Building Envelope of South Pole Station

The South Pole Station is among the highest performance buidings in the world with regards to conservation of heat energy. The building incorporates myriad technological approaches to capturing and reusing heat from appliances and mechanical processes within the building, but none of these efforts would be effective if the building envelope itself were not so well-insulated.

The building envelope is made of conventional structural insulated panels, a residential building product composed of two sheets of Oriented Strand Board (OSB) sandwiching a slab of Expanded Polystyrene Insulation (EPS). The boards are laminated onto each side of the foam core and work in tandem with the foam as a stress-skin panel--an engineered assembly which is stronger than the sum of its parts. When used on the horizontal plane as part of a floor or roof assembly, a stress-skin panel works the same way as an I-beam with the top panel in compression and the bottom panel in tension.



These high-performance modular building blocks are a highly effective material in polar regions since they are lightweight, very quick and easy to assemble, and combine structure, insulation, and an integral vapour barrier in a single element. The South Pole Station utilizes SIPS for its entire building envelope as both a structural and an insulative element for floors, walls, and roof.

WALL SECTION OF SOUTH POLE STATION


Panels typically come in four foot wide sections with custom lengths of up to sixteen feet and foam core thicknesses up to 11.25". The panels are joined together by means of a spline which fits into both edges of two adjacent panels as a bridge to mechanically fasten them together. The fact that the resulting wall assembly is completely solid with no voids prevents air inflitration and offers a higher performance wall assembly in terms of fire resistance, strength, durability, and thermal resistance.

Link to manufacturer of SIPS for Amundsen-Scott South Pole Station:

http://www.enercept.com/

Heat

Machinery stops working at a temperature of approximately -40 degrees Celsius. Aircraft stops working at a temperature of approximately -45 degrees Celsius. Symptoms of hypothermia begin to appear when a human's core body temperature drops one or two degrees Celsius. With the South Pole reaching temperatures downwards of -60 degrees Celsius during the winter, it comes as no surprise that any structure that is to survive within the Antarctic climate must be designed to accommodate such extreme cold.

The wall sections seen below show how each structure incorporates insulation in order to retain whatever heat exists inside. Although the Fram’s section is much wider, this has more to do with the fact that the hull of the ship had to be extremely strong, and therefore had to have many layers of wood. Amundsen actually worked to maximize the efficiency of the insulation while reducing the amount of space it took up. The layers of wood – especially the greenheart – also were used to make sure that ice and snow did not seep inwards and destroy the ship.

Fram Wall Section

ASSPS Wall Section

The diagram below illustrates how the insulation works in order to hold the heat inside across the whole structure. This is especially important for the Amundsen-Scott South Pole Station. Typically, a building resting on ice will emit heat from all areas, thus forming a thermal bulb underneath the building. As explained later, this leads to differential settlement. The ASSPS combats this by heavily insulating the floor and the substructure, and only having columns break through to the substructure. This means that essentially no heat is released through the floor. Once again, this will be explained in depth elsewhere.





We now understand how heat is retained, but the next concern is how it is generated. Due to technological limitations, the Fram had to use petroleum to heat the ship, and the crew made use of extremely warm outerwear when above or below deck. In the laboratory, warm air is brought in from the galley.

Roald Amundsen and his Nifty Winter Gear

The Amundsen-Scott South Pole Station took this idea of piping in warm air to a whole new level. They used heat exchangers to capture waste heat from different areas, and then moved the heat to where it was needed. This mainly takes place in the power plant, as shown below, where the diesel engines are situated.

Diesel Engine and its Waste Heat

Distribution of Waste Heat from the Power Plant

Waste heat is also captured from other areas of the building, such as the kitchen, the green room, and various electronic rooms.

Other Areas Where Waste Heat is Captured

Ice Creep

Ice creep is a phenomenon unique to polar construction in which the weight of a structure causes ice to compress and shift away from sources of pressure. The resulting differential displacement of ice beneath a building causes uneven settling and makes keeping the building level a challenge.

