The Shipbuilding and Ship-repairing Regulations 1960

Every winch, and every derrick with the whole of the gear accessory thereto, shall be tested with a proof load which shall not be less than the following— Safe working load Proof load Under 20 tons 25 per cent.in excess of the safe working load20–50 tons 5 tonsover 50 tons 10 per cent. In the case of a derrick with its accessory gear the proof load shall be applied as follows:— where reasonably practicable by hoisting movable weights; or in other cases by maintaining the load by means of an accurate spring or hydraulic balance or similar device for a period of not less than five minutes. Where movable test weights are used the derrick shall be swung, with the load suspended, as far as possible in both directions. Where a spring or hydraulic balance or similar device is employed it shall be sufficient if the proof load is applied with the derrick swung as far as practicable first in one direction and then in the other. In each case the derrick shall be tested at the smallest angle to the horizontal at which it will operate and this angle shall be stated in the certificate of the test.

Every crane, crab, sheer-legs, teagle, transporter or runway, with its accessory gear, shall be tested with a proof load which shall not be less than the following— Safe working load Proof load Under 20 tons 25 per cent.in excess of the safe working load20–50 tons 5 tonsover 50 tons 10 per cent. In the case of a crane having a variable radius it shall be tested with a proof load applied at the maximum and minimum working radii. At each such radius the crane shall be swung as far as possible in both directions with the corresponding proof load suspended. In the case of hydraulic cranes where, owing to the limitation of pressure it is impossible to hoist a load 25 per cent. in excess of the safe working load, it shall be sufficient to hoist the greatest possible load.

Every article of lifting gear (whether it is accessory to any lifting appliance or not) and every pulley block other than a pulley block specially constructed for use with a crane to which it is permanently attached, and every chain shall be tested with a proof load at least equal to that shown against it in the following table:— Article of gear Safe working load Proof load Chain sling Twice the safe working loadRope sling Plate clamp Ring Link Hook (other than a ramshorn hook) Shackle Swivel Eye-bolt Ramshorn hook Under 50 tons Twice the safe working load50 tons to 100 tonsSafe working loads plus 50 tonsOver 100 tons One and a half times the safe working load Pulley blocks Single sheave block Four times the safe working loadMultiple sheave block with safe working load up to and including 20 tons Twice the safe working loadMultiple sheave block with safe working load over 20 tons up to and including 40 tons 20 tons in excess of the safe working loadMultiple sheave block with safe working load over 40 tons One and a half times the safe working load Chains (other than calibrated load chains) Twice the safe working loadCalibrated load chains One and a half times the safe working load

After being tested as aforesaid, every lifting appliance with the whole of the gear accessory thereto, every article of lifting gear and every chain shall be examined, and the sheaves and the pins of the pulley blocks shall be removed for the purpose of the examination, to see that no part is injured or permanently deformed by the test.

In the case of wire ropes, a sample shall be tested to destruction.