Of what era are we talking of? I served during the Cold War (76-79) and at the time all we were concerned with was russian Alpha and Whiskey clas subs. When I went to Sonar "A" school in April of '76, we just recieved news that they were building the "Typhoon" class sub. Of course they were building the "Kiev" and Moskva" class ships, half battleship, half aircraft carrier. I was serving on board the USS Aylwin (FF-1081) and we had an AN-SQS 26CX sonar with a MK 114 Fire control system for the ASROC system which was later outfitted to fire Harpoons too. We also had an AN-SQS 35 VDS (variable depth sonar). Below the main deck at the fantail was a large room that held a crane and the sonar. You had to read your charts VERY carefully because Ensign Hymen didn't and he slammed it into an undersea mountain! After the captain gave him 10 new rectums later, dropped him 1 in rank and pay, the gov'ment paid 15 million doleros for a new fish. We're talking approx. 6 feet in length by 4 feet high. We never used it very much because of the accident I just told you. The CX sonar had Omni- directional, convergence zone, triple frequency and two more I can't remember. We usually had it passive, that way you could hear a russian sub run their garbage disposal, open/close their torpedo doors and listen to their awfully noisy enginesfrom a max of 150 miles away. We used to sneak up on them when they were cruising at periscope depth and hit them with a 7 second pulse from our sonar! They would surface and we would cruise around them in circles taking pictures for the CIA and the Navy.
