Last Rena OIl Pumping Starts
uPDATE: Salvors have begun pumping heavy fuel oil from the submerged number five starboard wing tank on the Rena.
MNZ Salvage Unit Manager Arthur Jobard said pumping began at 6pm yesterday and has continued through the night.
As of 8am, about 31 tonnes of oil had been transferred to the tanker Awanuia.
Pockets of air trapped in the Rena’s submerged starboard wing tank are believed to be the principal stumbling block preventing pumping of the last 358 tonnes of heavy fuel oil off the vessel.
MNZ salvage advisor Jon Walker, of London Offshore Consultants, said that every time the salvors began pumping oil from the tank, they encountered air and had to spend hours clearing and resetting the system before they could try again.
“This was extremely frustrating. They keep starting it. They get a flow and then they find they are pumping air so they have to go back, open lines, vent air and reset everything.”
This graphic shows inside Rena. The No.5 HFO starboard tank is shown with the bottom half full of the water that was pumped in to raise the oil to the top of the tank for hot tapping.
This graphic simulates the flooding of sea water inside Rena’s hull.
This graphic shows the stern of the Rena and the area of buckling.
MNZ Unit Salvage Manager Arthur Jobard said that the salvors had also traced the source of seawater which had been preventing the removal of the remaining 20,000 litres of lubricating oil from the engine room storage tank.
They were in the process of sealing the vents and would resume pumping the lubricating oil as soon as that was finished.
Divers report that there is no apparent change in the condition of the Rena’s hull.
Container removal contractor Braemar Howells used a helicopter to remove 51 cubic metres of debris from Motiti Island yesterday. This is part of their task of locating and removing wreckage and debris from the containers that were lost overboard from the Rena in the storm three weeks ago.
National On Scene Commander Rob Service said that work to clean up oil on the beaches had continued today, with a combination of New Zealand Defence Force personnel, trained oil spill responders from around New Zealand and Australia, volunteers and contractors.
One of the most heavily oiled areas of Papamoa beach was the scene of a surf washing trial, which Mr Service said had gone well and would be continued tomorrow. “Surf washing is a well established technique, which is being used for the first time in this response. A light “bobcat” digger excavates sand and deposits it at the water’s edge, where natural tidal movement separates out clumps of oil, which are then collected.”
Further trials of the Beach Tech Marina machine went well this morning. MNZ operations staff are looking at possible modifications to the equipment to see whether it could be made more effective, Mr Service said.
Oil spill operations in several areas, including Matakana Island, have been boosted with the arrival of six quad bikes on loan from Landcorp Farming Ltd. Mr Service said the bikes were being used to move equipment and personnel around more quickly and efficiently. “It’s a great example of the kind of fantastic support that we are receiving from all around New Zealand and overseas,” he said.