle should be on the ground. With the tow bar, a driver is not required in the towed vehicle. (See fig. 5-10.)

CROSS-COUNTRY TOW.- Over rough terrain, across-country tow controls the towed vehicle well. The procedure for rigging for the cross-country tow is as follows: (1) attach a chain lifting sling or the hoisting bar between the front lifting shackles of the truck; (2) attach a tow chain from the wrecker tow pintle to the lifting shackles of the disabled truck; (3) place the hoist hook block in the lifting sling approximately 12 inches off the ground; (4) extend the boom to remove the slack from the tow chain, and keep the towed vehicle from ramming into the rear of the wrecker truck; and (5) support the boom with the shipper braces to prevent impact loads on the crane mechanisms. (See fig. 5-11.)

If the front end of the vehicle is damaged, use cross-country towing even though the disabled vehicle is being towed on the highway. Use the tow bar instead of a tow chain.