Changing demands

The needs which had shaped this kind of design, including the desire to be able to complete the main structure within a day, and for a form of construction suited for erection by labour with no building expertise, were now no longer pressing. In fact, Casey was built by teams of trades - men over a number of years as a single project, signalling the end of the heroic do-it-yourself era. The needs of the inhabitants of the stations were also changing from the days when it was acceptable to have to battle for basic commodities of life, such as water. The need now was for more cost-effective scientific endeavour.

The Antarctic Division and Australian Construction Services began experiments in search of a more appropriate construction system. The yellow fibreglass panelled, igloo shaped Davis Biology Building was the first, but the curved shape was hard to fabricate and inefficient in internal space, without providing any advantage over adjacent "boxes" in countering snow drift accumulation.

A 1976 experiment, involving a return to timber panels sheeted with 'Hardifiex' and coated with a plastic resin, produced the Davis Power House, the Casey Trades Workshop, the Mawson Science Building (Wombat) and the Mawson Transmitter Building. Unfortunately, the panels were very heavy and again, designers failed to appreciate thermal insulation needs and water vapour characteristics, resulting in such things as the use of an aluminium window frame, which grew a thick coating of frost in the antarctic cold.

A third experiment never saw the light of day, as it proved twice as expensive as estimated because of the cost of making the fibreglass panels. However, this design provided advances in detail, stopping cold paths through the insulation and providing scaled vapour tight joints. In this design too, an inner lining of plasterboard was used as fire protection for the flammable external panels.

At this point there had been three experiments, each by different design teams. Each had fallen short of the needs of a successful system. This was felt to be due to the lack of consistent design effort, so Australian Construction Services decided to appoint an Antarctic Design Officer, and appointed Phil Incoll to the position. The task, but not the title, has stuck with Phil to this day!

Information on Antarctic buildings was not easy to obtain in Melbourne in 1976. Most of it was in the SCAR Logistics Symposium Reports from Boulder and Tokyo, supplemented by useful information in E. Rice's Building in the Norib and a number of CRREL reports. This information was gathered up by lan Holmes, the Antarctic Division's energetic liaison officer for the project. lan contributed a great deal to the AANBUS system and the station re-design project.

An obvious precedent to use for redesign of Australian stations was the elevated "wing' design for Casey, but though successful in keeping the building clear of drifting snow, this was found to have a number of defects. The elevation produced cold floors, added the cost of a high substructure, and made the building prone to noise and vibration in high winds. Two lines of buildings would not work, as the first one would bury the second, and Casey was already the length of a city block- over 200 metres. While many differ on this point, the official Antarctic Division view was that the connection of the building by the passage along the 'leading edge' of the wing resulted in lower morale than was experienced at other stations, and it was laid down that the new station designs would be made up of separate buildings.

Another way of overcoming the drift problem had to be found. Study of photographs of buildings at Davis showed that building sides parallel with the wind appeared to be swept clear of snow by the wind itself as had been evident from early days for the roofs. It was accordingly proposed that buildings should be oriented with their long sides running parallel to prevailing wind rather than across it. This would allow windows and doors to remain clear of snow if located in the long sides of the building-the most suitable place for them. A group of buildings would be arranged parallel to wind direction and to each other. Drifts would form upwind and downwind of each building but access between buildings would be clear.

The validity of the idea depends on the relatively constant direction of the strongest winds that carry the drift. These vary by no more than 30'.