The British Antarctic Survey has for more than 60 years undertaken most of Britain’s scientific research on and around the Antarctic continent. Conducting their research by land, sea and air, the survey’s staff help to unlock the secrets of the frozen continent and give the scientific community a greater understanding of globally significant issues, from biodiversity to climate change.
Managed from its Cambridge base, and a component of the Natural Environment Research Council, the British Antarctic Survey (BAS) is a huge operation, boasting more than 400 staff and a budget of £50.4 million for 2014-15 alone. Of this, £12 million is spent on the science programme, and £38.3 million spent on supporting the science, which includes the costs of running five research stations in the remote and harsh region. Much of the BAS research, long-term observations and surveys of Antarctica are conducted from its three stations at Rothera, Halley and Signy, and its two stations on South Georgia, at King Edward Point and Bird Island.
Steve Bremner is head of mechanical engineering for the BAS, and has been working at the organisation, along with colleague Andy Tait, a design engineer, for more than 25 years. Over this time Bremner and Tait have designed and developed an eclectic range of scientific equipment, from ocean instrumentation and loggers for tracking migrating birds to coring and drilling systems that can bore down hundreds of metres into ice shelves.
An ice-core drill that they developed has helped scientists in the Antarctic to look at climate change over many centuries, and in some cases thousands of years. One 55cm ice-core sample recovered by the drill that Bremner and Tait designed represented 230 years of climate history.
Bremner says: “Ice traps air over time. That air is a record of the atmosphere at that particular point in history. By looking at the impurities in the trapped air they can calculate what particular year a significant event happened, such as the eruption of a large volcano. This can be used to build up a historical record, and if you have past history of climate you can plot future trends.”
Often their work takes them the thousands of miles away from their Cambridge base to Antarctica, sometimes for years at a time.
Back in the 1980s, Tait spent two-and-a-half years living in an underground base called Halley 4. A qualified electrical engineer, he was to be trained in meteorology while on location and help to conduct experiments. This involved releasing meteorological balloons each day into the freezing cold air of an Antarctic winter in 24-hour darkness.
“You lived underground in tubes. There were 18 of us down there at one time,” says Tait. “Living on the base was quite amazing. The coldest temperature we had was –60°C during the depths of the winter.”
Normally the team conduct experiments during the Antarctic summer (our winter), with temperatures more comparable to those encountered on a skiing trip, around –5 or –10°C. Because of the reflective light from the snow it would even be warm enough for the team to go out in T-shirts, but as the wind gets up it becomes very cold very quickly, says Bremner.
“It is an absolutely beautiful continent with the most extremes that you can imagine,” says Tait. “From complete flat calm blue skies and lovely sunshine to blowing gale-force winds and freezing temperatures, such that it would be difficult to breathe and move quickly.”
The BAS engineers don’t just work on the mainland Antarctic. They can also be stationed on the wetter and windier sub-Antarctic islands, such as South Georgia and the South Orkney Islands, or on ships that can be battered by high winds and 15-20m waves.
Sailing into mid-life: RRS Ernest Shackleton has traversed the icy Antarctic seas since 1995, and is set to retire by 2019
Bremner and Tait have worked extensively on board the two ice-strengthened ships that sustain the Antarctic operations. RRS James Clark Ross has advanced facilities for oceanographic research, while RRS Ernest Shackleton is primarily a logistics ship used for the resupply of stations. “Working on board a ship requires a set of skills that are different to those needed to working on the continent,” says Bremner. “When you are at sea, the conditions can be horrendous – it gets so bad that you have to stop what you’re doing as it is just unsafe.”
While these ships have been supporting the BAS operations for decades, working in such extreme weather conditions and keeping pace with the latest technologies and instrumentation means they have a limited shelf-life of around 30 years. James Clark Ross was built in 1990 and is due for an upgrade, says Bremner. “It still has some life left in it but obviously systems on board become difficult to support. You have to make a judgement as to what you’re going to do. You can’t continue just servicing and maintaining the older systems. You have to make some major improvements on board to keep it going for another 20 years.”
