The spell of fortuitous weather that has blessed salvage recovery operations at the Astrolabe Reef are expected to end around midday Sunday, when the offshore wind swings to the east.
The 236metre long fully laden container ship, Rena, crewed by a crew from the Philippines, struck the Astrolabe Reef off Tauranga on the East Coast of New Zealand in the early hours of Wednesday morning, in calm weather.
She has struck fast on the reef, and the owners and insurers have appointed salvage experts to act on their behalf.
The weather has remained calm in the area, or with offshore winds providing calm seas for the ship, which has released some light oil, killing a few seabirds.
The wind change will produce much bigger waves than those currently being experienced. Although initially moderate, the winds will increase in strength to 18-20kts average with stronger gusts from an easterly or onshore direction.
Over Monday and Tuesday the winds will increase further to 25-30kts according to one of the base wind data feeds used by Predictwind. The second feed predicts a lighter windspeed but still very significant at 15-17kts on Monday and Tuesday.
Astrolabe Reef wind prognosis Friday 7 October to Tuesday 11 October. The two wind strength predictions are on the top two lines and the wind direction is on the third and fourth lines. The two prognoses are in reasonable agreement so the certainty of the prediction is quite high. - PredictWind.com?nid=89356 Click Here to view large photo
So far there has been no reported attempt to offload the 1700tonnes of fuel oil that are aboard the Rena, and which threatens the pristine coast off Tauranga on the East Coast of New Zealand.
Since striking the reef on Wednesday some light oil has leaked from the ship and the only action from authorities has been to spray this with detergent, with mixed results.
Inflatable barges available in New Zealand
Sail-World spoke to Ronald Winstone, Technical Director of Lancer Industries?nid=89356 who manufacture inflatable barges designed specifically to allow oil to be offloaded from ships which have run aground to prevent significant spillage and environmental damage. The barges from Lancer are owned by many maritime authorities around the world including the US Coast Guard.
'Lancer barges are designed to be taken alongside a vessel and have the oil pumped into them directly, before being towed ashore to a shore installation', Winstone told Sail-World.
A Lancer oil recovery inflatable barge under test in the Waitemata - the Lancer barges can operate in sea states of 6ft significant waves - Lancer Industries?nid=89356
'Martime New Zealand own two of our barges, and each has a a 100tonne capacity. The two barges are capable of doing two trips a day - so to offload the 1700 tonnes of oil would take around four days', Winstone said.
'The barges are capable of working in significant waves of six feet (two metres), which is a nautical term, but in effect means they can be used in wave of up to 10-15ft, in layman's terms', he added.
Winstone says the inflatable barges deflate into a pack the size of an office desk and are readily transportable.
All the major governments of the world have agreements in place to fly in equipment, in the case of an oil spill or pending disaster to offload fuel oil and reduce the extent of any damage. Additional barges could easily be flown in from Australia if required.
Maritime NZ's barges are believed to be located in Te Atatu and only a few hours trip by road to Tauranga.
Winstone says the Henderson based company have just made some barges for the US Coastguard of significantly more capacity than the two owned by Maritime NZ.
'The barges can also be used in a cleanup operation to skim oil that has already leaked, reducing the need to use dispersant', says Winstone.
Lancer have been manufacturing RIB's in New Zealand for almost 40 years and have led many of the developments in this field. For more on Lancer's backgroud click here?nid=89356
TV crews working in the area of the Rena, are reporting that significant amounts of oil are in the water off Tauranga already. One attempt on Thursday to use a helicopter to spray oil dispersant has been unsuccessful, further attempts are being made, with better success.
While operations can be very measured relaxed in calm weather when there is plenty of time to trial options, a change of wind direction can be very significant, both in terms of the options available and the ship breaking up in even just moderate seas.
Additionally a wind change to an onshore breeze would take oil spilled towards the east coast of New Zealand inflicting widespread environmental damage.