Eyes on the Skies - History of the DEW Line

If Soviet nuclear bombers entered Arctic airspace, DEW Liners hunched over radar screens had only a few seconds to react. Identify the aircraft. Send a warning south.

The Cold War saw a rapid acceleration of technology. Americans and Soviets raced to the moon. Computers overtook clumsy encryption machines. Intercontinental missiles replaced bombers. Eventually, satellites would handle long-distance communications. State-of-the-art one day became obsolete the next.

DEW Liners used two different systems: radar and tropospheric scatter. Radar to detect, tropo to report. The swiftly rotating radar scanners were protected by an iconic geodesic dome. The enormous tropo antenna towers served (and still serve) as wayfinding markers for Inuit travelling across the largely featureless tundra near FOX-MAIN.

For a few years, the DEW Line formed North America’s cutting edge of Arctic surveillance.

Constant Vigilance

Radar technicians (radicians) scanned the skies for Soviet nuclear bombers making their way across the North Pole, heading for Canadian and American targets: military bases, factories — whole cities, millions of people.

Two radicians operate the radar console at one of the DEW Line stations. Manning the Dew Line, New York: International Telephone and Telegraph Corporation, 1960

The job could be both stressful and boring. It involved hours staring at a rotating screen, noting every blip. All commercial aircraft were required to submit a flight plan, which was then relayed to DEW Line stations. Canadian and US military aircraft used specific signals and channels to verify their locations. The sudden appearance of an unknown, moving airborne object caused an immediate scramble in the console room. NORAD needed to know.

Overlapping Detection Zones

The DEW Line involved 61 stations, each with overlapping detection zones. If one station picked up a suspicious blip, it could verify with other operators monitoring the same zone.

Spy Planes

Both the Americans and the Soviets operated spy planes in Arctic air space. Detecting intended nuclear attack might have been the primary goal of the DEW Line, but picking up the activities of spy planes was also important.

Monitor

Radar screens are familiar from countless movies. The “arm” circles round, picking up “incoming” aircraft — or flocks of birds. Determining the aircraft’s identity, speed — height, and course was all the job of the radician.

Path Testing

Ensuring the antennas were properly adjusted was called “path testing.” Although protected by the dome, the antennas were sometimes disturbed by high winds.

Ashtray

The 1950s and 1960s were an era of open (and unregulated) tobacco use. Because their job involved high pressure along with a vast amount of downtime, most DEW Liners smoked. For those who did not, the smoke-filled, sealed working and living conditions could be unpleasant.

Maintenance

Radicians worked in pairs. While one monitored the scanners, the other conducted detailed, methodical, preventative, and corrective maintenance on the equipment.

Microphone Headset

When radicians needed to connect — to an aircraft, another station, or contacts down south — they used a microphone headset patched through the radio network.

Radar + Dome = Radome

From the radome, radio waves raced through the air to detect potential enemy airplanes entering North American airspace.

The radome at FOX-MAIN. Photo courtesy of Brian Jeffrey

While not a new technology — radar was used during the Second World War — using radio electromagnetic waves to detect airborne objects enabled DEW Liners to monitor vast expanses of land and sea. By connecting to nearby DEW Line stations, radicians could determine the position and speed of incoming objects.

Using radar in Arctic weather conditions was a challenge. The rotating radar antennas had to be covered by a lightweight structure that was both permeable and strong enough to withstand high winds, metal-snapping low temperatures, blowing snow, and heavy ice. The geodesic dome was the perfect solution.

Radar

As the radar antenna turns, it lets out a short burst of radio waves. These pulses move at the speed of light. The pulse bounces back off an object such as an airplane. From the time the pulse takes to return, the radician knows how far away the object is.

Constructing the Radome

Geodesic domes were easy to transport and construct. The structure distributes weight across the base, making the dome very strong.

The Igloo

Inuit have always known that a permeable snow-block dome — an igloo — was a strong and versatile building type ideally suited for Arctic conditions.

Geodesic Domes: Expo 67 US Pavilion

Popularized by American architect Buckminster Fuller in the 1950s, the geodesic dome became an icon of the “space age.” Fuller’s dome was a key part of Montréal’s Expo 67 display and still stands today.

Cold War Innovation: Tropospheric Scatter

DEW Line stations used tropospheric scatter technology to bounce signals across long distances and connect DEW Line stations across the Arctic.

A troposcatter antenna (right) and Doppler tower (left) at FOX-MAIN. Photo courtesy of Brian Jeffrey

Troposcatter Communication

Before satellite communications, tropospheric scatter (troposcatter) was one method of communicating wirelessly over the horizon. Microwave radio signals were sent high up into the atmosphere, bouncing off the troposphere, then back down to the receiving station. The tall dishes around FOX-MAIN were used for this.

Antennas as Landmarks

Inuit have navigated their Arctic territories for thousands of years, using landmarks both subtle and dramatic, such as mountains, lakes, and other landforms. They erect inukshuks to assist navigation. The tropo antennas, especially in the flatter lands around FOX-MAIN, continue to be an excellent wayfinding marker for everyone.

Troposcatter Antenna

Before satellite communications, tropospheric scatter (troposcatter) was one method of communicating wirelessly over the horizon. Microwave radio signals were sent high up into the atmosphere, bouncing off the troposphere, then back down to the receiving station. The tall dishes around FOX-MAIN were used for this.

For southern governments, establishing and maintaining a presence in the Arctic has been an ongoing goal — one often pursued at the expense of Inuit traditional life.

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