Last year BAS made the ambitious decision to apply for government funding not only to extend the life of James Clark Ross but also to build a new polar science ship by 2019. Ultimately this vessel will take on the combined roles of James Clark Ross and Ernest Shackleton. Bremner is tasked with overseeing this project, alongside his day job, and his team of engineers, along with additional input from marine engineering firm Houlder, put together a case for the new ship and created an initial design to present to government. They were awarded £220 million for the project.
Since last April the initial design has gone through many changes, with the BAS team continuing to refine it each month before it goes out to tender in March 2015. As Bremner testifies, planning and designing a one-off polar research ship is no mean feat. “You must consider the scientific work that will be carried out on board, the routes it will travel, the weather it will endure, not to mention the costs and timeframe of the build,” he says.
“We knew the kinds of things we needed to include, knowing what works on our current ships, but we needed to add some capability and value for the future as well.”
This has included plans for a helicopter deck which will be able to fit two Super Pumas side by side. While the BAS doesn’t currently own helicopters, having them would provide significantly greater geographic coverage. Bremner says the helipad was considered to be part of “future proofing” the new ship. “We don’t own helicopters but who knows in the future we might have the ability to lease them or own them ourselves,” he says. Rather than the space needed for the helipad lying vacant, it will be used by flexible laboratory configurations for scientists to bring their own kit and experiments on board.
The ship will also carry an array of sophisticated environmental monitoring systems that will provide data from the ocean, measuring the conductivity, temperature and depth of the water. Acoustic Doppler current profilers will measure the current flow, while other on-board instruments will measure plankton. As well as this, the ship will have underwater autonomous vehicles (UAVs) and remotely operated deep-sea vehicles (ROVs), which will explore the seabed in unprecedented detail.
But the handling systems that place these ROVs over the side of the ship and into the water can weigh in excess of 15 tonnes. This has previously caused logistical issues for the crew operating James Clark Ross, says Bremner. “Working where we do in Antarctica there is no shore-side lifting capability, as well as in places like the Falkland Islands which is our port of call when we go south.” This has meant the ship has previously had to travel as far as Cape Town in South Africa, or occasionally to ports in South America, to get a larger lift capacity.
Bremner says: “Consequently we are paying very high costs to ship that to somewhere like Cape Town and steam from Antarctica to Cape Town – a 10-day trip at £10,000 a day for fuel – just to put that piece of equipment on.”
To overcome this problem, the new ship will have cranes with a lift capacity of 35 tonnes, so the BAS will be able to ship the equipment to a port of convenience and pick it up on passage, saving time and money.
When there are heavy pieces of equipment being lifted over the side of the ship, you also need to be able to keep the vessel steady using dynamic positioning. In mid-water a ship’s position is controlled by thrusters, explains Bremner. James Clark Ross has just one thruster fore and aft and a propeller to steady the ship, so it has been awarded a low dynamic positioning class of 1 (DP1). However, Ernest Shackleton, which was originally built as a rig supply vessel, has DP2 class and can work safely alongside oil rigs and pipelines.
“The Shackleton has four tunnel thrusters, an azimuth thruster that rotates 360° and its propeller, which when combined with navigation equipment is able to hold station within a 1m circle,” says Bremner. It is hoped to replicate this level of capability on the new ship, but avoid the official DP2 status awarded to Shackleton as there are stringent regulations and rules that govern ships with this class.
Of course, much of the new ship’s design will be focused on ensuring that it is able to cope with the extreme weather it will face in the Antarctic. “Everything we will do on the ship we have to take into account the conditions the equipment can work in,” says Bremner.
The crew will have a predetermined “weather envelope” in which equipment like the 15-tonne system for deploying remotely operated vehicles can be used, known as a sea state. For example, sea state 5 is characterised as “rough” with wave heights up to 4m.
To monitor the weather effectively the new ship will have Polar View, a product developed by BAS that collates satellite imagery from a range of sources and provides a detailed picture of the forthcoming weather fronts and sea-ice conditions. The crew will then be able to tell when to bring equipment in and batten down the hatches – although sometimes this only gives them a matter of hours to retrieve the kit before a storm hits, “which can make life tricky,” says Bremner.