The Amundsen-Scott South Pole Station incorporates a variety of design elements to manage ice creep. An ice foundation reinforced with a steel grade beam is the first line of defence to mitigate ice creep by creating a solid substrate upon which to place the building supports.



Built on a 3.2 kilometre deep glacier, the station will inevitably experience differential settlement during its life cycle, despite the reinforced ice slab foundation. The building has been designed to compensate when it settles out of a level position by using hydraulic jacks integral to the columns upon which it sits. When deployed, the jacks allow for a quick and easy re-levelling of the building and allow for the integration of new sections of columns to raise the building.

Differential settlement is also addressed in the design of exterior doors. An adjustable height assembly is used to lower or raise the height of exterior doors as required by settlement or the accumulation of snow. A series of modular pieces are moved from below the door to above or vice versa to allow verstality in the location of the opening within an oversized door jamb assembly.

The station is built as an assemblage of smaller, autonomous structures or 'pods' joined by flexible joints which allow for movement of between 6-9 inches in any direction. These flexible joints are another innovative design element, similar to the passenger bays in airports when boarding an airplane. In the joints between buildings, all of the mechanical elements must also accomodate movement and are appropriately equipped with flexible sections of pipe or ducting.

Designing for the South Pole Climate

The South Pole is located on a plateau of ice about 2700 meters thick at an altitude of about 2835 meters. Due to this altitude and distance from the ocean, it has one of the coldest climates on earth. It is even colder than the North Pole which benefits from the ocean acting as a reservoir of heat.During the summer months at the South Pole (September-March), the sun is continuously above the horizon and moves in a counterclockwise circle, however, it is always low in the sky. The sun reaches a maximum angle of 23.5 degrees in December. The temperature averages at around -25 degrees Celsius in the summer and -65 degrees Celsius in the winter. The South Pole has a desert climate and as a result, suffers from extremely dry air and very little precipitation. The average accumulation of snowfall is 20cm/year. Average winds travel at around 19.8 km/h and can reach up to 88.9 km/h. These winds cause snow drifts which cause major snow build up around structures. Due to this extreme climate, there are no native residential plants or animals at the South Pole.

The new station, of course, had to take into account the South Pole's extreme conditions. It was also an improvement on the designs of previous stations.

One major issue that any structure at this location must deal with is drifting snow. Both the 1956 and 1975 stations had constant snow build up requiring the use of bulldozers to clear the snow and transport it miles away. This process of excavation was not only time consuming, but it used up considerable amounts of valuable fuel. In response to this problem, the new station is elevated off the ground by 36 hydraulic jacking columns. Also helping to minimize snow build up is the shape of the building. The structure is designed to face into the prevailing winds with the profile of an airplane's wing enhancing air flow around the building.

Due to its sloped bottom edge, the wind will also accelerate as it passes under that building helping to clear snow build up.

In the event that snow does build up under the structure, the hydraulic jacking columns are designed to raise the building up in 10 inch increments. This is accomplished by adding new column sections. The whole structure can be raised up a total of two more stories above the ice.

To allow for the shifting ice on which the station sits, connecting walkways between building modules are flexible.

For ease of transportation to South Pole, the new elevated station is made up of 4 modules which were shipped by ski-equipped LC-130 Hercules cargo aircraft. The aircraft can carry more than 40,000 pounds of cargo.

Timeline for Amundsen Scott South Pole Station

The construction of the Amundsen-Scott South Pole Station began in November 1956, to support the International Geophysical Year in 1957. The International Geophysical Year was based on the previous, smaller scale International Polar Years (1882–83 and 1932–33), and was used to join multiple nations and their scientists together. The year chosen was full of intense solar activity, and so it was decided that the participating nations would look at a variety of aspects of the earth and not just the polar regions. It allowed for scientific exchange across the world, in a time where tensions were high between the East and West (Cold War).

