British Antarctic Survey research station: secrets behind the design

• How to design the services for a research facility in the harshest conditions on the planet.

• Detailed descriptions and diagrams for water management, power generation, lighting, drainage and keeping the station on top of the snow.

• A services engineer’s site visit to the bottom of the world.

• Sections detailing the construction of the research station modules, mechanical services and energy strategy, provision for occupants’ wellbeing.

1 — Construction of the latest British scientific research station in Antarctica is already underway in South Africa

Faber Maunsell and Hugh Broughton beat two other shortlisted teams (BSj 04/05) to win the competition to design the British Antarctic Survey’s (BAS) latest research station, Halley VI, with an impressive design concept involving a series of modules, all sat on giant skis that enable them to be easily relocated.

But there isn’t much time to turn this vision into a reality. BAS wants to move out of its existing 20-year-old base, which will be dismantled and shipped away, by 2010. This means that the construction team has just two austral summers to get the job done. Work will begin in the 10-week period that will be the austral summer of 2008, when temperatures should rise to a balmy 4ºC. Contractor Morrison will need to ensure that the main construction modules are assembled and made weather tight before winter sets in and the contracting team must leave for home. One thing on the builder’s side will be the 24 hours of daylight that occur throughout the summer months, allowing teams to work in shifts around the clock. The fit-out will then take place during the 2009 summer, before BAS occupies the base the following year.

To meet this tight schedule and combat the pressures of the harsh working environment, prefabrication is essential. Morrison is working on prototype modules in Cape Town, which are being assessed for buildability. The plan is for these to leave South Africa this December and work their way by special ship, designed to be able to break through the ice, to a position just off the Brunt Ice Shelf, where the main components will be unloaded onto sledges and towed to the Halley V site. As Michael Maslin, regional director with Faber Maunsell, explains: “Assembly will take place at Halley V to take advantage of the life support systems already in place.” The 60-strong construction team required will be housed in the existing facilities, as well as a temporary accommodation building.

The weight of the loaded sledges cannot exceed 9 tonnes, the maximum that can be supported on the sea ice, and this is one of the limiting factors for the degree of pre-assembly. “We would have liked to prefabricate all modules and shipped them directly onto the continent fully fitted out and commissioned,” says Maslin. “But the route to site is across the sea ice and experience shows that the maximum weight we can haul off the ship is 6 tonnes on a sledge or 9 tonnes if the cargo has its own skis.” The plan therefore is to build and fit the lower space frame superstructure of the modules with transit legs and skis ready for towing to the site, maximising the degree of prefabrication.

Once at Halley V, which is 12 km away from the new site for Halley VI, floor cassettes, containing the bulk of the services, will be lifted into position by crane and underfloor cladding will be installed. Sealed prefabricated pods and any large prefabricated mechanical and electrical items will also be craned onto the newly-created platform before the portal frame superstructure steelwork will be lifted onto the pod and fixed into position.

Lightweight glass-reinforced plastic cladding panels will be bolted to the steelwork. They will also be installed with mechanical fixings to enable easy removal when the station is decommissioned. The panels are an example of technology transfer being used on Halley. Used on commercial airlines, they consist of closed cell polyisocyanurate foam insulation encapsulated in GRP, and finished with a layer designed to minimise discoloration, resist UV and the abrasive impact of wind-driven snow and ice. The airtight system provides U-values of 0.113 W/m2K (1.1 W/m2K for the windows).

External fixtures, such as roof decks and ladders will also be fitted and any openings sealed to make the module weather tight and ready for moving to its winter position where it will be left until work recommences in 2009.

During the second summer, the main fit-out of the modules will take place. All scientific equipment will not be commissioned until BAS has occupied the station, when fixtures, fittings and services will also be installed.

The construction team for the first two summers will consist of about 60 workers, reducing to 25 in the final summer.

The completed modules will weigh about 80 tonnes each. They will be moved to the Halley VI location using D5 Caterpillar bulldozers over a prepared snow surface.

2 — Mechanical services and energy strategy

Halley VI is primarily a survival module for its occupants and as such it needs to be as self-contained and as self-sufficient as possible. Comparisons have been drawn with NASA’s lunar landing craft. “It’s similar to the lunar excursion modules used in the 1970s, only ours is bigger, assembled in situ and isolated every year for 10 months during the austral winter,” says Maslin.

