Lifting appliances are tested by a cargo surveyor at intervals of 5 years, or following installation or repairs.
The test could be conducted by either of two methods:
- By lifting the proof load, and swinging the load through the derrick or crane’s operating arc, as per the ship’s rigging plan. This test is known as the ‘dynamic test’ and concrete blocks of the correct weight are normally used to conduct this operation.
- The static test is carried out employing a ‘dynamometer’ secured to the lifting point of the rig and an anchored position on the deck. The proof load weight is then placed on the rig and measured by the dynamometer, to the satisfaction of the surveyor.
- It would be normal practice for the Ship’s Chief Officer to delegate this supervisory task to the duty Deck/Cargo Officer before loading or discharge operations is allowed to commence.
- In addition to the regular working checks, all lifting gear should undergo an annual inspection by a responsible person, namely the Ship’s Chief Officer.
- It is a requirement of the ISM system that lifting gear is correctly maintained and inspected at regular intervals.