Salvors working on the grounded container ship Rena say they don't know how long it will be before oil can be pumped from tank that is under the water.[image:3664:half:left]
To get at the 360 tonnes of heavy fuel oil in the starboard number five tank, 750 tonnes of sea water has been pumped into it, causing the oil to rise to the top of the submerged tank.
Svitzer's salvage master Drew Shannon says the team began pumping from the tank on Monday night but that was interrupted when an air pocket developed.
He says a connection known as a hot tap had to be installed to purge the tank of air.
When all the air has been removed, work will recommence on pumping out the contents of the tank.
Meanwhile, Mr Shannon says a test was done on Tuesday on the mooring capabilities of the barge that will be used to remove containers from the Rena.
He says the trial proved successful.
Maritime New Zealand says there is still a possibility more oil will leak from the grounded ship.