Salvage teams onboard the cargo vessel, which has been stuck on Astrolabe Reef off the Tauranga coast for a month, were making good progress and had resumed pumping oil from the last tank, Maritime New Zealand (MNZ) said tonight.
About 358 tonnes of fuel oil remains in the Rena’s submerged starboard five tank, while an unknown amount of engine oil remains in the engine room.
Bad weather forced salvage company Svitzer to suspend salvage operations and evacuate all personnel from the vessel on Monday but they returned on Wednesday and re-established the fuel removal systems.
In a setback though, MNZ salvage unit manager Bruce Anderson said dive teams today confirmed that a coffer dam, or water-tight barrier, salvors had been building to allow access to the submerged tank had been destroyed during the bad weather.
“Given the amount of time it would take to rebuild this, they have decided to focus their efforts on hot tapping,” Mr Anderson said.
Mr Anderson said it was a slower way to recover the oil but the best option available to the salvage team.
“The safety of the salvors is always the priority, and the destruction of the coffer dam really highlights how challenging the situation they are working in is.”
Mr Anderson said the team had set up two hot taps and was now pumping water into the starboard tank.
Another salvage team was pumping lubricant and hydraulic oils in the engine room into a centralised tank. These were being transferred to the barge Awanuia.
Svitzer was now looking ahead to the next phase of the salvage operation and preparing to remove containers from the vessel.
The crane barge ST60, from Gladstone in Australia, had arrived and would be used to remove containers once the fuel recovery was complete.
“Salvage efforts have concentrated on fuel recovery as the first priority of the operation. However, behind the scenes, a lot of work is also going into preparing for the second stage, which is removing the containers and, eventually, the wreck,” Mr Anderson said.
Meanwhile, national on-scene commander Alex van Wijngaarden said volunteers had so far dedicated a total of 13,000 hours to the clean-up effort on the Bay of Plenty coastline.
“This is truly a massive effort and we are hugely grateful. We really couldn’t do it without them,” he said.