Another Hollywood myth is about to be smashed….
We didn’t whisper, or talk in hushed voices, — we did wear sneakers but it was for comfort and we did put signs above the hatches reminding us not to slam the WT doors. We had an ever present awareness of noise but ambient noise was unlikely to get outside the hull- for example- during the Cold War, we took off all the lavatory doors before every mission and hung a drape.
Why? Not because closing a 3/4 inch thick door would make noise, but because sitting there every day looking at a drape instead of a door was an ever present reminder to think about being quiet. We used to leave the doors in the ship Storage container in port.
Sonar is designed to exploit the noises associated with machines and propulsion – be they rotating machines such as motors and pumps, or hydraulic machines such as torpedo doors, trash disposal, diving hydraulics, ordnance handling, etc etc.
I remember doing a sub-ex (sub to sub shooting range time for training) during the cold war, we’d do months of this type of training just to keep us sharp between deployments —typical ops — I track you, you track me, go to opposing corners and come out fighting, sometimes a surface ship would be involved. a lot of times we got to shoot exercise torpedoes. whatever…
On this one sub-ex, we got really close to the other ship (literally on top of her- we probably had more vertical separation than horizontal) and our CO sounded our collision alarm and our general alarm just to see what would happen (the two loudest alarms on the ship) and when we returned to port, I asked my friend who was a JO on the other boat if they heard anything … “Nope, never heard them!”
They were at battle stations, just like we were, with the second best operators in the fleet on every stack (sonar computer) and still they didn’t actually hear any of the alarms.
Ambient noises in the air space of a ship have little appreciable way for the sound to get transmitted through the hull and into the water…
edits for grammar and typos- thank you to those you suggested them – Darn spell checking doesn’t necessarily handle all words correctly.
