
Military necessity has often driven engineers and construction crews to innovate. This was certainly the case when the US military faced the challenges of building in arctic environments after, in the 1950s, it decided to extend the distant early warning line of radar bases to the east through Greenland.
The US established several air bases there during World War II, but its strategic value increased during the Cold War, with its proximity to the Soviet Union. There was much activity at Thule Air Base, the northernmost outpost, which was massively expanded in 1951 when a US Navy armada delivered a contingent of 12,000 personnel and 300,000 tons of cargo in a secret operation .
ENR editor-in-chief Waldo Bowman visited several bases in Greenland in 1957. His resulting cover story outlined many of the construction challenges and solutions.
The permafrost had to be insulated to prevent foundation damage when it thawed. About 3 feet of gravel fill was placed to cover it, with a 6-inch thick concrete pad as the floor under the air ducts. Open at both ends, these allowed cold air to flow beneath the buildings and insulated the permafrost from the heat inside. The precast concrete structure made the structures rigid enough to withstand strong Greenland winds. Schokbeton, based in the Netherlands, supplied a new type of concrete that was denser and stronger. To isolate the walls of the building from heat transfer, they were placed outside the frame.
ENR Editor-in-Chief Waldo Bowman visited the sites of several US military installations in Greenland in 1957, including some remote bases carved directly into the ice.
Photo from the ENR Archive
Ventilation was another challenge. Moisture from the internal vapor pressure froze inside the precast panels during the cold season and melted during the thaw, causing “indoor rain” inside the buildings. To avoid this, the exterior aluminum roof panels were replaced with plywood and tar paper held together by wooden slats, allowing the roof to breathe externally and dissipate vapor.
Thule Air Base, located on a shingle coastal strip in northwest Greenland in front of the edge of the ice sheet that covers 80% of the island and is up to two miles thick in places, hosted a fleet of strategic bombers. The edge of the ice sheet had ice cliffs several hundred feet high, with falling chunks and cascading meltwater waterfalls in the summer.
Bowman also visited the most remote US base, an unnamed weather and warning station 250 miles from Thule in the center of the ice sheet. Operated by the US Army’s 1st Engineer Arctic Task Force, the base’s mission was to study the ice itself and determine how to establish bases in such an alien, windswept environment. Bowman described camp buildings made of sections of 18-foot-diameter corrugated pipe buried in the snow, accessible by ramps or vertical shafts. He also described how a Swiss-made snow plow dug trenches to cover them.
These activities culminated in 1959 with the construction of Camp Century, located on the ice sheet 150 miles east of Thule. Built over a short summer, it consisted of a network of 23 interconnected tunnels totaling 9,800 feet to support a contingent of up to 200 soldiers. The cut and covered tunnels were dug snow trenches, lined with corrugated metal and covered with snow. The site, powered by a small nuclear reactor, appeared to be a scientific research base. But it was actually a preliminary camp for Project Iceworm, a planned network of nuclear missile launch sites that could survive a first strike. Within a few years, moving snow compressed the tunnels, forcing the base to be abandoned in 1967. No missiles were ever placed in Greenland.
At both Camp Century and the unnamed research base, the ice sheet was drilled to obtain continuous core samples, with various scientific instruments lowered into the holes to take readings. In 1966, a team from Camp Century successfully drilled 4,551 feet, probably the deepest ice core sampling at the time. The samples are now stored at the National Science Foundation Ice Core Facility in Lakewood, Colorado, and continue to provide valuable data to scientists studying how climate changes over time, as the cores contain a long history of greenhouse gas concentrations. greenhouse effect and volcanic and solar. activity
A record wooden structure
Another example of military necessity driving a precedent-setting project was the Air Force Laboratory’s Transmission Line Aircraft Simulator, or ATLAS-1, a giant wooden structure better known as the Trestle, which it was located at Sandia National Laboratories near Kirtland Air Force Base in New York. Mexico It was part of a device to test the ability of military aircraft electronic systems to withstand electromagnetic pulses generated by nuclear weapon detonations. The structure had a 386-foot-long, 51-foot-wide ramp that led to a 200-foot-square, 125-foot-high platform within a natural depression. Wood was used for construction, as the metal would direct pulses away from aircraft and its height prevented ground interference.
Douglas fir and southern yellow pine were chosen for their tensile strength and weatherability, with 410,000 pieces of wood laminated with glue into 15,000 members and bolted together. Quality control was strict. “Each piece of lumber is mill-dried and inspected for moisture content before being planed and treated,” said a 1977 ENR article. Some members were 126 feet long and 52.5 inches deep and contained 10,000 feet of timber. “As an example of the tight tolerances, the largest members could not deviate more than 1⁄4 inch in any dimension,” ENR said.
Between 1980 and 1990, military aircraft were towed to the deck of the trestle and bombarded with electromagnetic pulses, but the test results are classified. Testing ended in 1991 due to the increased availability of much cheaper computer simulations. Trestle, which is still standing, is considered the largest wooden structure in the world at 6.5 million board feet.
Fallout shelter construction
The Cold War threat of nuclear weapons sparked public and governmental debate over the issue of fallout shelters. Unlike blast shelters that were designed to withstand the force of a nuclear detonation, fallout shelters were simply meant to limit exposure to the radioactive fallout that would later cover the area.
Probably ENR’s first editorial on the subject, titled “Why Build Large Bomb Shelters?” was written in 1951. “A study of the plans proposed by municipal officials to protect urban populations against bombs should make it clear that only relatively few people can be accommodated in community-owned facilities,” he said. “Consequently … it does not seem logical to build a few large bomb shelters with public money.”
The editorial stated that even if large shelters could be built, “only a few people would be able to use them. In the estimated time available between the first warning of an imminent air attack and the dropping of bombs (between 8 and 15 minutes), it would be impossible to empty large office or apartment buildings and transport tenants… Panic would probably kill more people than bombs, if that was tried.”
These and other limitations led Congress to direct the Civil Defense Administration to guide local governments and provide technical information, but not to participate in the actual construction of shelters. The ENR reported in 1956 that the agency planned to examine existing structures that could serve as fallout shelters, investigate ways to build fallout protection into existing buildings, and incorporate shelters into new federal buildings, which only it represented an additional cost of 2%.