SECTION 4 - Marine Accident Investigation Branch

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SECTION 2 - ANALYSIS
2.1 AIM
The purpose of the analysis is to determine the contributory causes and
circumstances of the accident as a basis for making recommendations to prevent
similar accidents occurring in the future.
2.2 ACCIDENT OVERVIEw
The process to prepare No 5 tender in readiness to evacuate passengers, as part of
the MCA’s expanded PSC inspection, should have been straightforward. However,
the first cook’s inadequate understanding of his lifeboat crew duties resulted in him
being unable to operate the forward bowsing gear and to release the tricing pennant
safely when instructed to do so. When the fourth officer saw that the first cook was
having difficulty in releasing the tricing pennant, he instinctively went to help his
colleague. This was entirely consistent with his supervisory responsibilities during
lifeboat drills. However, his intervention set in train a sequence of events which
resulted in the uncontrolled, coincident release of the forward bowsing tackle and
tricing pennant. This resulted in the fore end of the lifeboat swinging violently away
from the ship and then heeling to port. Without the protection of a safety harness
and tether, the fourth officer and first cook fell into the water as they lost their footing
on the smooth coach roof.
The subsequent rescue of the two men from the water, and their medical treatment,
was rapid and well-managed.
2.3 FAILURE MODE
When a lifeboat is lowered to embarkation deck level, the load is shared between
the falls and the tricing pennant with the tricing pennant load being appreciably less
than the lifeboat’s weight. When the bowsing tackles are connected and correctly
tensioned and the tricing pennants released, the bowsing forces are virtually
horizontal and the falls support almost all of the weight of the lifeboat. As the
bowsing tackles are released under control, the lifeboat adopts the plumb position
directly under the falls, and the fall forces and weight of the lifeboat are in line.
Controlled lowering can then begin. A schematic of the direction of forces is shown
in Figures 5 and 6 of Annex k.
During the re-enactment carried out on 29 March, it was possible to observe the
sequence of events which led up to the accident. As the first cook moved away from
the tricing pennant to provide space for the fourth officer, he moved the bowsing
tackle tail rope out of line with the bowsing block on whose bitts the rope was
secured. This resulted in the bowsing rope slipping entirely off the bitts because
the rope was oversize (see Section 1.12.1). The first cook then tried to maintain the
necessary tension on the bowsing tackle to keep the lifeboat alongside, but without
the assistance of it being secured to the bitts. At the same time, the fourth officer
released the tricing pennant hook. The first cook was unable to maintain the tension
on the bowsing rope and, without the bowsing tackle to restrain the lifeboat, the fore
end swung out violently to align the weight of the lifeboat with the falls. However,
the aft bowsing tackle was still secured, which resulted in the lifeboat adopting an
exaggerated heel to port, causing the fourth officer and first cook to slide off its
deck.