The master of a bulk carrier took almost an hour to notify authorities its engine had failed before the vessel moved dangerously close to hitting the NSW coast.
The engine gave out on Hong Kong-flagged Portland Bay at 6am amid heavy seas on July 4 last year, but authorities in Port Kembla were only informed at 6.58am - hours after smoke was first detected onboard.
The Australian Transport Safety Bureau has released a timeline of events ahead of a safety analysis and report into the incident.
"As the investigation continues, we will review the ship's activities and movements in relation to calling at Port Kembla and conduct further analysis of data from the voyage recorder to verify key event times," the bureau's transport safety director Stuart Macleod said.
The ship was instructed by Vessel Traffic Services to leave Port Kembla on July 3 as rough conditions risked damage to the wharf and ship.
Early on July 4 the main engine was cut, but was restarted at full speed ahead after the ship surged and rolled heavily in rough seas.
At 4.50am two fire detectors in the engine room went off before smoke was identified and the engine speed was reduced at about 5am, the bureau's report said.
The chief mate began slowing down the main engine and minutes later, the engine setting was reduced further to dead slow ahead.
The master notified the ship's managers of the main engine failure and the vessel's situation at about 6am but did not alert Vessel Traffic Services.
At 7am the master broadcast an urgency message when the carrier was 11 miles south of Botany Bay and 5.8 miles from the nearest coastline.
Marine Rescue NSW in Port Kembla acknowledged this urgency message but the Australian Maritime Safety Authority was not notified by traffic services until 7.44am when the ship was at risk of grounding on the coast in 90 minutes.
About 8am, the authority started planning for a possible evacuation of Portland Bay's crew in the event that the ship grounded on the rocky coastline, endangering the crew.
Fifteen minutes later, Portland Bay's master broadcast distress alerts on maritime satellite communication systems and marine radio frequencies.
At 8.30am the master sounded the ship's general emergency alarm and gathered the crew as he contemplated abandoning the ship.
Three rescue helicopters arrived at the ship at 9am but had to abandon a plan to winch the crew to safety due to the ship's instability.
When the ship was about one nautical mile from the nearest coastline and in water depths of about 45m, the master was able to anchor it.
Tug boats punched through dangerous seas to rescue the ship's crew.
The bureau's final report will assess several factors which caused the accident including emergency response aboard the ship and the response by state and national authorities.
