The ATSB has found that the self propelled accommodation
platform Safe Concordia had been plagued by problems in
its electrical systems since its construction and these problems
had not been adequately addressed before the platform suffered two
electrical fires in its propulsion system after entering Bass
Strait in September 2005.
Safe Concordia is a dynamic positioning, self
propelled, semi-submersible accommodation platform that uses four
electrically driven thrusters to maintain its position. The
platforms construction and delivery trials were completed in March
2005. The platform was used operationally for its first contract in
the Timor Sea before modifications were made to address various
electrical problems that had occurred within its propulsion system.
After the modifications were completed, the platform sailed from
Singapore, bound for Bass Strait, Australia, where it was to be
positioned about 30 metres from the Yolla gas production
platform.
On 12 September 2005, after the platform had entered Bass
Strait, a fire started in one of the Safe Concordia's
thruster transformers. The Australian Transport Safety Bureau
investigation found that the transformer fire was probably the
result of an internal short circuit that occurred when the
transformer insulation failed due to overheating. The transformers
had overheated because of flaws in the design of the propulsion
electrical system.
On 18 September, while still in Bass Strait, a fire occurred in
an electrical cabinet that was providing power to another thruster
motor. The cabinet fire was probably the result of an electrical
arc that occurred when electricians had bypassed part of the
electrical system to try and diagnose the ongoing problems and the
execution of the task of bypassing the equipment was not adequately
completed.
The ATSB report also concluded that Safe Concordia was
not fit to fulfil its charter obligations in view of the unresolved
faults in the thrusters electrical power systems. The National
Offshore and Petroleum Safety Authority had not been made aware of
the problems and the design of the platform did not allow for
effective and safe fire fighting in the thruster machinery
rooms.
The ATSB has made several safety recommendations with the aim of
preventing further incidents of this type.
Copies of the report can be downloaded from the ATSBs internet
site www.atsb.gov.au