INVESTIGATION

CASE 3
The Lessons
1. A gog rope is commonly used to move the
effective towing point closer to a towing
vessel’s stern. This prevents the towline
from being taken across the towing
vessel’s beam, and therefore reduces the
danger of girting 1 . The mooring launch’s
management company recognised the
danger of girting and, consequently,
required a gog rope to be used on every
tow. However, it incorrectly assumed that
the mooring launch crew were proficient
in adjusting the gog rope to maximise its
preventive effect.
2. In this case, the gog rope was set at an
intermediate length that was neither
short enough to move the towing point
sufficiently aft to prevent girting nor
long enough to facilitate the coxswain’s
intended turn to port once load had
started to come onto the towline.
3. A thorough assessment of the task prior
to commencement, underpinned by
appropriate training highlighting the risk
of girting and how to prevent it, would
have enabled the mooring launch coxswain
to make a more informed decision on
what the optimum gog rope arrangement
should have been.
4. Effective proactive communications
between the tanker’s pilot and the mooring
launch coxswain at defined stages of the
operation would have reduced the risk
of girting. In this case, the pilot relied on
the coxswain to act autonomously and to
inform him when in doubt or difficulty.
1
‘Girting’ means the risk of capsizing due to high
athwartships towing forces.
Had the launch coxswain been warned that
the tanker was about to be manoeuvred
ahead or had already started to move
ahead, he might have been able to turn the
launch to port before additional loading
came onto the towline. Alternatively, he
could have informed the pilot of any doubt
he might have had in his ability to turn
the launch before the tanker gathered
headway.
The need to establish communications,
agree a plan and continually exchange
information, including engine movements,
is promoted in the Code of Safe Working
Practices for Merchant Seafarers and has
been a significant finding in a number of
MAIB safety investigations concerning
towing operations.
5. With no mechanical assistance, the towing
hook emergency release relied on the crew
to operate the manual pull in order to
release the towline.
Tests of the towing hook following
the accident demonstrated that, under
load conditions, a steady pull required
significantly more force to operate the
release mechanism than a sharp pulling
action, and that the required effort
increased in proportion to the loading on
the hook.
The emergency release had not been
practised as part of a drill, and so the crew
lacked preparedness to take appropriate
and rapid action in the event of a
developing emergency. How prepared are
you?
MAIB Safety Digest 1/2017
9