Crack team

6 min read

Part icebreaker, part drill ship, the Aurora Borealis will go where no lone vessel has gone before and could help unlock the secrets beneath the Artic seabed. Jon Excell reports

It Is a reality of scientific endeavour that the answers to the biggest questions are frequently found in the most out-of-the-way places. And few places on earth are less accessible than the Arctic Ocean, where winter ice several metres thick has long hampered attempts to probe a seabed thought to hold answers to fundamental questions about our planet’s past and the origins of life itself.

Help may soon be at hand in the shape of the Aurora Borealis, a £470m (€600m) European polar research vessel that could be probing the Arctic depths as soon as 2014. Bristling with advanced technologies and able to operate alone in one of the most inhospitable environments, the vessel, being designed by German naval engineering giant Schiffko, will be unlike any other.

Powered by a 55MW diesel electric generator, it will be an 185m-long, 50m floating Arctic university, a base from which the cream of the world’s scientists will perform meteorological, geological and biological experiments.

The vessel is the brainchild of the European Science Federation (ESF) and Germany’s Alfred Wegener Institute for Polar and Marine Research (AWI). Germany has already pledged funds, and project organisers hope to secure financial commitment from other European countries soon.

AWI’s Dr Nicole Biebow, the project’s manager, told The Engineer that the vessel will fill a huge gap in polar research capabilities. While existing research vessels have been able to operate only in the broken summer ice of the Arctic, the Aurora Borealis will plough through the 5m-thick ice of the winter.

The only ships capable of similar performance are Russian nuclear icebreakers such as the Arktika which, in 1974, became the first surface vessel to reach the North Pole.

Uniquely for an ice-class research vessel, Aurora Borealiswill also have a drilling capability to rival the best the offshore industry can offer. The contract for the drill-rig, which will be able to drill up to 1,000m beneath the seabed in water 5km deep, has not yet been awarded, but the system is expected to be a modified version of the well-established offshore technique in which a series of sections of drill pipe are connected to form a drill-string several kilometres long.

Paul Egerton, director of the ESF’s European Polar Board, said the drill, which will by deployed through one of the vessel’s two moon-pools (openings in the hull floor that give access to the water beneath the boat) will be specially designed with the harsh arctic environment in mind. ‘While most of the drill rigs operating at the moment are open systems, this one will be covered,’ he said. ‘The system will also be more efficient and will collect up the drill pipe and put it down the hole more quickly than existing systems.’

The vessel is expected to have a similar drilling capability to the Japanese research drill-ship the Chikyu which, as part of the ambitious NanTroSEIZE project, is drilling deep into an earthquake-generating region off the Japanese coast to gather seismological data. Dr Lisa McNeill, a Southampton University engineer involved in NanTroSEIZE, said one of the big technical challenges of any deep-sea drilling operation is using so-called dynamic-positioning techniques to maintain a vessel in position directly above several kilometres of drill-rig.

While this is challenging in open water, the problems are compounded when the vessel is being pushed around by huge blocks of drifting sea ice. ‘Dynamic positioning systems for vessels have so far only been developed for performance in open waters. To date, no vessel is able to dynamically position within severe ice conditions,’ said Lester Lembke-Jene, science and technical implementation manager for the Aurora Borealis.

The vessel is expected to use satellite guidance — either GPS or Galileo — with some form of azimuth propulsion system to prevent it from straying off-station during drilling operations.

Egerton said the final decision as to what kind of propulsion system to use will be left until the team has seen the results of a series of ice tank tests that will be carried out over the next few months at Aker Arctic’sfacilities in Finland. ‘A camera beneath the model will assess against the drifting ice and we will see how the system can respond using its propulsion systems,’ he said.

The fact that the vessel will spend much of its operational time floating over one point of the seabed means its structural design will differ considerably from that of conventional ice-breakers.

‘Ice is usually broken by icebreakers with some momentum,’ said Lembke-Jene. ‘If the vessel is static, there is only the movement of the ice as momentum, plus the vessel cannot always optimally face the main ice flow direction.’

Following earlier ice-tank tests, Schiffko’s engineers came up with a hull shape that is able to break ice in a sideways direction. ‘Most vessels break ice in a forward direction,’ said Egerton, ‘but the Aurora Borealis’s hull will be designed to be very steep-sided. This will mean that icebergs impacting upon the side will be crushed, going beneath the vessel, where they will be washed away by the propulsion systems.’

