Apr 282010

Ethane bubbles to the surface, potential for explosion

What you see in the photograph is the result of a ruptured ethane gas pipe in Port Phillip, Australia. It was the result of poor communications, culture gap, key players kept out of the information loop and a pilot’s unchallenged decision to try and dredge the anchor of a drifting containership, APL Sydney.

It is an excellent example of a holistic accident and perhaps a timely reminder, with typhoons on the way to brush-up on anchoring in bad weather.

At 1428 on 13 December 2008, the Hong Kong registered container ship APL Sydney’s starboard anchor was let go in Melbourne anchorage. Four minutes later, the pilot left the bridge and by 1436, he had disembarked the ship. The 35 knot south-southwest wind was gusting to 48 knots. A submarine gas pipeline lay 6 cables (1.1 km) downwind.

By 1501, after dragging its anchor, the ship was outside the anchorage boundary. The master advised harbour control he intended to weigh anchor and was instructed to maintain position and wait for a pilot. At 1527, when weighing anchor was started after receiving permission from harbour control, the ship was within 50 m of the pipeline. While weighing anchor, the anchor dragged across the pipeline, snagged it at about 1544 and, subsequently, the anchor windlass failed.

At 1603, the pilot returned to the ship and, after discussions with the master and harbour control, he decided to dredge the anchor clear. At 1621, less than 1 minute after APL Sydney’s main engine was run ahead, the pipeline ruptured. There were no injuries and the pipeline was isolated.

Among the issues:

APL Sydney’s intended anchor position was unnecessarily close to the pipeline in the prevailing adverse weather conditions. Creating a lee when anchoring so that the pilot could disembark the ship increased the rate of its anchor dragging and the length of anchor cable deployed was barely sufficient for calm weather.

• When the master advised that he intended to weigh anchor and move the ship away from the pipeline, the shipping control officer, who had not monitored the situation, instructed him to maintain position and wait for a pilot.

• The master took no precautions and made no attempt to maintain the ship’s position by using its main engine and/or deploying more anchor cable. By 1527, the ship had closed to within 50 m of the pipeline and the pilot had not boarded
when harbour control gave the master permission to shift the ship and he began weighing the anchor.

• When weighing anchor, the main engine and helm were not used to effectively control the ship and prevent its anchor and cable dragging across the pipeline.

• At about 1611, the lack of appropriate information from harbour control about APL Sydney’s position in relation to the pipeline, and possible options being discussed without definite advice that slipping the anchor cable was the only
safe option, probably increased the pilot’s uncertainty.

•  The pilot had assumed that the anchor was not snagged and did not advise the master of a reason for changing his initial plan to slip the anchor cable. The master accepted the plan to dredge the anchor without querying the change of plan or expressing any concerns.

• The Port of Melbourne Corporation’s safety and environmental management systems did not adequately address the risk of an incident involving the ethane gas pipeline and shipping.

• An appropriate risk assessment to determine safe limits for the Melbourne anchorage boundaries from the gas pipeline had not been carried out. The events of 13 December 2008 indicate that a limit of about 3 cables was not a safe  clearance for all ships in all conditions.

• APL Sydney’s standard berth to berth passage plan form did not make adequate provision to consider anchoring-related details. The ship’s plan did not contain any detail for anchoring off Melbourne indicating that an appropriate, independent and unhurried risk assessment for anchoring was not completed beforehand. As a result, the pilot’s anchoring plan was accepted without properly assessing all the risks.

• APL Sydney’s safety management system did not adequately ensure that the master was certain about his overriding authority and responsibility with respect to decisions and actions aimed at ensuring the safety of the ship.

• The ship’s crew were not sufficiently familiar with its anchoring equipment, including the anchor cable bitter end release arrangement and hence undertook an unnecessarily dangerous operation to sever the anchor cable.

• The Port Phillip Sea Pilots pilotage safety management system did not provide APL Sydney’s pilot with adequate guidance with regard to anchoring in Melbourne anchorage or the risks associated with the gas pipeline.

• The Port of Melbourne Corporation’s shipping control safe operating procedures, the port operations handbook and shipping control staff training did not provide the control officer with adequate guidance and information to allow him to safely manage the events of 13 December 2008 and give appropriate instructions, advice and information to APL Sydney’s master and pilot.

Other safety factors
• APL Sydney’s windlass failed and its hydraulic motor casing shattered as a result of heavy load when the crew attempted to heave in the anchor shortly after it had snagged the pipeline. Fragments and debris from the shattered motor casing had the potential to cause injury.

• The ship’s working language, English, was not used by its crew for all communications on the bridge indicating that the procedure had not been effectively implemented on board the ship. This limited the pilot’s awareness, impeded teamwork, caused delays and increased risks, particularly those associated with releasing the anchor cable.

• The Port Phillip Sea Pilots pilotage safety management system policy to prevent mobile telephone use from interfering with safe navigation did not refer to any standard procedures or guidelines which could be followed by its pilots.

Download the ATSB Report


Sorry, the comment form is closed at this time.