The loss of the anchor handler
In 2003 a routine task suddenly became a disaster
Although industry experts who have worked or work in the North Sea
have described the BOURBON DOLPHIN tragedy as 'unprecedented', this
can only really apply to the North Sea. It isn't the first time an
Anchor Handling Tug (AHT) vessel has sank during routine anchor
handling operations in this manner.
On 19th October 2003 a Danish AHT, the STEVNS POWER, sank whilst
operating off the Nigerian Coast. She was at the time moving an
anchor, one of 12, that was holding the position of the CASTORO OTTO,
a pipe laying vessel.
Unlike the BOURBON DOLPHIN she was not a new vessel, being built in
1976, but the procedure was one she and her crew were largely familiar
with and had been doing so regularly for at least two years with the
It is the job of an anchor handler to re-position the anchors that
keep a rig or other sea platform in their desired position. The
CASTORO OTTO was laying a gas pipe and needed to relocate her anchors.
Late that afternoon STEVNS POWER began operations to relocate anchor
No.10. She lifted the anchor off the sea bed and indicated she had
done so and CASTORO OTTO's winch then began pulling the anchor wire
with STEVNS POWER manoeuvring astern as this was done.
The tug then executed a turn, necessary to keep the anchor cable
following a straight line to the new position for the anchor, when
suddenly she heeled over. It appeared that her stern plunged below the
surface of the sea and within a minute the vessel was so overpowered
by the ingress of water she capsized, leaving just her bow sticking
out of the water.
None of her 11 crew survived the tragedy.
A subsequent inquiry concluded that factors which had contributed to
the loss of the vessel and her crew included:
Lack of proper safety procedures between the pipe laying vessel and
The practice of having very little freeboard aft to allow easier
lifting of the anchor buoy
The turning manoeuvre and the speed at which the anchor line was pulled
in from the client ship.
The tug was going astern too fast.
Open hatches and perhaps open watertight doors (the heat in the region
probably meant crew left doors open instead of closing them as is
normal practice during anchor handling)
There were other factors that could have contributed, but the inquiry
did not have sufficient evidence to establish if they did: these
included the anchor wires snagging, failure of steering gear (the
STEVNS POWER had had problems with this before the incident), lack of
experience on part of the navigator at the helm at the time or fatigue
on his part.
The report also concluded with a warning to crews not to
wish for speedier, but safer operations. A few minutes saving was not
worth the risks involved.
The tragedy focussed minds on how potentially dangerous anchor
handling is. Here were experienced hands on a vessel that had
performed such tasks over and over again, often many times in a day,
and in the relatively calm waters off the African coast.
Every day in our waters these vessels, with the expertise of their
masters and crew, bravely carry out their duties in seas that can be
hostile indeed. The general public never give such matters a second
thought, nor do many shipping buffs for that matter, and whether or no
the BOURBON DOLPHIN tragedy proves to have any similarities with the
one in 2003, we must always remember that it can take just one minute
for any operation to change from routine to disaster.