Lifeboat Wires - Do You Have a Hidden Problem

A recent report published by the New Zealand Transport Investigation Commission has once again highlighted the dangers associated with plastic coating or sheathing on wire ropes. During the recovery of a lifeboat, a wire sling parted and the lifeboat fell several meters back into the water from deck level. Fortunately, in this particular case, only one of the four crew members on board the boat during the recovery was injured.

The subsequent investigation found that the lifting wire had been corroded by seawater penetrating and accumulating under the plastic sheathing. The condition of the plastic was such that it did not allow a robust examination or inspection to be completed as per manufacturer’s instructions and the vessel’s planned maintenance schedule. The existence of the plastic sheathing also prevented the application of anti-corrosive coating which is important to both protect, and prolong, a wire’s working life.

It is important that critical safety equipment, such as lifeboat launching/recovery wires, is inspected and maintained to the standards required by the International Maritime Organization Convention for the Safety of Life at Sea (SOLAS) and the vessel’s planned maintenance system.

The total encasement of steel wires in plastic sheathing when used in the marine environment has significant safety implications, especially when the wire must be regularly inspected and maintained to remain fit for purpose.

Encasing wire rope in plastic sheathing prevents the wire being lubricated, maintained and inspected and may accelerate the onset of corrosion through the retention of salt water within the core of the wire rope, ultimately resulting in the weakening and failure of a wire.

Seafarers and surveyors should not make assumptions on the condition of any wire that cannot be fully inspected, especially when used in critical safety equipment. Vessels should closely examine any wires found encased in plastic and due consideration should be given to removing and replacing this sheathing to allow a thorough inspection.

Further details on wire ropes and their uses can be found in North’s Loss Prevention Briefing which may be read here: www.nepia.com/media/246286/LP-Briefing-Ships-Wire-Ropes-and-their-Usage-April-2015.PDF

A full copy of the New Zealand Transport Investigation Commission investigation report referred to above may be read here: www.taic.org.nz/ReportsandSafetyRecs/MarineReports/tabid/87/ctl/Detail/mid/484/InvNumber/2014-202/Page/0/language/en-US/Default.aspx?SkinSrc=[G]skins%2ftaicMarine%2fskin_marine

This report may be reprinted in whole or in part without charge, providing acknowledgement is made to the Transport Accident Investigation Commission of New Zealand.