The Original station, completed in February 1957, lasted until 1975. Before its construction, the winter conditions at the South Pole had never been measured. As a result, the station was built partially underground as it was thought that this would protect it from the weather. However, it caused wind-blown snow to build up in the surrounding area, burying the structure further at a rate of about four feet a year. The station is now deeply buried, and has been abandoned since 1975. Its wooden roof has caved in because of pressure, and the site is now a hazardous area off limits to visitors.

Plan of the old station

The next station was built as a geodesic dome in 1975. From the 1990s on, astrophysical research took advantage of the atmospheric conditions of the South Pole, producing significant scientific results. An observatory building was dedicated in 1995. The increasing importance of these projects resulted in the increase of scientific cargo and personnel. The Dome was initially designed to house 18 people during the winter and 33 during the summer but as the infrastructure and technology increased, a number of science and berthing structure were added in the 1990s. The Dome was in use until 2003.

In 1999, a physician, Jerri Nielson, staying for the winter, diagnosed herself with breast cancer and began treatment. She trained the staff around her to help with chemo. She was stuck there for the winter months because of the extreme cold, and no planes flew in during this time. There was only one doctor, and no other trained medical staff. A Navy was supposed to drop her medical supplies but the plane couldn't land because the gear and mechanical fluids would freeze. She was evenutally flown home. Jerri Nielson died in 2009.

In 2003, the new Elevated station was built. Its design started in 1992 by Ferraro Choi & Associates, and its construction began in 1999. Important features, indicating a growth in the design resulting from experience, include a modular design which allows for an increasing station population, as well as an adjustable elevation to prevent the station from being buried in snow. (Other measures have also been taken to keep the structure from being quickly in snow. For example, an angled wall faces the wind thus increasing the speed of the wind as it passes above, causing snow to be scoured away.

It is evident that the station not only changed over time as they learned from experience, but the changing conditions also resulted in the change in design. The station had to accommodate these changes, hence the building evolved. The first station was built to support researchers during the International Geophysical Year. However, interest in Polar Research increased so a new design and a larger station were necessary. The dome facility was designed to accommodate 18 people during the winter and 33 during the summer, but over time the design couldn’t contain the growing infrastructure and technology. As a result, science and berthing structures were added in the 1990s. Finally, the elevated station was constructed to further deal with the problems of the climate and the increasing population of the station.

Timeline for the Fram

The Fram was used in expeditions between 1893 to 1912.

The Fram on Ice

It was initially designed for Fridtjof Nansen’s 1893 expedition by Colin Archer. Nansen wanted to explore the Arctic farther north than anyone before him had. To do this, he had to deal with a problem other ships were facing when venturing onto icy waters (a specific example is the Jeannette)– that the ice could crush the ship. Nansen’s idea was to build a ship that would be able to survive the pressure not solely by strength, but because it’s design would work with the ice. The idea was for the ice to push the ship up, causing it to “float” on top of the ice, unlike any other ship of the time. The Fram left on June 24th, 1893 and entered the ice pack on September 25th. The Fram stayed in the pack ice, where the ship became like a station, where the men did the analysis of the sea depth, salinity and other characteristics of the ocean. On October 13th, it survived a serious of pressure waves which had destroyed many other ships in the past. It finally emerged from the ice pack 3 years later.

Nansen's planned drift to the North Pole

Nansen's expedition

On June 24th, 1898, Otto Sverdup led a scientific expedition to the Canadian Arctic Islands. A number of alterations were carried out for this expedition. A significant change was the introduction of a new deck. Sverdrup wanted to sail through Greenland and Ellesmere island, but got stuck in the pack ice near Ellesmere island, where the ship acted as a base for exploration of the surrounding areas. They surveyed new islands, by exploring with sledges.This expedition lasted until 1902.

Sverdrup's Expedition

In 1905, a large portion of the ship’s exterior was lost in a fire in a naval storehouse.

In 1907, the ship was examined. Panelling, insulation, and parts attacked by fungus or decay were removed. Woodwork was coated with carbolineum or tar.

