Published on Australian Maritime Safety Authority (https://www.amsa.gov.au)
The crack was reported to be 13 x 6 metres, and extended two metres below the waterline. A report received later that day indicated the vessel had lost 14,800 tonnes of oil.
Following the report, the Marine Operations Centre diverted the tanker British Unity to assist. The two vessels were en route to the Port of Fremantle, however both were ordered to head for Barrow Island to the north, as it was considered to be the least environmentally sensitive site of the practical alternatives. It was proposed that an inspection be carried out while the ship was anchored at least 50 miles from Barrow Island.
On 16 July a team of oil pollution and ship repair experts boarded the damaged vessel, including:
The reason for the crack was determined to be over-stressing of the 20 mm thick plates due to constant flexing in that part of the hull.
A second tanker, Donovania, was chartered to take on the remaining 48,000 tonnes of oil. The discharge of oil from the Princess Anne Marie to the Donovania commenced on 30 July 1975. The process was divided into nine stages over the course of four days and there was no evidence of further pollution during this time.
On 9 October 1975 the Princess Anne Marie departed Dampier after the completion of temporary repairs to the satisfaction of the Department of Transport, Lloyds and the insurance underwriters.
The vessel steamed slowly to the Singapore dry dock accompanied by a Singapore-based tug.
Read about Australia's National Plan for Maritime Environmental Emergencies.