Japan P&I Club issues LP Bulletin on cranes operations and reasons for failures
The Japan P&I Club has issued Loss Prevention Bulletin on cranes to provide guidance regarding their inspections, maintenance and operation in order to prevent incidents involving damage to a crane.
Cargo handling cranes, commonly pedestal mounted jib cranes, are fitted on board most handy-size bulk carriers, most general cargo ships and some other smaller or larger bulk carriers. These cranes appear to be fairly robust units which will continue to work when only a minimum of maintenance is carried out, but, in fact, they are highly complex pieces of machinery which incorporate numerous components manufactured to very fine tolerances, all of which must function correctly throughout a working period for the crane, as a unit, to be operated as the manufacturers intended. The cranes should be properly maintained, and should be inspected at specified intervals to ensure that they operate correctly and safely. Additionally, all other equipment used in association with a crane should, likewise, be properly maintained and should be inspected as appropriate. If the equipment is not in the appropriate good condition, failures are likely to occur during cargo operations.
Any failure of any part of the crane will lead to delays in the cargo operations, and any such delay is likely to have other consequences. Additionally, the renewal of parts or the carrying out of repairs might be necessary, which is likely to be expensive and cause further delays.
The failure of a cargo handling crane is likely to involve one or more of the following:
1. Failure of a hoist or luffing wire
The result of poor maintenance of the wire leading to weakening of the wire over time or inappropriate operation of the crane and incorrect use of the wire leading to damage being sustained by the wire.
2. Failure of the structures
The result of poor maintenance of the various elements leading to weakening of the structures or incorrect use of the crane leading to damage being sustained by the structures
3. Failure of the machinery
The result of poor maintenance leading to the failure or incorrect use of the crane leading to overloading of the piece of machinery.
Inspections and Maintenance
Cranes, and other lifting appliances and their loose gear, are required to be thoroughly inspected annually, with a further thorough inspection and a proof load test every five years. Those inspections and testing are in accordance with the ship’s Flag State requirements, although it is common procedure for the classification society surveyor to carry out the required inspections and tests. Details of the surveys should be recorded in the ship’s Register of Lifting Appliances and Cargo Handling Gear.
Also, there should be on board an appropriate test certificate for all wire ropes on board; that is, for all of those in use and for all spare wire ropes. The certificates should give the date of manufacture, the material strength, the construction of the rope and the breaking load test of a sample. There should be an inventory of all wire ropes on board and records of the dates of renewal of the wires in use on all cranes.
Wire ropes, motors, electrical control systems and other pieces of machinery and equipment wear out or might be damaged during the operation of a crane. It is therefore necessary for a number of spare parts to be maintained on board at all times. The trading pattern of the ship will, to an extent, dictate what type and what number of spares will be required. If the ship is trading in very hot or very cold areas, or if the cranes are frequently used for cargo handling, the hoist wires and winch motors might not last as long as if the ship is trading in less harsh environments. For example, even ignoring misuse, the hoist wire might be heavily worn with broken wires after only two years in use if self-loading and self-discharge is a routine procedure, whereas the hoist wire of a crane on a ship which is trading between terminals with onshore loading and off-loading facilities might require renewal at only five year intervals.
Maintenance and inspections of the cranes, their wire ropes and their various pieces of machinery and equipment are essential to ensure that the operation of the crane is reliable and that there is a minimum of wear and damage
Incidents involving damage to a crane
When an incident involving one or more of the ship’s cranes occurs during cargo operations, be it major or minor in extent, the crane(s) should be immediately stopped and an investigation and inspections of the crane(s) should be started. Incidents might include failure of electrical or mechanical components, failure of a hoist or luffing wire or failure of any part of the structure of the crane, any bearings or sheaves. The incident might have been brought about by mishandling of the crane by the crane driver, by contact between the structure of the crane and another object – possibly the cargo being handled or another crane – or may be the result of an unforeseen failure of the maintenance and repair system on board.
The investigation should establish facts as follows:
- The extent of the failure and what parts of the crane(s) are involved.
- The reasons for the failure.
- The extent and nature of all repairs which are necessary
Remedial action should then be started, without delay, and the classification society should be notified. If structural repairs are carried out, or if work associated with load bearing systems is done, the crane should be re-tested with a proof load by a competent authority recognised by the Flag State, or other certifying authority on behalf of the Flag State. All broken or failed parts should be retained for future testing and examination. Records of all incidents should be kept, with details of all findings and remedial action taken. Additionally, a report, including full details, should be issued to the operators’ office.
Learn more by reading Japan P&I Club’s bulleting on Cranes
Source: Japan P&I Club
