Projects
Protecting Scott Base
Fire protection at Scott Base has been upgraded with a state-of-the-art detection system based on equipment designed and manufactured by Lower Hutt firm Pertronic Industries Limited.
Scott Base is New Zealand’s main Antarctic settlement, accommodating up to 85 people in summer and 10-15 in winter. Fire is a major concern for Antarctica New Zealand, the government agency that runs the base. The polar air is very dry, so fire can take hold quickly. The loss of a building means the loss of that function because there’s very little redundancy. There’s only one kitchen, one vehicle workshop, and so on. A significant fire could seriously hamper New Zealand’s Antarctic science programme.
The fire risk was highlighted in May 2009 when an A-frame hut five kilometres from Scott Base was burned down during routine maintenance. Two Scott Base staffers had changed the fuel tank for the hut’s kerosene heater. When they tried to start the heater, the small amount of fuel used for priming the heater flashed over and ignited a nearby container of fuel. The fire spread rapidly and with the hut’s fire extinguishers affected by the extreme cold, there was no chance of saving the building. Commenting on the fire in its 2009 annual report, Antarctica New Zealand said: “Fire remains our greatest hazard when operating in the cold, dry and windy conditions of Antarctica.” The A-frame was built in 1970 for the United States Antarctic Program, and acquired by New Zealand in 1985. Until the fire, it was used for field training and recreation.
Located at the southwestern tip of Ross Island in McMurdo Sound, part of the Ross Sea, Scott Base is one of the world’s remotest settlements. Although it is only three kilometres from the US Antarctica Program’s McMurdo Station (summer population >1000), there’s no guarantee the road will be open. In bad weather, visibility can fall below thirty metres and winds can reach 185 kph. Scott Base personnel avoid travelling in these conditions.
The base was built in 1957 to support New Zealand’s contribution to the Commonwealth Trans-Antarctic Expedition and the International Geophysical Year. Beginning in 1976 a reconstruction programme has seen it extensively rebuilt, with only three of the original buildings still standing. Most of the base’s heavily-insulated buildings are linked by covered walkways, and the main complex is maintained at a temperature warm enough for normal casual clothing.
Pertronic F120A fire alarm control panel at Scott Base
Self-sufficiency is mandatory for such a remote settlement. Scott Base has its own water, wastewater, power, transportation, and domestic systems. It also has workshops and staff capable of maintaining these systems, as well as scientific equipment essential to its work.
According to Peter Brookman, Facilities Engineer at Antarctica New Zealand, the base’s fire strategy depends on stringent fire prevention measures backed up by “early detection and massive, rapid response.” Antarctica New Zealand has been upgrading Scott Base’s fire protection systems since the mid 1990s. Works Consultancy Services analysed the systems in 1995, and concluded that although they were adequate from the “life safety” perspective, there were opportunities to reduce the fire risk and minimise the consequences of any fire that did break out.
Based on these recommendations, as well as regular reports by Cosgrove Major Consultants, Antarctica New Zealand initiated a capital investment programme. The latest developments in this programme were the new fire alarm, and the installation of a centrally-reticulated sprinkler system with duplicated pumps.
An important feature of the new fire alarm is its ability to precisely determine the location of a problem. The system is designed around a Pertronic F120A alarm panel. It can be triggered manually, by call switches distributed around the base, or automatically by a network of smoke detectors, and by sensors in the sprinkler system.
Almost all smoke detectors are “analogue addressable” types. Each detector has a unique address, allowing the panel to identify each active detector by location. The sensors measure the level of smoke. If it exceeds a predetermined threshold the control panel triggers the alarm. Some areas have specialised analogue addressable detectors. For example, hazard areas have “System Sensor” intrinsically-safe units, and workshops have “Vesda” aspirating detectors. Pertronic Industries Managing Director David Percy explains that “aspirating systems work by drawing air from the protected areas through a system of pipes and filters to the smoke sampling unit.”
VESDA detector at Scott Base
Some outlying buildings retain existing conventional detectors which have been connected to the new panel.
