Use of safety
harness tethers on sailing yachts
Fatal accident on
board the sailing yacht CV30 in the Indian Ocean on 18 November 2017
MAIB SAFETY BULLETIN 1/2018
This
document, containing safety
lessons, has been produced for
marine safety purposes only, on the basis of information available to date.
The Merchant Shipping (Accident
Reporting and Investigation) Regulations 2012
provide for the Chief Inspector of Marine Accidents to
make recommendations
or to issue safety lessons at any
time during the course of an investigation
if, in his opinion, it
is necessary or desirable to do so.
The Marine Accident Investigation Branch is carrying
out an investigation into the fatal man overboard accident
on board the commercial sailing yacht CV30, which was taking part in the Clipper Round the World Yacht Race.
The safety
issue
raised in this safety bulletin highlights just
one of potentially several factors that contributed to this tragic accident.
The MAIB will publish a full report, including all identified contributing
factors, on completion of the investigation.
Steve Clinch
Chief Inspector of Marine Accidents
NOTE
This
bulletin is not written with litigation in mind and, pursuant to Regulation
14(14) of the Merchant Shipping (Accident Reporting and Investigation)
Regulations 2012, shall not be admissible in any judicial proceedings whose
purpose, or one of whose purposes, is to apportion
liability or blame.
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.
INITIAL FINDINGS
Simon
Speirs 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 short or long tether.
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.
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.
Issued January 2018
Figure 1: Tether hook under deck cleat
Figure 2: Example of
a tether
hook and a tether hook after lateral
loading
Extracts from The United Kingdom Merchant Shipping
(Accident Reporting and Investigation) Regulations 2012
· Regulation 5: “The sole objective of a safety
investigation into an accident under these Regulations shall be the prevention
of future accidents through the ascertainment of its causes and circumstances.
It shall not be the purpose of such an investigation to determine liability
nor, except so far as is necessary to achieve its objective, to apportion
blame.”
· Regulation 16(1): “The Chief Inspector may at
any time make recommendations as to how future accidents may be prevented.”