Mechanical Aids

HOIST, POWER-DRIVEN ("HARPER")
FOR USE WITH 4/5 TON STORES-CARRYING LORRY

Application
The device is designed for lilting manhole frames and covers, small cable drums, loading coils, cases and casks, poles and similar stores not exceeding 15cwt. in weight.

General description
The hoist consists of a jib-crane of 15cwt. maximum capacity operated through a power take-off unit from the vehicle engine. A telescopic jack is fitted to the chassis to take the load from the springs of the vehicle when the crane is in use.

The jib of the hoist has an outreach of 6ft. from the nearest side of the vehicle. Beneath the foot of the jib is a built-in hand-operated winch for controlling the luffing cable to position the jib at the required angle.

A load is lifted on a single fall of cable wound onto the drum of a power-driven winch by means of a single lever to raise or lower the load. In the middle position of the lever an automatic brake holds the load. The jib is slewed manually. When not in use the head of the jib rests in a bracket attached to the side of the vehicle.

The power-driven winch contains about 50ft. of cable which can be detached from the jib and used for hauling heavy cable drums of up to 2tons in weight up the skid boards and on to the vehicle. In this case the cable is fed through a snatch block connected to an eyebolt affixed near the centre of the front pole bolster.

Capital cost of modification
Approx. £400

Remarks
This device is experimental and if successful will be fitted to new vehicles but not to existing ones.

Last revised: May 23, 2023