Halley VI will differ from its predecessor in that it can be easily relocated. The design team’s approach has been to create a series of semi-autonomous modules that sit 4.5 m above the snow on giant skis. When the ice shelf calves throughout the building’s 20-year design life, it will be possible to disconnect the modules and tow them several kilometres to a less vulnerable site.

The hermetically sealed modules will plug together to form two main platforms. The northern platform provides the principal living accommodation, including a two-storey ‘mother ship’, housing the main social spaces, while the southern platform accommodates the science modules. A pedestrian and services link bridge connects the two. This separation into two distinct zones creates a refuge in case of catastrophic failure of one platform or an energy module.

Rather than having the modules clustered around the ‘mother ship’ as in the original competition design, the modules will be placed in a line, perpendicular to the prevailing wind. This in-line format minimises snow management by reducing the amount of drifting and snow build-up.

The entire design of the base has to comply with the new Antarctic Environmental Protocol, which establishes strict limitations on pollution and waste disposal – ultimately everything delivered to the continent must be removed. From an energy point of view this translates into a lean design.

“As with any project, we firstly reduced energy consumption to a minimum and only then looked at how ‘clean’ and green’ the generation could be,” says Maslin. The main source of electrical power and heating will come from packaged CHP generators running on AVTUR aviation fuel.

With Halley VI the decision has been made to switch to a series of smaller CHP units that can more closely match supply to demand and will be easier to manhandle and replace if the need arises.

The other key characteristic of the services is simplicity. “During a meeting with a Houston-based consultant working for NASA on its manned mission to Mars project, we were told that parts of the current international space station were no longer working because the large number of spares required just couldn’t be delivered or stored. As the space station has been enlarged, the discipline of keeping things simple has been lost,” Maslin recalls. So the number of key components has been rationalised to cut down on the number of spares that have to be carried and to simplify maintenance.

3 — The occupants’ wellbeing

The Halley research station is one of the most isolated facilities in the whole of Antarctica. Sitting 15 km in from the edge of the Brunt Ice Shelf,

weather conditions are extreme. Halley VI will be home to 52 scientists and support staff throughout the two-month austral summer, reducing to just 16 over the winter period. It’s these ‘over-winterers’ who will have to endure the most gruelling conditions, including complete darkness for 55 days.

With this in mind, the artificial lighting needed to satisfy more than simply issues of energy consumption, life expectancy and robustness. It also had to help retain the best possible natural physiological balance and psychological wellbeing of the base’s occupants.

“In order to emulate the beneficial affects of natural daylight, many of the base’s internal work areas will have the ability to be illuminated to quite high levels of cool artificial light, especially important in winter months when no natural daylight is available through the modules’ windows and skylights,” says Martin Valentine of Faber Maunsell’s specialist lighting group. The use of high colour-rendering, cool-daylight lamp technology combined with warmer sources and simple manual and automated controls aim to maintain a controlled balance throughout the changing days and months.

Living areas and bedrooms use far warmer lighting from a number of discrete fittings, and illumination levels, although manually controlled, will be significantly lower in these areas of the base. “This, together with the bases’ colour palettes, helps to visually differentiate between work and living environments,” says Valentine.

Given the Antarctic’s severe seasonal variation with regards to natural daylight and sunlight, and the different shifts and tasks that the occupants have to manage, creating changing lighting to simulate a typical day for everyone during the long winter months becomes very difficult. In normal commercial buildings this is relatively easy, but the extra cost, amount of equipment and energy consumption in this wilder environment was prohibitive for Halley.

However, research has shown one of the key times to beneficially ‘charge’ the body with light is first thing in the morning. So every bunk in the base is provided with a custom wall-mounted bedhead ‘SAD’ panel with local control, which allows occupants to receive up to 10 000 lux of ultra-blue 17000 K daylight-coloured light as part of their morning alarm. The panels of light will operate on a dawn setting, reaching full brightness slowly, and assist in the suppression of melatonin and production of serotonin, two of the key chemicals in the body that determine the natural circadian rhythm.

One other idea incorporated into the design to make life more bearable is a hydroponics facility for growing fresh salads and vegetables during the winter months.