Torpedo as decoy to passive homing torps?

[speed150mph]

So out of curiosity, in game and In reality, if an enemy submarine fired a torpedo at my sub in passive homing mode, if I fired off a fish at say 20 knots at 90 degrees of ownship course, and when silent, would the passive torpedo hear my torpedo and track it? Also if my torpedo was remote detonated, would the blast impact the torpedos ability to track? If so how would this work against advanced torpedos like the ADcap or mk 48 that have decoy recognition?

Anybody have any theory's or experience here

[Beardmoresam]

Not got any experience but I reckon that depends on if the torpedo takes interest in the noise a torpedo makes and if the attacking torpedo is enabled when the defending torpedo is within its detection range/arcs.

It would be very expensive to use a torpedo as a decoy both in money and in expenditure of an asset so I doubt it's usefulness given that subs generally carry decoys

[speed150mph]

Well unless your in a seawolf class that has multiple external decoy launchers, your decoy only has one shot at saving you, two if you can reload the launcher quick or have two passive decoys in the launchers. And I'd rather waste the money and firepower of a torpedo if it saves my multi-million dollar nuclear attack submarine. Any other theory's?

[OptimusX]

It is highly unlikely a passive torpedo would ever be used to track a submarine effectively. Keep in mind that your own passive sonar is only able to indicate direction, not depth.

[Hinrich Schwab]

I doubt a torpedo creates enough wake to attract a passive torpedo. It is like trying to stop a bullet by firing another bullet at the same in the hopes of cancelling each other out. Good evasion and countermeasure tactics can take the place of such an impractical solution such as a counter-torpedo.

[speed150mph]

OptimusX
I don't know about real life but I know in the game I can very effectively use a passive torpedo, being that a subs first action when the fish start swimming is to go to flank... I've also been sunk by them a number of times because they don't give off pings to tell you their enabled and locked on you. The only way to evade them effectively is to either run for your life and hope it runs out of fuel first, or drop a decoy, sprint as far as you can before you think it will enable and go all stop and go quiet. If it's close enough and your in a nuke, it will hear you anyway.

And Henrich
I didn't think that passive torpedos worked off wake, I thought they tracked by sound like a passive sonar. If that was the case, I thought that they would have no problem picking up the screw sounds and cavitation noise that a torpedo usually makes, they are not quiet at all. And for the record, I'm not really trying to take out the torpedo with my torpedo, I'm just trying to get the enemy fish to pick up the noise of my fish, and maybe try to follow it instead of coming after my quiet sub. But if passive torpedos do work off of wakes, then I could see how that would be a problem

[Hinrich Schwab]

And Henrich
I didn't think that passive torpedoes worked off wake...
Yes, that is how they work. Their sonar packages in torpedoes look for cavitation and disturbances caused by turning screws. For surface ships, cavitation is a given and is usually quite strong, hence why passive homers work for ASUW. However, they are not great for subs because of the anti-cavitation designs, speed discipline and other factors. We easily see this in both the narroband and broadband sonar displays and the challenges of positive classification because of the aforementioned factors. The only time a passive homer is good against a sub is as a nasty follow-up to an active torpedo. When a sub turns and burns away from an active torpedo, the sub is going fast enough and most likely is cavitating enough to give the passive torpedo a good enough signal to acquire. That is also why veteran skipper drop both an active and a passive decoy to avoid the possibility of a passive torpedo following the active one.

[speed150mph]

Well you learn something new everyday. And I know exactly what you mean, I've done that before.