Even when working with the latest technology the crew can be caught by surprise. Bremner says: “I’ve been on the James Clark Ross when it did a 42° roll in both directions. Basically anything that is not bolted down, and anything that is bolted down poorly, is on the floor. It can be quite a dangerous environment but we mitigate that by preparing for it.”
The ships must also be robust enough to travel through thick sea ice. While the exact specifications have yet to be determined, the BAS team will increase the new ship’s ice-breaking capacity, working within an envelope of operation of a metre of ice at 2 knots. “To do that we don’t need to increase the hull at all, as both of our current ships could cope with that,” says Bremner. “It is more to do with the propulsion.”
While James Clark Ross has a propulsion of 6.5MW, and Ernest Shackleton 8.2MW, the new ship is to have a much larger propulsion capacity of 15-18MW. This will be settled upon following further calculations to determine the hull form, ice stiffness and thickness the ship will encounter.
For the inevitable times when the ship is ice-bound, says Bremner, the BAS team have opted to include a moon pool; a hole that runs through the ship that will allow ROVs and UAVs to be deployed directly into the ocean.
It isn’t just environmental factors that affect such decisions. As a research ship, the experiments run on board, or that are launched from the ship, will determine much of the vessel’s final design.
One of the ship’s major tasks will be to deliver acoustic information for the host of on-board experiments, including the task of measuring and 3D mapping contours of the seabed. This will be achieved using the latest bathymetry system, which sends an acoustic signal down to the seabed, which then bounces back to be analysed on board.
“To do that you need to make sure the acoustic signature of the ship is as close to zero as you can get it,” explains Bremner. “Anything on the hull will have an effect on acoustic signals, hence it must have a streamline aerodynamic shape. Otherwise it will produce a lot of aeration and that noise basically precludes you from getting good signals.”
This also impacts on what motor is chosen for the ship. A small motor would not interfere with the acoustic data but would limit the distances the ship can cover and impact upon fuel efficiency. However, a large motor would produce too much noise. “Acoustic quietness is probably higher up than fuel efficiency, because if it doesn’t deliver good usable data it doesn’t matter how fuel efficient it is,” he says. To resolve this conflict they have opted to use a submarine motor that is almost silent running and will deliver the speeds and fuel efficiency required.
Shipping rules and regulations are stringent in the Antarctic and can put restrictions on the design of a polar vessel, says Bremner. The International Maritime Organization is developing the Polar Code, which will stipulate a mandatory set of specifications that ships must have to travel safely through the harsh environment of the waters surrounding the two poles. “For example, you now must have systems on board that process the ballast water – which stabilises the ship – that you have taken on board from other regions,” Bremner explains.
“You don’t want to take 10m3 of ballast water from a grubby port and dump it into the seas around the Antarctic and risk contaminating the entire region.”
This has also meant ensuring that ‘void spaces’ that fill with water if the ship’s outer shell has been punctured do in fact remain void and are not to be used to store fuel or ballast water as they once were. This has entailed increasing the size of the new ship design to incorporate a 0.75m space between the outer and inner plate running around the whole vessel, and finding other places to store the fuel and ballast water.
While it can be difficult to comply with such legislation, Bremner stresses that the BAS is in no way against the changes. Ultimately, he says, they are there to conduct research and ensure the crew remains safe and the environment unchanged in the process.
While the BAS is managing this project, Bremner says it very much belongs to the UK scientific community. In testament to this they are running a poll of scientists around the country, asking them what should end up on the final design of the ship.
With only months to go until the contract to build the ship goes out to tender, the pressure is on to perfect the design. While there are many challenges yet to come, the ultimate test will arrive when the new vessel replaces the current two-ship operation. Bremner says: “This will be the UK polar presence in Antarctica. Ernest Shackleton provides vital support to our stations. James Clark Ross has a good global reputation – it is known to be one of the leading polar vessels in the world. What we have to make sure we do is that we don’t slip from that position.”