HAIDA'S  Sonar Control Room as it appeared  in September, 2007. (Photo by Jerry Proc)

The Sonar Control Room contains the control equipment and indicators for various sonars that were carried in the ship. Sonar is an acronym for Sound Navigation and Ranging. Prior to this term, the Canadian, British and Commonwealth Navies used the term ASDIC in reference to the Anti-Submarine Investigation Committee of 1917. HAIDA was fitted with various submarine detection equipment over the years , but at the end of her service life she was fitted with the following sets:

AN/SQS-10 Search Sonar
AN/SQS-501 Sea Bottom Identification Set
147F Depth Finding Set
164B Range and Bearing Finding Set for Ahead Throwing Weapons

The Sonar transmitting and receiving equipment was located in the Sonar Instrument Space in the Forward Lower Messdeck. Mounted on the bottom of the hull was the sonar dome which housed the transducers. This dome could be retracted when the Sonar was not being used.
 
 

This SONAR dome, known  as “HULL OUTFIT #7A” was part of HAIDA’s SONAR system and would be found under the hull about one third the length of the ship. All the SONAR transducers were mounted within the hull outfit.  The exterior of the Hull Outfit is clad with a special type of stainless steel called Staybrite. Normally, the dome is retracted when the ship is in shallow water or in harbour. When SONAR is to be used, the dome is lowered from its retracted position. It then floods with sea water, thus permitting the passage of the initial transmitted sound pulse and reception of echoes. In the above photo, the hull outfit is being displayed in the inverted position.  (Photo by Jerry Proc)

To hear pinging from a real sonar, select this link  (168 kb wav file). What you are hearing consists of a transmission, followed by an echo after 3 seconds. This is repeated a second time. It therefore takes 1.5 seconds for the sound to reach the target. The returning echo after 3 seconds corresponds to a contact approximately 2,400 yards away (Calculation: The speed of sound in water is approximately 4,800 feet per second  multiplied by 1.5 seconds = 7,200 feet or 2,400 yards). File courtesy of Keith Wilbur.

Sept 30/07