Is Northland's sunken treasure ship a ticking time bomb?
Wednesday, 30 August 2017
An underwater expert says if a 77-year-old wreck off Northland needs salvaging, so do the hundreds of other ships strewn across New Zealand's sea floor.
The RMS Niagara – an ocean liner bearing gold bullion, passengers, and oil – went down near the Hen and Chicken Islands, 40km southeast of Whangarei, after hitting a German mine during World War II.
It has been sluggishly leaking oil ever since.
Conservationists were worried that the 120m-deep wreck was an ecological disaster in waiting, but Maritime New Zealand remained unfazed.
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The wreck's owner Keith Gordon told RNZ there were about 1500 tonnes of oil still on board the Niagara, by his reckoning.
That was four times as much as spilled from the wreck of the Rena in 2011. That spill was described at the time by Environment Minister Nick Smith as the most significant in New Zealand history.
Gordon told RNZ the Niagara was a ticking ecological time bomb.
No lives were lost when the Niagara sank in 1940. It was heading from Auckland to Vancouver via Suva.
Most of the gold it carried was recovered in 1941, although five of the original 590 bars are believed to remain on the wreck.
Maritime New Zealand's general manager of safety and response, Nigel Clifford, said said the amount of oil on board when the Niagara set off was unknown, and much of that was already gone.
'There was significant oil loss when Niagara sank after hitting a mine, and then again when cargo salvage operations used explosives to breach parts of the hull and access gold bullion,' he said.
He said major leaks of whatever remained were unlikely due to the oil's 'near solid form'.
Niagara's oil was a type of heavy marine fuel with a high pour-point; the low temperature and depth of its watery grave would likely render it semi-solid.
Clifford said while there were 'occasional reports' of small amounts of oil coming from the wreck, these were monitored by Maritime NZ and the Northern Regional Council and tended to break up naturally without any damage to the environment.
The vessel was assessed in 2000 and there were underwater photographic surveys conducted in 2008 and 2016.
'Contingency plans have been developed that could be put into action if a significant discharge occurred.'
The Northland and Auckland Conservation Boards, however, have jointly called for the sunken vessel to be surveyed for a potential salvage mission.
Northland board chairman Willie Wright said after listening to a presentation by Gordon on Friday, his group 'felt it would be irresponsible not to try' to get the Niagara checked out.
'If the ship did implode, it would be devastating for our local environment.'
Wright said Gordon estimated a cost of up to $5 million for the survey, which his salvage company could carry out.
Wright said he did not know who would foot the bill.
Dive Co director Dayne Goodwin, who has nearly 30 years experience in underwater salvage and ship maintenance, said if salvaging the Niagara was deemed necessary, it would cost more than the Rena.
Rena's $700 million salvaging operation was the second most expensive in the world, after the Costa Concordia off the coast of Italy.
'It would be horrendously expensive and horrendously difficult.'
Goodwin said that as he understood it, the Niagara posed no greater risk than any other shipwreck around New Zealand's coast: 'If [it has] an oil tank full of oil, it could be seconds away from going or it could be 50 years away.
'No one's complaining about any of the others.'