Selecting appropriate underwater speed when near or under a convoy

[Paul Riley]

I have had this thought for a while now,and it has me curious.Say if I wanted to maintain close contact with a convoy,by being very close to it naturally,or even under it,would the convoy detect me if my engine speed was set at their speed?.I imagine the convoy would hear me among their own noise if my engines were running higher than theirs.They would detect a sound anomaly?.

As 1942 is closing to an end in my campaign and their underwater listening capability has increased since my last patrol being too close to a convoy would seem suicidal,yet...it would give you a tactical advantage as under it you are already within the screen,and so an attack could be made easier and more frequently,instead of having to evade,set up new attack run,intercept,then engage.Theoretically it could allow attacks on the convoy every 2 hours or so,or when they have finished their zig zagging after an attack,and return to course.

Cheers for any info on this matter :up::salute:

[Contact]

When underwater you are useing batteries. The sound of electical engines is far more different than diesels. So you could go under the ship, the escorts and experienced its crew could still detect your noise.

[Paul Riley]

Ahh I see.Stupid of me not to take into account electrics would sound different to diesels :88)
I guess either way it is a very risky enterprise staying too close to convoys 1942+
Well,thanks for that.

[Otto Heinzmeir]

I think if your props are quiet enough and you are almost directly under a merchant, the merchant's engines would mask your prop noise. It probably depends on the speed of convoy. If they are doing 5 knots, your probably ok. If there doing 8 knots then probably not. Even if they didn't here you doing 8 knots, that speed will drain your batteries quickly.

[HW3]

Also an experienced sound man can tell what he is listening to by the sound of the props revolutions. Slow revolutions are merchants, high speed are warships, ect. So even if the sound of your engines didn't give you away, the distintive sound your props make would.

[Sag75]

I have just a technical question about this..

Is really modelled in SH3 the masking of your engine noise by merchant engine? :06:

[Contact]

I have just a technical question about this..

Is really modelled in SH3 the masking of your engine noise by merchant engine? :06:

No.

[HW3]

As Contact said it is not modeled. There have been reports of skippers trying to hide from escorts under a merchant. The escorts just circled the merchant dropping depth charges, and refused to leave even after they ran out of them. I have tried running through convoys submerged in silent running at 2Kts, and the escorts followed me right through pinging away. If they get close enough to ping you, you won't lose them just running under a convoy.:yep:

[Contact]

It's quite a nice trick to "play" game "catch if you can" with escorts while shielding yourself under the ship :haha:

Escorts shouldn't have thrown DC around a merchant since I believe there would be no effect and even might be dangerous for merchant itself. All escorts had to do is listen/ping and follow. As soon as batteries runs out U-boat looses it's cover and then.. :timeout:

The fun depends on how smart AI is of course :)

[Paul Riley]

In a nutshelll then I think we can all agree that the best strategy is just stick to trying to slip through and make as much distance between yourself and the convoy as you can.I normally evade on a 90 degree course from the convoy's previous course,evade DCs for approx 1 hr using whatever methods I can at that moment,slowly come to PD with no ballast,have a quick scan around,then surface if all is clear.Or,I would just wait until I am in my predetermined radar clearance zone,and begin my next 'catch up' phase of the attack.I will never be bullied from a convoy into breaking off my attack,i'll keep at em until I run out of torps or have sustained significant damage,or am being harrassed too frequently by aircraft at the same time.

I just thought how thrilling it would actually be to follow under the convoy,then surprise them with your next attack from within :arrgh!:

Cheers for the answers anyhow.

[RoaldLarsen]

Well, I'm not so sure I agree. Once, in 1943, after I had attacked a slow convoy (5 knots?) and hit at least one ship, I tucked myself under a troop ship while I reloaded my four front tubes. Took at least 1/2 hour. Escorts did not detect me. I then slowed down, let the troopship get about 300m in front of me, fired a mag torp, which brought it to a halt. Waited for its friends to leave, and finished it off.

I'm not certain that the game models sound masking of sub by merchants, but on more than one occiasion it has seemed to do so.