Deck Crane Failure Sheds Light on Lack of Maintenance
If lifting equipment is not well maintained even a relatively small weight in relation to the crane’s safe working load (SWL) can cause a failure. Recently, a crane gave way because greasing of a relatively inaccessible part of the crane had been neglected.
It does not take much for a crane with hidden defects to give way. In the case incident described (anonymously) in The Nautical Institute’s Mars Reports, the lift was only five per cent of the crane’s capacity. A transcript of what happened:
A tanker had loaded cargo and the crew were preparing to depart. The pilot was on board and the gangway (eight metres long and weighing 250 kilogrammes) was to be secured for sea. It was hooked onto the deck crane, which had an SWL of 5000 kilogrammes. It was lifted away from the ship’s side, then brought slowly down to the stowed position.
Just before the gangway was in the stowed position, the topping cylinder broke away from the crane jib and the crane arm gave way. The gangway fell onto the deck, but as all crew had been standing clear there were no injuries and the gangway was only slightly damaged.
The company investigation found that the hydraulic cylinder eye attachment fitting had not been properly maintained. The fitting was situated in a relatively inaccessible part of the crane and greasing of this part had been neglected.
Actions Taken by the Company and Manufacturer
In response to this accident, the greasing point of the cylinder eye attachment has been fitted with a fixed conduit so the operator can perform greasing directly from the safety of a nearby platform, as seen below.
Additionally, the job card was updated. Instead of a generic maintenance description, the new card indicates specific greasing points to help crew to identify all maintenance areas. Editor of the Mars Reports, Captain Paul Drouin FNI, adds that ‘Equipment maintenance job cards should be as specific as possible to help crew identify
all areas of work that need to be covered.’
Finally, the manufacturer reviewed the design of cylinder eye bushings. Subsequent cranes will have bushings made of synthetic material instead of metal to reduce the risk of the steel pin seizing.
This accident was covered in the Mars Reports, originally published as Mars 201953, that are part of Report Number 322. A selection of this Report has also been published in SWZ|Maritime’s September issue. The Mars Reports are also published on SWZ|Maritime’s website to help prevent maritime accidents.
More reports are needed to keep the scheme interesting and informative. All reports are read only by the Mars coordinator and are treated in the strictest confidence. To submit a report, please use the Mars report form.