Special Wireless Stations, 1941-1947

This briefing book is about Canada’s “Special Wireless” and direction finding (D/F) stations. These activities fall under the category of what the Anglo-American allies called “Y” intelligence. Edward M. Drake, an important figure in Canadian wartime and postwar signals intelligence, once defined “Y” as “the interception and study of enemy signals and traffic transmitted by wire or by wireless for the purpose of obtaining intelligence.”¹ Canada’s wartime “Y” efforts centred around pulling radio messages from the air and finding meaning in these various signals which could give the Allies an advantage in the war. This briefing book is the third instalment in a Canada Declassified series on wartime signals intelligence, and its content is drawn from some of the same archival files as the first two.

Check out the other two briefing books in this series: Keeping an Eye on the Americas and Wireless Weirdness.

This briefing book serves as a chronicle of the physical infrastructure, sites, and technologies which were required to keep the Canadian signals intelligence machine running throughout the Second World War and into the postwar world, rather than focusing on the content of wireless intercepts or the process of making these readable and meaningful.

1. ""Y" Work by Allied Nations," by Major E.M. Drake, April 6, 1943. Library and Archives Canada box RG24 volume 29163, file WWII-5 pt. 1.

Rockcliffe: Special Wireless Station No. 1

Rockcliffe, the Ottawa-based Special Wireless Station, existed before the Second World War started. Before Canada entered the war in 1939, it was referred to as the “Experimental Wireless Station,” “Signals Experimental Station,” or the “R.C. Signals [i.e., Royal Canadian Corps of Signals] Experimental Station.” The term “Special Wireless Station” only came into use in 1941. Canadian military personnel took care to never use the terms “intelligence” or “wireless interception” to describe the activities of these “experimental” or “special” stations, to protect the secrecy of the work being performed.

Over the course of the war, Canada would build a handful of other Special Wireless and D/F stations across Canada. For example, Special Wireless Station No. 2 was in Grande Prairie, Alberta, and Special Wireless Station No. 3 was in Victoria, British Columbia (CDWI00128). Special Wireless Station No. 1 was eventually moved from Rockcliffe to Leitrim (just outside of Ottawa), where it remained and continued to serve a signals intelligence purpose after the war.