Salvage operations on board the stricken cargo ship Rena are entering a new phase with pumping of heavy fuel oil from the ship now completed.

Maritime New Zealand says the bulk of the heavy fuel oil has been pumped from the submerged starboard number five tank and salvors can now focus on starting to remove the 1280 containers on board.

The stricken cargo ship Rena on Astrolabe Reef, carrying 1280 containers, which will start to be removed this week. Photo: LOC

Pumping was stopped on board the ship this morning when salvors reached the interface between the oil and water in the tank, and began pumping seawater.

'The bulk of the heavy fuel oil has been removed from Rena. There is still a small amount still in the tank but this is residual oil.

'This oil will still be pumped from the tank but salvors now have to wait for the oil to rise to the top of the tank,” says MNZ spokesperson Sophie Hazelhurst.

Salvors have been continuously pumping the estimated 358 tonnes of remaining heavy fuel oil from the Rena, grounded on Astrolabe Reef, onto the barge vessel Awanuia since Wednesday, November 9.

The Awanuia barge vessel is set to be released from Rena today.

'Salvors can now start on the second phase of operations. The pumping of the residual oil will continue, it can be done in parallel to the removal of containers.”

Work is continuing to strip the remaining accessible oil in other parts of the ship including the residual oil from the port number five tank.

The port number five tank held 772 tonnes of heavy fuel oil when Rena grounded on October 5. Salvors ceased pumping oil from this tank on October 27, leaving only remnants of oil.

As part of the "stripping" process, salvors will now revisit this tank to remove the last few tonnes.

Transport Minister Steven Joyce says the operation is now in a transition phase - shifting from oil recovery to container removal.

'I've been advised that the crane barge ST60 will be in place tomorrow and will take the bulk of the day identifying the best position to anchor before starting the complicated container removal process.”

'The fragile state of the ship and precarious positioning of the 1280 containers aboard means this will be a long process, with no more than about six containers removed each day dependant on sea conditions.

'While there is still a long, hard road ahead, the first priority has always been the safe removal of oil from the Rena and it is a huge relief to everyone involved that that has largely now occurred.

Steven thanked salvors and volunteers who have been involved with the cleanup effort and the people of the Bay of Plenty for their support to date.

'This is not a situation anyone would wish to occur but I am very pleased with the salvage and clean up efforts to date.

'There is, however, a strong possibility that some oil remains trapped in the vessel (i.e. in the duct keel) and that it could be released if the Rena breaks up, or when the wreck starts to be removed in phase three of the operation. However, the vast bulk of the 1,350 tonnes held in tanks on the ship has now been removed.