Urgent safety advisory issued after fatal tether failure in race

A competitor in the Clipper Round the World Yacht Race sailing in the Southern Ocean with the crew all tethered to the jackline © Clipper Race

Simon Speirs (60) was lost overboard on November 18, 2017 in the Southern Ocean © Speirs family

Simon Speirs was lost overboard while working forward and was caught by a wave, tragically his tether line hook distorted and released © Clipper Race

The British Marine Accident Investigation Branch has released an urgent safety advisory bulletin following the fatal man overboard incident during the current Clipper Round the World Yacht Race.

The incident took place in the Indian Ocean on November 18, when British solicitor Simon Speirs (60) went overboard from the yacht CV30 after being swept off the bow by a wave. Wind conditions at the time were 20kts gusting 40kts.

He was wearing the correct safety equipment at the time including a safety harness and tether which was attached to the boat.

The tether failed under load and broke. While Simon Speirs was recovered 36 minutes later, he was unable to be revived and was buried at sea some 1500nm from Fremantle.

The preliminary investigation has revealed that the snap clip used to attach Simon Speirs to the yachts jackline had caught under a cleat or similar fitting on the yacht and had become unable to be properly aligned when the man overboard load was applied.

As a result, it appears that the tether hook distorted because of the load angle and released.

The summary of the advisory reads: "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."

In other words, the tether hook must be free to slide on the jackline or other secure point. The tether hook is designed to be aligned with the angle of the load.

If the tether hook is not aligned to the tether load and has a lateral load applied it may bend/distort and fail to secure the sailor to the boat.

The tether and hook are supplied with one leading brand of safety equipment and similar styles are used by others. It is not known if the reason for the tether hook failure in Simon Spiers' instance has also been a factor in other incidents involving tether failure. According to the video below a tether with load in the designed direction will fail at 2000kgs. With the load carried at an angle the tether hook fails at just 200kgs.

Below Nic Douglass talks with Sir Robin Knox-Johnson and Matt Allen about the tether hook issue and what can be done short and long term about the situation, which is now known.

The full advisory bulletin reads:

Background The sailing yacht CV30 was taking part in the third leg of the Clipper Round the World Yacht Race having left Cape Town on 31 October 2017 bound for Fremantle, Western Australia. At about 1414 local time on 18 November 2017, the yacht was in position 42°30.3’S, 087°36.3’E, approximately 1500nm from Fremantle, when a crew member, Simon Speirs, fell overboard. He was attached to the yacht by his safety harness tether. The hook at the end of the tether that was clipped to a jack-line, deformed and released resulting in him becoming separated from the yacht. Simon Speirs was recovered unconscious onto the yacht but sadly could not be resuscitated.

For the Marine Accident Advisory Board website item click here

Tether hook - Figure 1 - Marine Accident Investigation Branch - photo © Marine Accident Investigation Branch

A safety issue identified during the investigation was that the hook on the end of Mr Speirs’ tether had become caught under a deck cleat (see Figure 1), resulting in a lateral loading that was sufficient to cause the hook to distort (see Figure 2) and eventually release.

Example of Tether hook distorted - Figure 2 - Marine Accident Investigation Branch - photo © Marine Accident Investigation Branch

The harness tether was certified under ISO12401 (Small craft – Deck safety harness and safety line – Safety requirements and test methods), which is the international standard applicable to this equipment. The standard contains detailed testing requirements that assume the tether and its hooks will be loaded longitudinally rather than laterally.

The tether hook was of a conventional design and quality of build and was commonly used by manufacturers of safety harnesses and tethers that were certified under ISO12401.

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.

Safety Lesson 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.

Reefing the mainsail in rough conditions in the Clipper Round the World Yacht Race - photo © Clipper Race