A LOSS of power that temporarily immobilised the LPG tanker Gaschem Homer as it left the port of Brisbane occurred because two of the ship’s three auxiliary diesel generators had been incorrectly left in manual mode.
The German-owned, Liberia-flag vessel, on charter with two sisters to Origin Energy for gas distribution around Australia, NZ and PNG, was departing from Brisbane’s BP Products berth under pilotage at 1100 on 15 March this year when it experienced an electrical blackout, resulting in the total loss of all propulsion and steering control.
The ATSB found the crew’s oversight meant that when the bow thruster, an auxiliary propulsion unit, was engaged during departure, the resultant surge in electrical load led to an overload of the only generator providing power, and the subsequent tripping and blackout.
Power was able to be restored after about two minutes, during which time the pilot used the assisting tug to keep the ship within the shipping channel. Gaschem Homer disembarked the pilot as normal off Caloundra and continued its voyage.
ATSB chief commissioner Angus Mitchell noted that no injuries or damage occurred in this case, “but a loss of propulsion and steering for a ship in a confined area like the Brisbane River is a serious incident.”
Looking beyond this individual occurrence, the ATSB’s investigation identified Gaschem Homer’s safety management system did not have adequate controls to manage the risk of a complete power failure due to generators being inadvertently left in manual mode during manoeuvring operations.
Specifically, the ship operator’s safety management system had generic engine room operational procedures for its fleet. This meant Gaschem Homer’s safety management system did not consider the specifics of its systems.
“Industry practice dictates that a procedure should provide sufficient detail as to how a task is carried out, including when and by whom, while a checklist is typically purposed as a memory aid, itemising key actions to ensure nothing is overlooked,” Mr Mitchell said.
“In this serious incident, the pre-departure checklist was purposed as a substitute for a detailed procedure, but provided little in the way of specific and usable task descriptions. Consequently, the crew had to rely on memory and experience to complete critical tasks, which increased the likelihood of an oversight.”
In response, the ship’s manager has conducted a risk assessment and established additional controls to prevent total power failures, the Bureau reports.
The shipboard safety management system was also amended to include guidelines for blackout prevention and procedures requiring generators to be set for automatic load sharing before manoeuvring. Pre-departure and arrival checklists have also been amended, and a power demand matrix has been developed. The company has also introduced targeted training for watchkeeping engineers on critical power management and monitoring tasks.
“These safety actions adequately addressed the safety issue identified by the ATSB’s investigation,” Mr Mitchell said.
“But for all operators, this incident should highlight the importance of ensuring all risks associated with shipboard operations and critical equipment are identified, assessed and effectively controlled.
“A safety management system should encompass up-to-date and usable ship-specific procedures, as well as any additional technical controls if procedural barriers alone are insufficient to mitigate risk.”
Read the final report here.