Incident

When hauling the net, the net crane fell into the net bin, where two men were hurt and had to be brought to the hospital.

Cause

The incident was probably caused by the loosen a locking plate secured to a shaft with three bolts, which caused the outermost joint of the crane to slide off the shaft and into the net bin, where there were two men at the time. The bolts keeping the locking plate in place have no locking/securing device. It appears that the three bolts loosened, and thus there was nothing to keep the locking plate in place.

The bolts used were of stainless steel, had a diameter of 12 mm, a thread pitch of 1.75 mm and a length of 37/33mm incl./excl. head. The incident could have been avoided through better procedures for pre-use overhaul and inspection of cranes, or if the bolts were of a type that could have been secured with wire thread locking.

Measures

The crane manufacturer informs that original bolts were used, and that similar incidents have not been reported previously. As a consequence of this incident, the crane manufacturer will now start using locking bolts to prevent such situations occurring again.

TMP 700K cranes are often used on small fishing vessels and cargo ships. Therefore, the Norwegian Maritime Authority requests that all owners of such cranes carry out an additional inspection of the bolts attaching the end plate to the crane, and also arrange for regular maintenance and inspection.

The company is obliged to establish routines for inspection and maintenance of all lifting equipment. The master shall ensure that personnel who are to operate the crane are trained as required. The training shall be documented. The crane operator has a particular responsibility for performing a pre-use inspection of the crane in accordance with the user manual.   

When a new crane is to be mounted on board, a certification requires an initial examination to be carried out by a competent person type A. This also applies when a new crane is to be mounted on an existing crane foundation.

References

Regulations of 17 January 1978 No. 4 on cargo-handling appliances in ships