Passive Torpedo Problems

[Soundman]

I'm hoping someone can help me here. I have launched many passive MK-48s in passive mode and not one will hit a target. So I tried an experiment with truth turned on and wire guided the thing directly to the target and nothing. And yes, the fish were enabled. I have even guided the torpedo and watched a torpedo go directly through a submarine. I first thought maybe a problem with a patch or a bad install perhaps. Re-installed and the same thing happens. Hmmm?.....O.K......Re-installed with no patches.....same thing. I even went as far as thinking it was an "XP PRo" thing..Nope, I tried it on my old computer....Same thing.....Oddly enough, I even re-installed Sub Command and even it does it too...I must be overlooking something terribly simple here. My active fish hit nearly every time. I use the same procedures with actives as passives except I uncheck the box. (to select passive mode). Any Suggestions? Thanks!

[JamesT73J]

Speed. I can't remember what the threshold is (never use the things), but you can't run them at full speed -they won't hear anything.

[Soundman]

I'll give that a try. Thanks for posting!

[Molon Labe]

45 knots is usually low enough in the stock game, although there might still be partial washout at that speed.

[Soundman]

Ah, Success! Yep, you guys were right on. I set the fish at 40kts and KABOOM. Thanks much! I figured it must be something simple. Never had to do that with Janes 688I.

Soundman

[SeaQueen]

Sort of a related question...

Has anyone noticed if torpedoes are more quiet when you shoot them at less than full speed?

[Fish]

Originally Posted by SeaQueen

Sort of a related question...

Has anyone noticed if torpedoes are more quiet when you shoot them at less than full speed?

I launched a torp at 35 and a litle later one at 55, when they are equal at range I saw no different .
I used the LWAMI mod.

[LuftWolf]

In the stock game, there is no difference in sound vs. speed other than cavitation (+10PSL or about 15dB).

In LWAMI torpedoes have an addtional +10PSL when traveling at full speed, scaled linearly down to +0 at 0 kts, as well as the +10PSL when cavitating.

Cheers,
David

[Phullbrick]

any idea of the best speed to use for a passive torpedo to reduce the washout effect on the torpedo sensor ?

[Amizaur]

In game currently - under 46kts. But I don't like this value and it should be lowered. Realistically - 40kts or below for passives.

[Phullbrick]

dziekuje Amizaur

I'll try to get some info from "real world" if possible

[Fish]

Originally Posted by LuftWolf

In the stock game, there is no difference in sound vs. speed other than cavitation (+10PSL or about 15dB).

In LWAMI torpedoes have an addtional +10PSL when traveling at full speed, scaled linearly down to +0 at 0 kts, as well as the +10PSL when cavitating.

Cheers,
David

LW, I wonder it should be liniar? Just a feeling but shouldn't the noise not rapidly increase at higher speed?

[Qppralke]

BTW. I remember you could launch torpedo , deep enough to not cause "Torpedo in the Water" on other players boat. Anyone remember how deep it has to be ?

[goldorak]

Originally Posted by Tusipex

BTW. I remember you could launch torpedo , deep enough to not cause "Torpedo in the Water" on other players boat. Anyone remember how deep it has to be ?

I think that only applies to the uuv. :hmm:

[LuftWolf]

Originally Posted by Fish

LW, I wonder it should be liniar? Just a feeling but shouldn't the noise not rapidly increase at higher speed?

Well, that's the way it has to be done because of the way the engine works. We have taken care to calculate the base PSL values accordingly.

It's really not THAT big a deal, because the cavitation profiles for the torpedoes are good enough that slow torpedoes make much less noise than fast torpedoes because they don't cavitate except if at very shallow depths.

So, for all practical purposes, in terms of in game performance, it is exactly as you describe, Fish.

Cheers,
David