The sprinkler system uses traditional heat-sensitive sprinkler heads. Flow switches in the water pipes allow the panel to identify active sprinklers.
The new fire alarm was designed and supplied by Christchurch-based Fire Fighting Pacific and installed by Scott Base staff during the winter of 2008. According to Charlie Loughnan, Fire Fighting Pacific’s Corporate Services Manager, it was vital to build the system around solid, reliable components. It’s not practical to call in a service technician, partly because the call-out fee would be prohibitive, and partly because the base is practically inaccessible in winter, with McMurdo Sound frozen solid and 24-hour darkness. According to Loughnan, the Pertronic equipment fits the bill. It is based on standardised modules for which information and manuals are readily available, and the manufacturer provides excellent technical support. It’s also handy to know that if a component should ever need replacing, Pertronic is a local manufacturer that stands by its products.
Loughnan was also excited that the panel can be accessed over the internet for programming and fault-finding. While the Scott Base electrician was installing the new system, engineers at Fire Fighting Pacific used the internet interface to help answer technical questions, and to programme the system. In future, they’ll use the internet to download event logs and upgrade the panel’s software.
An engineer from Fire Fighting Pacific spent a week at Scott Base in early 2009 thoroughly inspecting the installation. Although they had supervised the project very much by remote control, it was a complete success. According to Loughnan, the internet interface was central to that success.
Alongside the fire alarm upgrade, Antarctica New Zealand also revamped the firefighting system. In 2007 they installed a 100 mm water pipe connecting the existing sprinkler system in each building to a pair of water supplies. One supply comes from four 40,000 litre tanks which also supply potable water to the entire base: This is never allowed to fall below 40% of capacity. The other supply comes from a tank alongside the recently completed Hillary Field Centre, one of the base’s largest buildings. (This supply is not treated for human consumption.) There is always at least 105,000 litres of water available for firefighting. Both water supplies are heated, and both are fed from a reverse osmosis desalination system.
In 2009 the Hillary Field Centre’s existing diesel pump was supplemented with a second pump. Either pump can supply the entire sprinkler system. They burn Antarctic-grade aviation kerosene, because ordinary diesel tends to crystallise at sub-zero temperatures, rendering it useless for polar conditions. Antarctic kerosene has a freezing point below -58 ºC.
As in any major building, occupants at Scott Base have ready access to fire extinguishers and hose reels. If prevention fails, these are the next line of defence. A burning building can also be isolated with fire doors.
Pertronic LCD display panel at Scott Base
The next line of defence is the new alarm system and the fire crew. Scott Base staff receive the same training as volunteer firefighters, and they are assigned to the fire crew on a roster system. Using the new alarm system, the fire crew can quickly determine where the fire started and where it is going. Seven LCD display panels strategically located around the base identify which sensors have been activated, in chronological order. There’s no need to assemble at a fire station. They can respond to a fire in as little as two minutes.
This represents a dramatic improvement over the old system. Each building had its own water supply, capable of running the sprinkler system for about ten minutes. Before tackling the fire, the fire crew’s first task was to connect the burning building’s water tank to the base’s water supply via a 50 mm hose and a fire pump.
Extreme climates often raise important engineering issues. But, contrary to what might be expected, temperature at Scott Base was not a major issue. Although many electronic devices are not specified for temperatures much below -10 ºC, Scott Base’s permanently heated buildings eliminate low-temperature problems.
Much more important was the challenge of supervising a complex project over such an enormous distance. The system was installed during the winter, when Scott Base almost totally cut off from the outside world. According to Loughnan, excellent documentation and ready access to the manufacturer’s knowledgeable engineers were critical success factors.
Scott Base is central to scientific efforts to understand the global environment, as well as the ecosystems and resources of Antarctica. This work involves a significant on-going financial investment by New Zealand taxpayers, in one of the world’s most forbidding locations. The new fire detection system will improve the security of the Base and its work.
This article first appeared in e.nz magazine, September 2010.