The UK Marine Accident Investigation Branch recently release a very thorough investigation into a 2021 lifeboat accident that was fortunately non-fatal.
On many vessels the inspection and maintenance of lifeboats and davits is left to inexperienced Third Mates who have no formal engineering training. Personally I think this is really bad practice. Davits and lifeboats can be complicated bits of equipment, if possible it should be experienced people who have formal engineering training who do the inspection and maintenance.
Shore based companies that look after lifeboats never hire Deck Officers to work for them, they hire engineers to work for them. So it makes no sense that Deck Officers who have no formal engineering training do it when ships have dedicated engineers who have lots of formal training.
The port side lifeboat of RRS Sir David Attenborough fell into the sea because the
remote control system did not operate in the correct sequence and control of the
davit was lost during the launching process. This happened because the winch
brake operating arm hydraulic interlock cylinder piston rod was corroded and had
not reset after the previous lowering of the lifeboat. [2.3]
The piston rod was manufactured from hardened chrome alloy steel designed to
resist wear but not, specifically, to resist corrosion in a marine environment.
The sad fact is davits are inherently simple devices but trying to make them all things to all people all the time just doesn’t work sooner or later it must be admitted that in order to save the greatest amount of people one man must “take one for the team” and release the brake from the ship, then hopefully climb down a pilot ladder, otherwise everyone else is at risk.
As always a picture says 1000 words! I hope someone mentioned to the salesman of the davit that this was a bad thing that maintenance couldn’t really correct. Nobody (Deck or Engine) can check every bearing, pin and hydraulic ram all the time and the boats are designed to lower rain or shine day or night we all have enough on our plates just trying to keep the ships in a state where we don’t need the Lifeboats!
I agree about it not being a deck/engine issue. More of a manufacture issue. The highest profit is usually to construct a device to meet the minimum requirements.
Life boat davits should be built with as close to zero maintenance in mind as possible.
But almost every time an individual with the skill, training, or knowledge to recognize a threat resulting from a design “mistake” can prevent a less than desirable outcome.
The incident took place within a couple of weeks of the handover taking place and even though the vessel had the luxury of extra personnel over and above the manning of a normal vessel it is easy to see how the corrosion passed unnoticed.
The design fault as I see it is a hydraulic ram that in its normal position is fully extended. Even if it was chromed it would still be susceptible to corrosion.
