MO-2008-203

On 2 May 2008, the Bluebridge passenger and freight ferry Monte Stello was transiting Tory Channel in Marlborough Sounds en route from Picton to Wellington when it suffered an electrical power failure, resulting in a loss of both propulsion engines. The emergency power system started automatically and supplied power to critical systems. The ship was brought up to its starboard anchor about 250 m from the shore line.
Power was restored and the ship proceeded back to Picton where the passengers and freight were put ashore to allow the ship to return empty to Wellington to investigate the cause of the power failure.
Two diesel generators were supplying power to the ship when first one, then the other, tripped off the power distribution bus-bars. Additionally the programmable logic controller (PLC) for the engine room alarm monitoring system developed an irreparable fault, but it could not be established if this was linked to the power failure or was a separate event. The cause of the diesel generators tripping off the bus could not be conclusively determined.
Safety issues discussed include: the difficulties in maintaining equipment on ships when information on maintenance and modifications to systems have not been passed on from previous owners; equipment and system drawings do not match the installation; and manufacturers of equipment and systems consider them obsolete and no longer support them.
A safety recommendation was made to the Director of Maritime New Zealand (Maritime NZ) that this report be sent to the International Maritime Organization (IMO), bringing to its attention the safety issue that there is no mandatory requirement for continuity of ships maintenance records and system diagrams when ships change ownership, and inviting it to refer this report on to the appropriate committee for its consideration.