Fessenden and Boyle: Two Canadian Sonar Pioneers

Abstract

Reginald Fessenden developed voice-modulated radio in the early 20th century using special alternators and microphones capable of handling kilowatts of power. When the Titanic struck the iceberg in 1912, Fessenden, then in Boston, developed an audio-frequency acoustic transmitter-receiver, which he used to detect an iceberg at two miles. When the “Great War” began, UK interests turned to detecting submarines. Ernest Rutherford, on behalf of the Bureau of Investigation and Research (BIR), invited former students A. B. Wood, and R. W. Boyle, to join the anti-submarine effort. Fessenden was also consulted. The team detected submarines using Fessenden’s device but experienced difficulty determining target bearing. After consulting Paul Langevin, Boyle agreed that quartz transducers operating at ultrasonic frequencies should provide a solution. Boyle then developed the UK Type 112 “ASDIC” which was being fitted to Royal Navy warships just as the War ended. Boyle returned to the University of Alberta after the war and continued work in ultrasonics. In 1929 he was appointed Director of Physics at Canada’s National Research Council. There he established an Acoustics Section, and during World War II started a scientific activity in Halifax, NS, which later became the Naval Research Establishment.