Warn­ing after safety har­ness tether fail­ure

The Marine Ac­ci­dent In­ves­ti­ga­tion Branch ad­vises clip­ping on away from deck fit­tings and other equip­ment

Yachting Monthly - - NEWS -

Sailors who use jack­stays and clip­ping sys­tems aboard are be­ing urged to make sure their tether hook can’t be­come en­tan­gled in deck fit­tings and other equip­ment.

The ad­vice comes fol­low­ing the death of Clip­per Round the World par­tic­i­pant Si­mon Speirs, who went over­board in the South­ern Ocean dur­ing a head­sail change on Novem­ber 18, 2017.

The Marine Ac­ci­dent In­ves­ti­ga­tion Branch (MAIB) has is­sued the safety bul­letin as it con­tin­ues to ex­am­ine the cir­cum­stances sur­round­ing the death of the 60-year-old CV30 Great Bri­tain crewmem­ber.

He was using a three-point web­bing tether at­tached to the in­te­gral har­ness of his life­jacket that al­lowed him to clip on to the boat’s jack­stays with a short or long tether.

The MAIB’S ini­tial find­ings re­veal the hook on the end of his tether that was clipped to a jack­line be­came caught un­der a deck cleat, re­sult­ing in a lat­eral load­ing that was suf­fi­cient to cause the hook to dis­tort and even­tu­ally re­lease.

The har­ness tether was cer­ti­fied un­der ISO 12401 (small craft – deck safety har­ness and safety line – safety re­quire­ments and test meth­ods). The MAIB said the tests to meet this in­ter­na­tional stan­dard as­sumed the tether and its hooks would be loaded lon­gi­tu­di­nally rather than lat­er­ally.

It stated Speirs’ tether hook was of a con­ven­tional de­sign and qual­ity, and was com­monly used by man­u­fac­tur­ers of safety har­nesses and teth­ers that were cer­ti­fied un­der ISO 12401.

‘When loaded lon­gi­tu­di­nally, the tether can with­stand a load of over 1 tonne. How­ever, when loaded lat­er­ally, a tether hook will de­form at much less load. It is im­por­tant that tether hooks re­main clear of ob­struc­tions and are free to ro­tate to align the load lon­gi­tu­di­nally,’ ad­vised the MAIB.

‘To pre­vent the strength of a safety har­ness tether be­com­ing com­pro­mised in ser­vice due to lat­eral load­ing on the tether hook, the method used to an­chor the end of the tether to the ves­sel should be ar­ranged to en­sure that the tether hook can­not be­come en­tan­gled with deck fit­tings or other equip­ment,’ it added. Ad­ven­ture train­ing skip­per Rachael Sprot from Ru­bi­con 3 be­lieves it would be hard to ne­go­ti­ate all the ob­sta­cles on the fore­deck whilst teth­ered.

‘There are of­ten a limited num­ber of places to clip on, es­pe­cially in rough weather dur­ing a head­sail change, but I have never heard of a har­ness line fail­ing in this way be­fore,’ she said.

‘Much as this is a ter­ri­bly sad event, it does seem to be a freak ac­ci­dent and a stark re­minder that the risks of ocean sail­ing can never be en­tirely elim­i­nated,’ added Sprot.

Clip­per Round the World Race or­gan­is­ers have al­ready taken steps to min­imise a re­peat of a tether hook fail­ure. All of its yachts now have 10mm of rope wrapped around the cleats to the point that the tether now slides over them.

Chair­man of Clip­per, Sir Robin Knox-john­ston, said it was im­por­tant to learn the lessons from the tragic loss of Si­mon Speirs.

‘The Safety Bul­letin from the MAIB re­in­forces what we’ve said to crew at our Syd­ney stopover and we’ve taken steps to pre­vent a sit­u­a­tion like this ever oc­cur­ring again,’ he ex­plained.

‘Sail­ing is a safe sport but when we see some­thing like this, we need to put our heads to­gether to see what we can do to re­move the prob­lem.’

A tether hook, and a tether hook after lat­eral load­ing

Si­mon Speirs’ tether hook be­came caught on a deck cleat

Si­mon Speirs went over­board dur­ing a head­sail change

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