On June 1st, 1908, Roald Amundsen and Colin Archer inspected the ship. Amundsen wanted to be the first to reach the South Pole after he found out the North Pole had already been achieved. During the spring of 1909, the Fram was repaired and altered according to the conditions necessary for Amundsen’s expedition. A significant change was that the steam engine and the boiler were replaced by an oil-motor. Amundsen left for his expedition on August 9th, 1910. Once in Antarctica the ship settled for the winter to wait for spring to head over the ice to get to the South Pole. Amundsen was the first to reach the south pole. His expedition ended in 1912.

Amundsen's Expedition

Between 1912 and the late 1920s, the ship decayed in storage

In the late 1920s, Lars Christensen, Otto Sverdrup, and Oscar Wisting began efforts to preserve the ship.

In 1935, the ship was relocated to the Fram Museum where it now stands.

The Fram in the Fram Museum

Similar to the South Pole Station, the Fram also had to be modified as its purpose changed over time.

Fram Drawings

Plan - Nansen's Fram

Plan - Nansen's Fram

Section - Nansen's Fram

Section - Nansen's Fram

Section - Nansen's Fram

Plan - Amundsen's Fram

Plan - Amundsen's Fram

Section - Amundsen's Fram

Section - Amundsen's Fram

Axonometric - Amundsen's Fram

Amundsen-Scott South Pole Station's Purpose

The original station was set up by Roald Amundsen who reached the South Pole on Dec. 11, 1911. It was simply a tent that he set up in the spot he determined to be the South Pole.

The station today is named after Amundsen, as well as explorer Robert F. Scott and his party, who reached the South Pole Jan. 17, 1912. In 1956, the site was surveyed for the establishment of a research station for the International Geophysical Year (IGY), which was completed in 1957. It expanded so much that a new station was constructed from 1970 to 1975 and dedicated upon completion. Since then, a third station has been built, and was completed in 2008 for the U.S. National Science Foundation.

Originally built 400 m from the South Pole, the ice movement at a rate of 10 m per year is moving the station closer to the real pole. Today, it is a year-round facility for scientific projects operated by the National Science Foundation. Its location is ideal to research things like the Earth's origin, astrophysics, astronomy, and climate change. It includes living, dining, communication, recreation, laboratory, observatory, and meeting spaces. It can accommodate over 200 people, although only about 40 stay through the winters to keep the station running.

The Fram's Purpose

The Fram was a ship used in expeditions to both the North and South Poles. On the first voyage, Norwegian scientist Fridtjof Nansen wanted to test his theory of a transpolar current. He had naval architect Colin Archer design a polar vessel in 1892, and planned to let the current carry the ship to the North Pole. The Fram was initially designed for polar regions, unlike many ships at the time which were originally merchant ships. The basic design allowed the ship to be set into an ice pack to be carried by the current across the water. Most ships tried to avoid the ice, but the rounded hull of the ship allowed the pressure of the ice to push the ship up above the ice, instead of damage the ship.

Its strength was the first priority in design, as opposed to the aesthetic. For later polar expeditions, the Fram's design was altered. It was about the average size for polar ships at the time, and had enough space to store food and firewood for six years.

Nansen and his crew set sail for the Arctic on June 24th, 1893. The ship entered an ice pack on Sept. 25, at which point the engine was dismantled and a windmill was set up to provide electricity. The Fram became an arctic station, as it was used for recording data on sea temperature, depth, and salt content. Nansen also studied the Aurora Borealis.

Over the voyage, the ship proved its strength as it survived the ice and pressure waves. The trip did confirm the existence of the current, but the wind and tide played significant roles in altering the ship's path. It was used for later polar expeditions led by Otto Sverdup in 1898 and Roald Amundsen in 1910, and has been in the Fram Museum in Oslo, Norway since 1935.

Amundsen-Scott South Pole Station Architects

Ferraro Choi and Associates Ltd

The Elevated South Pole Station, under design/construction from 1992 - 1998, was designed by the Ferraro Choi architectural and engineering team. The firm, founded in 1988 by Joseph J. Ferraro and Gerald K. Choi, is based in Honolulu, Hawaii.