The modules feature communication lines connected to towers and steel frames that allow them to glide easily over the snow. © Sam Burrell/British Antarctic Survey
The British Antarctic Survey has opened the Halley VI Research Station, a massive facility that can climb out of snow and ski to a new location.
February 12, 2013—Antarctica is one of the most foreboding places on earth for a construction project. Temperatures dip to nearly -70°, exacerbated by wind gusts of up to 100 mph. The continent is sealed off by treacherous conditions for nine months of every year. The sun does not rise above the horizon for 105 days in winter.
But Antarctica also provides unparalleled opportunities to research such pressing ecological issues as climate change, pollution, ozone depletion, and sea level rise. And so earlier this month, the British Antarctic Survey (BAS) brought the new Halley VI Research Station into full operation, the next step in a 50-year history of research.
Planning for the new research station began in 2005, when AECOM, in London, and Hugh Broughton Architects, in London, were selected in a design competition from among 86 entries to design and engineer the facility. The project presented formidable challenges.
The site is remote, even by Antarctica standards. Snow that falls at the site never melts, burying stationary objects. The ice shelf beneath the facility is moving, and eventually objects are pushed out to sea. This meant that the BAS wanted a structure that could be lifted out of deep snow and also moved. Finally, the supply route to the site crosses an ice shelf with a strict weight limit.
“On the one hand, because of the remoteness and the climate—you only have approximately 12 weeks within which you can construct anything—you would say you want to prefabricate as much as possible,” says Peter Ayres, BEng, CEng, MICE, MIStructE, the director of building engineering for AECOM. “On the other hand, you have a logistical supply route that requires you to move materials across fragile sea ice, and that means there is a weight limit on the size of material you can pull in.”
The Halley VI station comprises a large, red, central module and
seven smaller blue modules. The central module houses most of
the research functions, as well as recreation spaces, a kitchen, and
a dining room. © Antony Dubber/British Antarctic Survey
“That gives you competing restrictions on what you can do,” Ayres adds. “To some degree, one of the biggest challenges in the design was how you work between those two restraints to get an optimum solution.”
Materials brought across the sea ice are restricted to 6 metric tons, and are transported via large sledges, which also restrict the overall size of what can be transported. The solution the design team developed to overcome these challenges employs modular units resting on large hydraulic legs fitted with skis at the foundation.
The skis eliminated the need to utilize the transport sledges, which allowed the team to design units that weigh 9.5 metric tons rather than 6. This was the key that enabled the team to build the large, lightweight steel space frames at a facility in South Africa, and then transport them to the site.
The station comprises a large central module and seven smaller blue modules. The central module houses most of the research functions, as well as recreation spaces, a kitchen, and a dining room. The central module is bright red and is approximately 5,155 sq ft. The blue modules contain sleeping quarters, offices, laboratories, and energy plants and are approximately 1,636 sq ft.
The modules are connected with modified seals commonly used in the transportation industry. This enabled the team to save the time and expense of developing a connector and then the necessary machining tools to manufacture them.
“[Many elements] on the project are transfers of technologies from other industries that you would not normally associate with buildings,” Ayres says. “So we connected the modules together using connectors similar to those used in the train and bus industries. Essentially it was those, slightly modified for the cold climate by injecting silicone into the rubberized sealants. “
The station is the sixth the BAS has developed in Antarctica. The first four were buried and were eventually crushed beneath the weight of accumulating ice and snow. The driving goals for Halley VI were to minimize the environmental impacts while giving it as long a life span as possible. That required a station that could both be raised above the mounting snow pack, and moved to avoid the danger of ice calving.
The ski foundations enable Halley VI to be skied to a new, safer
location to avoid piling snow and ice calving. © Hugh Broughton
“The legs are giant hydraulic rams,” Ayres says. “The whole building sits on the hydraulic rams. And then, on an annual basis, the whole thing can mechanically climb up out of the snow.”
To accomplish this, a two-person team will work in tandem. One person will raise a single leg and the ski foundation out of the snow. A second person will use a bulldozer to fill in beneath that leg with new snow pack. The process will be repeated with each of the four or six legs, and each of the modules. The process should take less than a week.
“In previous generations of Halley, it has taken a whole steel crew 12 weeks to jack the building up every year,” Ayres says. “The foundations themselves are giant skis,” he adds. “That means that periodically, as the ice shelf moves, and you want to go to a safe location, you can lower the building through the hydraulic jacks onto their lowest point, then you strap the legs together, hitch up the building to some bulldozers, and you literally ski it to a new location.”
The team is confident in the process because they used it to place the facility at its current site. Halley VI was built at the site of Halley V, then towed 10 km inland to a site less at risk for an ice calving.
“We often describe it as a visitor, not a resident,” Ayres says. “It’s a very fleet of foot building.”
The strict weight limit meant that completed units couldn’t be constructed in South Africa and delivered to the site. Instead, the frames were delivered and the cladding and other elements installed on-site. The team, however, assembled each unit fully in South Africa to make sure that every element was perfect.
“What you can’t do is arrive in Antarctica and find that one of your cladding panels doesn’t fit, because there is nowhere to get it fixed. In fact, that really paid dividends,” Ayres says. “When we made the big red module, one of the panels when it came from the factory didn’t fit. It was slightly oversized. We were able to take it off, take it back to the factory, and in a couple of days repair it. Took it back, refitted it, it all worked fine, so that when we got to Antarctica, everything went smoothly.
“Had we not done that test, then we would have lost a whole season taking that panel away and bringing it back,” he added.
Because conditions are harsh at the Halley site, the design team worked to prefabricate as much as possible into large, complete, easily assembled components. Cladding was created with doors and windows encapsulated at the factory. Bedrooms, bathrooms, and the kitchen area were shipped to the site complete.
“When you are actually building there, it’s difficult because you have to wear warm clothing, you have to wear thick gloves to keep warm,” Ayres says. “If it is windy, you are limited in what you can do. If you get whiteout conditions, you lose work. So we try to design things that once they got to site were assembled. No small bolts. Everything clips together. Or [we use] very large bolts so that you can handle [them] easily, and not be fumbling around in the cold with numb hands.”
The BAS traces its roots to Operation Tabarin, a World War II mission that sought to keep Axis ships out of Antarctic waters. The mission included a scientific research component to discover more about the biology, geology, and weather of the region.