sonar question

[Joe S]

In SHIV enemy ships often approach undetected by the sonar man. I would like to think that a real sonarman would not let that happen. However, If the sonar man was tracking a particular contact, how likely is it that another ship, such as a destroyer, could make an attack run on the sub without being detected? I imagine it would be very possible, but dont really know so if anyone can answer that for me I would appreciate it. If such is the case, I will be a little bit less upset when it happens in the game. Is there a way to get the sonar man in SHIV to run periodic sweeps on his own or must be tell him to do so every time? Thanks! Joe S

[Webster]

its like focusing with your eyes, you can lock into one target but it doesnt block out your vision of everything else in the direction you are looking. however to get your attention it would need to do something to get your attention, in this case i would say it could easily get pretty cloce before it gets his attention but he should still catch it before its on top of you.


i would assume in real life it would maybe get half way closer then it normally would if he was zeroed in on another ship. but thats assuming the un noticed ship was in the same direction so it wouldnt be in a blind spot so to speak.

all this is just my opinion based on things i read about detection cone angles and how sounds are detected but even from the blind spot IMO the engines of a DD should be heard before its seen dropping cans on your head. :o

[GoldenRivet]

As far as im aware, WWII Era hydrophones were focal... meaning the operator could only hear whatever object he had the receiver head pointed at.

This would in fact mean that if you were focusing on the actions of a destroyer located on bearing 060, that the destroyer slowly approaching you from bearing 240 would be undetected.

A good sonar man will keep his hydrophone receiver moving between whatever nearby ships he would consider to be threats to the boat, and he would keep the commander continuously appraised of the situation as best he could.

However it is completely plausible that a sonar man, while focusing on the actions of one DD - might be completely unaware of the actions of another DD.

In addition to everything i just told you, you would be amazed at the clarity with which you could hear events underwater with the "naked ear" - Bulk heads collapsing from several thousand feet away... or even a couple of miles away. Engines thrashing about the sea etc.

It would be my assumption that the crew could audibly hear the engines of an approaching DD... perhaps not if it were creeping ahead at dead slow speed... however, when the DD sets flank speed to initiate an attack run, such sounds would probably be quite noticable aboard the U-Boat.

one final thing to consider... even though you might hear the sound of the DD accelerate to flank speed to initiate a depth charge run... he would literally be only seconds away from dropping his ash cans all over you, so you would have only a split second to react to the impending attack against you. Further consider that it would take the U-Boat some time to accelerate or maneuver under the coming threat.

This was a common tactic with destroyers against subs.

1. Split the u-boat's attention - the more destroyers you place around him, the more the U-boat must divide his attention in different directions. This reduces the subs overall situational awareness and makes it easier to attack.

2. Have one DD listen, while others ping away with active sonar... this way, while the sub tries to slip away, or accelerates to flank speed to escape attack, the lone DD can hear it and keep the others informed.

3. Creeping attacks. The DDs hydrophones become more and more useless as speed increases. so creeping the DD ahead at very slow revolutions would cut out as much background noise as possible... this would also make it very difficult for the U-boat to hear the approaching DD until it was too late.