An urgent safety bulletin has been issued by the MAIB on use of safety harness tethers on sailing yachts, following a fatal accident on board the sailing yacht CV30 in the Indian Ocean on 18 November 2017.
Finding from the MAIB report include,
- The deceased person was using a three-point webbing tether attached to the integral harness of his lifejacket that allowed him to clip on to the yacht with a tether.
- The hook on the end of the deceased’ tether become caught under a deck cleat (see Figure in the MAIB report), and resulted in lateral loading that caused the hook to distort (see Figure in the MAIB report) and eventually release.
- The harness tether was certified under ISO12401. However under the standard, the testing requirements assume that the tether and its hooks will be loaded longitudinally rather than laterally.
- 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 Learnt
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.
For more details and photos, click on the MAIB link below