RENA Maritime NZ Update (108)
Monday, 24 October 2011 6:05 p.m.
Nearly a third of the oil on board the grounded Rena at Tauranga has now been pumped off the ship, but a challenging job still lies ahead for the salvage team, who must get further pumping systems in place for all the fuel tanks.
At 3pm today, a total of 481 tonnes of oil had been pumped off, helped by changes to the pumping system now in place for the port number 5 tank, which originally held 772 tonnes of oil.
Maritime New Zealand (MNZ) Salvage Unit Manager Bruce Anderson said two booster pumps had sped up this system but the 12-member Svitzer salvage team on the ship are planning further improvements.
In parallel with this work, the salvage team is also looking at how to get the 220 tonnes of oil out of the two settling tanks in the engine room. "The fuel pump connected to the settling tanks is in good condition, so the team is focused on how to get cabling in to power it up. They must then work out the best system for pumping that oil out," he said. "It's is not a simple task. It's a difficult job just getting in there."
However, the most challenging tank is the starboard number 5, which is under water and holds about 358 tonnes of oil.
Mr Anderson said divers were currently working on this tank in risky conditions. "The ship's corridor that the dive team is working in is dark, oily and full of water," he said.
"Luckily the tank is intact, in good condition and not leaking oil. The challenge is fitting a barrier or 'coffer dam' in the corridor where the tank is located so the salvage team can pump the water out, get a clear working space and start installing a pumping system for this tank. This is risky and takes time. They are diving in dark, murky passageways full of oily water and trying to get large, heavy pumps into position."
National On-Scene Commander Rob Service said no fresh oil had been released today from the ship.
The oil spill from Saturday night remains around theRenaand is predicted to move slowly north from Wednesday. Based on current conditions, some oil may reach Tūhua/Mayor Island.
"We sent a team to the island this afternoon to assess what we can do to protect wildlife if we get some shoreline impact there in the next few days."
He said the conditions on the water were "very dynamic", which made trajectory modelling difficult.
The Oil Spill Response Team is keeping a close eye on the oil through regular observation from the air and by boat.
Rob Service said MNZ was also working closely with public health officials to assess when the current beach access restrictions could be lifted.
"If we have no further oil spillages in the next few days and no more oil reaches the beaches, we hope to open the beaches by next weekend. But this will depend on our assessment and public health advice."
Diagram showing how Svitzer is pumping oil off Rena into the tanker Awanuia using a submersible pump and 2 booster pumps.
Image credit: Maritime New Zealand (Please click on the image to download a larger version.)