domingo, 25 de maio de 2008

Submarine's £5m repair bill blamed on tracing paper

Submarine's £5m repair bill blamed on tracing paper

HMS Trafalgar

Navy nuclear submarine HMS Trafalgar is escorted back into Faslane
naval base after running aground near the Isle of Skye. Photograph: Ben

A nuclear-powered Royal Navy
submarine needed £5m worth of repairs after it struck the seabed
because a piece of tracing paper covered its navigational chart,
investigators have found.

The tracing paper had been used on the chart to protect it from being written on, obscuring vital information.

Trafalgar was grounded near the Isle of Skye in October 2002 because of
basic navigational errors during a training exercise for students,
according to the official board of inquiry report, which has been
released under a freedom of information request.

According to the
report, just 90 seconds before the boat hit the seabed, a crew member
realised what was about to happen and was recorded as saying: "We're
going to have to change course. This is too dangerous."

warning came too late. Naval investigators noted: "At 0757, the
submarine grounded, striking the bottom heavily on the port side
forward. Speed 14.7 knots.

"On impact, the ship's head was forced
to starboard and there was a rapid deceleration, forcing most people to
lose their balance and causing at least three minor injuries."

his balance had been regained, HMS Trafalgar's commanding officer,
Robert Fancy, ordered the submarine to surface to check the pressure
hull had not been breached and the nuclear reactor had not been

The reactor plant was unaffected, but £5m of repairs
were needed on the hull, a complex structure made of thick
high-strength steel.

The involvement of unsupervised student
submariners in the navigation procedures and the use of tracing paper
on the chart were criticised heavily by the board.

The three
students, who were taking part in a submarine command course during the
exercise, codenamed Cockfight, had prepared a navigation plan that
assumed transit would be at periscope depth and "with frequent visual

Senior officers decided to test one of the trainees, Lieutenant Commander Tim Green, and changed the plan.

students had not anticipated that HMS Trafalgar would go deep and at
speed. "Consequently, it [the plan] was inadequate," the report said.

report said tracing paper had been a contributory factor in previous
groundings and recommended its use should be strongly discouraged.
It noted that the navigation plan had been "flawed both in concept and execution" and the chartwork supervision was inadequate.

commanding officer did not appreciate the inaccuracy in tidal stream
calculations, nor the importance it was to assume after going deep,"
the board concluded.

The spring tidal rate was not properly taken
into account when charting the course approaching a rocky islet,
Fladdachuain, near the Isle of Skye.

The speed of the submarine
was overestimated and "no account was taken of the time needed to
accelerate from four to eight knots. Untidy and inaccurate chartwork
made calculations difficult," it said.

HMS Trafalgar grounded "because of human error".

submarines should only conduct training of this nature if the
arrangements for navigational safety are infallible," the board said.

who was in charge of navigation, and Commander Ian McGhie, who was
responsible for the training course, were court martialled and
reprimanded for negligence.

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