Page 28 - Summer 2018

Canadian Navel Acoustics
By 1940, magnetically triggered mines had become a signifi- cant threat because they could quickly be deployed in large numbers by aircraft. The magnetic signature of a ship could be reduced by “degaussing,” applying a current to coils installed on a ship that would offset its magnetic signature. Convoys of merchant ships (Figure 1) would gather in the Bedford Basin in Halifax, Nova Scotia, Canada, to be escorted by Royal Ca- nadian Navy (RCN; see Table 1 for list of abbreviations) ships across the Atlantic to resupply the war effort in England, and the RCN was responsible for degaussing all merchant ships bound to Europe from Canada (Longard, 1993).
In February 1940, Professors G. H. Henderson and J. H. L. Johnstone from Dalhousie University in Halifax were asked to help develop degaussing techniques. By 1942, degauss- ing “ranges” were established in the Bedford Basin, Sydney (Nova Scotia), Quebec City (Quebec), and Victoria (Brit- ish Columbia). The routine work at the ranges consisted of measuring ships’ magnetic signatures while underway and calculating the current required to offset them. With rising concerns about acoustically triggered mines, a combined acoustic-magnetic range, the Hugonin Range, was con- structed in Halifax Harbour near McNabs Island.
Initially, the laboratory was located in His Majesty’s Canadi- an (HMC) Dockyard in Halifax (now Canadian Forces Base \\\\\\\[CFB\\\\\\\] Halifax). By January 1944, research had branched out into acoustic mines and submarine detection, and with a complement of about 50 staff, the laboratory was renamed the Naval Research Establishment (NRE) under the auspices of Canada’s National Research Council (NRC).
In 1947, the NRE became one of seven research establish- ments absorbed by the Defence Research Board (DRB), formed to take over the defense research effort from the NRC. In 1952, the NRE moved across Halifax Harbour into a new building that was the largest structure and the first research establishment at that time in the city of Dartmouth.
Additional establishments created by the DRB included the Pacific Naval Laboratory (PNL) in 1948, located in the HMC Dockyard in Esquimalt (now CFB Esquimalt) near Victoria, British Columbia, Canada. The PNL was charged with exam- ining naval problems not handled by the NRE and problems specific to the Pacific Ocean. Starting in the late 1950s, the PNL undertook a significant research program in the Arctic. Thus the NRE and PNL were considered “sister laboratories” studying naval acoustic problems in Canada’s three oceans.
In 1967, as part of a DRB drive to unify the laboratories through name changes, the PNL became the Defence Re- search Establishment Pacific (DREP) and the NRE became the Defence Research Establishment Atlantic (DREA; Turn- er, 2012). Most Canadian naval research was consolidated at the DREA after closure of the DREP in 1994, with only a small contingent of materials scientists remaining at the “Dockyard Laboratory Pacific” in Esquimalt (but organi- zationally part of the DREA). In 2000, the DREA became part of a new agency, Defence Research and Development Canada (DRDC), and the laboratory was renamed DRDC Atlantic. On March 31, 2018, the Dockyard Laboratory Pa- cific was closed, with the remaining materials science work being transferred to the DRDC Atlantic Research Centre. In early 2018, the staff of the DRDC Atlantic Research Centre was moved to a new building on the same site in Dartmouth as the original building from 1952, which was then demol- ished.
Over the years, research areas at the former NRE have re- mained relatively stable: mine countermeasures, harbor defense, antisubmarine warfare, torpedo defense, ship sig- natures and structures, and materials science, with the later addition of maritime command and control and informa- tion warfare.
Tollefsen – Article 2
The laboratory that began as the Anti-Magnetic Mine Of-
fice in July 1940 is now known as the Defence Research and
Development Canada (DRDC) Atlantic Research Centre.
Table 1.
Abbreviations
Term
Definition
CAT
Canadian Anti-Acoustic Torpedo
CCGS
Canadian Coast Guard ship
CFB
Canadian forces base
CRT
Cathode ray tube
DRB
Defence Research Board
DRDC
Defence Research and Development Canada
DREA
Defence Research Establishment Atlantic
DREP
Defence Research Establishment Pacific
F0
Pressure wave
FH
High frequency
FL
Low frequency
HMC
His/Her Majesty’s Canadian
NRC
National Research Council
NRE
Naval Research Establishment
PNL
Pacific Naval Laboratory
RCAF
Royal Canadian Air Force
RCN
Royal Canadian Navy
RIP
Remote Instrument Package
RN
Royal Navy
VDS
Variable depth sonar
26 | Acoustics Today | Summer 2018