The Niagara pictured departing Sydney for Vancouver on August 28, 1924. The passenger liner was requisitioned for service during World War I and II and sank on June 19, 1940 after she struck a mine laid by Germans off New Zealand. Photo / Australian National Maritime Museum
The Niagara pictured departing Sydney for Vancouver on August 28, 1924. The passenger liner was requisitioned for service during World War I and II and sank on June 19, 1940 after she struck a mine laid by Germans off New Zealand. Photo / Australian National Maritime Museum
Documents reveal a World War II-era shipwreck could trigger a $200 million oil spill clean-up but the Government is going against officials' advice to at least do a risk-assessment survey.
In June 1940 the RMS Niagara was sailing out of Auckland for Vancouver, Canada, with 349 passengers and crew on board.
It was sunk by Germany in the Hauraki Gulf but decades later its oil has never been retrieved.
Maritime NZ had been recommended since 2019 to survey the Niagara shipwreck to work out how much oil is on it, but successive governments have declined.
New documents released to RNZ reveal it could cost $200m to clean up an oil spill from the ship and it would cause widespread damage over a large area.
The papers show a two-part survey of the ship would cost just over $13.7m.
Maritime NZ has said the costs are not insignificant but are “minimal compared with the potentially very high costs associated with a large oil spill”.
One of the many holes in the RMS Niagara, as shown in this screen grab from ROV footage. Photo / New Zealand Defence Force
Associate Transport Minister James Meager said there were no plans to survey the ship at this stage.
That’s despite Maritime NZ having warned that if a major spill occurred, the Government would face criticism that with plenty of warning the environment had suffered negative effects.
What happened in 1940?
The RMS Niagara’s journey to Canada was cut short when it was sunk by mines laid by the German naval cruiser Orion in the Hauraki Gulf – the first act of war against New Zealand by Nazi Germany.
It sank approximately 32km offshore of the Northland coast and now lies 120m below the ocean close to the marine boundary between Northland and Auckland.
In the 1940s and 1950s, operations were conducted to take 585 gold ingots owned by the UK treasury off the shipwreck – however, they did not remove any oil from it.
As the wreck nears 85 years old and continues to deteriorate, Maritime NZ and the Government have been keeping a close eye on the possibilities of a major oil spill.
It is unknown how much oil is on the ship, but Maritime NZ believes it’s “furnace oil” which is described as dark, thick and when spilled, would persist in the environment for some time.
The vessel had the capacity to hold 4324 tonnes of oil.
Salvaging from the wreck of the Niagara off the Northland coast in 1941 - a year after it was sunk by a German mine.
How much would an oil spill cost?
Ministerial briefings revealed to RNZ under the Official Information Act show that in October last year, then Associate Transport Minister Matt Doocey was told by Maritime NZ in a briefing the potential cost of a significant oil spill caused by the wreck.
“Detailed economic modelling of the direct costs of a response to a significant oil spill from the wreck was completed in 2020 and assessed that for a spill of 1600 tonnes direct costs would be in the order of $108m (approximately $200m in 2024 prices).”
The agency said the $200m figure did not include indirect costs, the costs to natural capital and reputational damage.
The same document said that about 27 species of birds breed nearby the wreck which included five that breed exclusively in that area.
One of those birds is the New Zealand fairy tern of which there are only 40 individuals left in the population, making them New Zealand’s rarest breeding bird.
Maritime NZ said the release of oil from the wreck was likely to cause widespread damage over a wide area in a region with “significant scientific, cultural, economic and reputational value”.
How can volume of oil be calculated?
Because there is no official word on how much oil could be on the RMS Niagara wreck, Maritime NZ has recommended for years to conduct a two-part survey of the wreck.
The agency applied for government funding for the survey in the 2019 and 2020 budgets under the Labour-led Government – both were declined.
The first stage of the work would be a visual survey of the wreck to work out its state of degradation.
Information could be captured by visual imagery, video footage, sonar and laser scanning which could be used to generate a 3D model of the wreck.
The second stage would involve the measurement of hull thickness and contents of the vessel’s available bunker tanks using a technique called neutron backscatter.
Associate Transport Minister James Meager. Photo / Mark Mitchell
In a briefing from 2023, Maritime NZ stated because of the way the wreck is lying many of its fuel tanks are inaccessible, meaning that the surveys may not inform a complete risk assessment.
Maritime NZ still recommends that the surveys are conducted.
In October the agency said latest estimates show the total survey costs would be $13,741,000 – the first stage would cost $1,300,000; the second stage would cost $12,441,000.
The cost of the survey is driven up by the wreck’s proximity to the Southern Cross transmission cable, which means the work would need to be done by a boat that can do the work without using an anchor.
The cost of that vessel could make up $7.5m of the survey total.
In the 2023 ministerial briefing it also stated if a significant oil spill eventuated the likely critique will be “with plenty of warning, time to prepare, options to manage the risk, and the environment has suffered avoidable negative effects”.
The same paper said there had been reports of oil leaking from the ship in February 2016, May 2019 and August 2023.
The Niagara, a frequent visitor to Auckland, was the first large passenger liner to use oil fuel for four of her eight boilers.
How much would it cost to remove oil?
If through surveying it confirmed a significant amount of oil was on the boat, the Government would have to consider how it could remove it.
In the October 2024 ministerial briefing it stated the cost of removal would be dependent on factors such as the location of the wreck and the availability of workers, vessels and equipment.
Maritime NZ said there would likely be significant technical challenges with accessing tanks on the low side of the wreck.
It said when the US National Oceanic and Atmospheric Administration and the US Coast Guard decided to remove oil off a ship of similar age in 2003 it cost $31m at the time.
That would be $51m in today’s prices; however, Maritime NZ noted the ship was only at a depth of 53m, significantly shallower than the RMS Niagara at 120m.
The documents said the greater depth would likely increase costs and challenges with any oil removal operation.
What does the Government say?
Meager declined a request from RNZ for an interview but provided a statement that said no plans for a survey were in the works.
“The Government does not intend to conduct the survey of the Niagara at this time.”