Egerton added that the constant passage of broken chunks of ice across the bottom of the hull has other design implications. The propeller blades will have to be specially strengthened, as will the exposed entrances to the two moon-pools. And there will also have to be some redundancy and duplication of engine power in case a propulsion unit is damaged.

In addition to the shape and strength of the structure, the team also hopes to pioneer a new artificial damping system that will compensate for the boat’s lack of forward ‘ice-breaking’ momentum by effectively bouncing it up and down in the water.

Egerton said the system, which has not yet been developed, will work by rapidly pumping several thousands of litres of water in and out of the vessel’s hull. ‘It will enable us to increase or decrease the weight and buoyancy of the vessel over a short space of time. Therefore, if we have an area where there’s very thick ice and we need to break out of that situation, the ship could be lifted up or down and the sheer mass of the vessel using this system would have a significant effect on the surrounding ice floe.’

Back on board, as well as enabling its team of about 60 scientists to drill beneath the ocean, the vessel will also be equipped with a vast suite of scientific instruments. Many of these will be housed in the numerous fully-enclosed research laboratories that will be arranged around a main atrium.

While much of the vessel’s most sensitive equipment will be sheltered from the elements, some instruments, such as the strings of sensors that will be used to take weather measurements and monitor the movements of the ice, will be exposed to the worst the Arctic can throw at them.

Egerton said this will call for the design and development of new rugged instruments able to withstand severe icing and operate at temperatures as low as -30ºC.

Much has been written about the vast untapped reserves of fossil fuels thought to lie beneath the Arctic sea-bed, and clearly a vessel with such advanced capabilities to analyse the seabed would be an attractive tool for the oil and gas industry.

Egerton confirmed there is already a great deal of industrial interest in the vessel and said he is setting up a contact group of industrial representatives who may be interested in using the ship to test new technologies in Arctic conditions and survey areas of the ocean floor using the ship’s seismic reflection equipment and seabed mapping systems.

Despite this, he is adamant that Aurora Borealis will be first and foremost a research vessel, and with so much pure science to do it seems unlikely the boat will be hijacked by the oil companies.

Egerton is particularly excited about using the ship’s two 7m by 7m moon-pools to send sensitive scientific instruments into waters that have previously been largely inaccessible. One such instrument is a seabed coring system known as the ‘calypso’.

Already used onboard French research vessel the Marion Dufresne, the device is a 6-tonne, 60m-long hydraulic lance which, upon reaching the seafloor, is triggered to collect undisturbed sediments from the seabed.

The moon-pools will also be used to launch both remotely operated and autonomous underwater vehicles into the waters beneath the ice. ‘It’s not currently possible to deploy this equipment in a closed sea-ice environment,’ he said, ‘but when you have a moon pool you are below the sea ice cover in open water and can bring them in and out without problems.’

Egerton said underwater vehicles could be used to look for organisms and collect samples. They could even be sent down to the seabed to collect images of areas of the earth’s surface that have never been seen before.

‘There are volcanic vents on the Arctic Ocean floor and these have great potential for finding forms of life that could ultimately have pharmaceutical, medical and genetic applications. These are areas of the planet that no one has ever seen before,’ he said.

By the end of this year the design will be finalised and a tendering process for the various elements of Aurora Borealis will begin. Egerton and Biebow hope construction of the boat will begin in 2012 and it will enter the water for the first time in 2014.

But before that can happen there are some considerable administrative and political challenges to overcome. Not only must the project team persuade a number of other European countries to stump up the money to finance a vessel that will cost €600m to build and about €25m a year to operate, they must also secure the collaboration of the Russians, who hold territorial sway over some key areas of the Arctic.

Despite relatively frosty relations in this area, Egerton is confident the Russians will be keen to co-operate on the project. ‘We hope that the Russians will be a major partner in the project — we’re already in discussion with the ministry of science and the hydrometerological service — and one of the things we have to do over the next 12 months is to really have political engagement between Russia and the EU.’

If the political solutions are as flexible and innovative as the work of the project’s engineers, it should not be long before Aurora Borealis begins to shine a light on the undisturbed seabed of the Arctic Ocean.