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Cold War Radar

Introduction to the Line

Radar lines.jpg

1957 image of the Canadian radar lines.  Note the DEW Line which is furtheset north

By the 1950s the Pinetree and Mid-Canada Line (MCL) were no longer sufficient for the coverage required for North America's defence.  Warning time continued to decrease, by 1961 giving less than 15 minutes.  As the Soviet Union advanced in their own technology, more had to be done to protect the continent.

The DEW Line, or the Distance Early Warning Line was approved in 1954 by both countries and was fully an American project.  It was built by the the United States and American staff was present at the stations.  The expense, covered by the Americans as well, was actually low through the use of a new technology, aural presentation of radars. 

Transair and Nordair supplied the Line, Federal Electric kept it up, and Western Electric constructed it.

It was located 600 miles north of the MCL and included extensions from the American Navy.  It also connected to Britain, and thus NATO, with the Greenland-Iceland-United Kingdom Barrier. 

The Line, located along the 69th parallel, would give more than 4 hours warning time and allowed 70% of American planes to get in the air before an attack.

It was built from 1955-1957 with Doppler radars located every 80 kilometres and traditional long-range radar and rotating antennas every 160 kilometres.  There were six main stations each 800 kilometres apart.  All of the information from both radar types was displayed on the same radar screen.

The Line became active in 1957 with 57 ground radar stations, connected with naval and airborne radars, including the Navy’s Airborne Craft Barrier in Newfoundland.

Even with the creation of the DEW Line, not all of Canada was covered by radar.  There were islands in the Arctic that were outside coverage and there was a gap in between the DEW and Pinetree lines.

By 1963 all  31 gap filler radars of the Line were closed.  Throughout the 1970s and 1980s some of the sites were fixed up, but the entire Line was shut down by 1987-88.

Alarm System:

The Lincoln Lab was to create an alarm system so that the DEW stations did not always need to be manned.  The time limits did not allow them to create a whole new radar.  Instead they combined the AN/TPS-1D which was a light search radar with an antenna by Bell Telephone Labs to make it reach father.  This then was called the AN/FPS-19.  Some issues had to be worked out though such as the dealing with the cold and making the alarm audible to human ears.


The Dew Line
Introduction to the Line