"Wabe-Ortungs Gerät" (literally, "Depth Charge Locating Gear")

[Sailor Steve]

A submerged u-boat is big, clunky and slow. Once the depth charges were in the water I think it became a matter of luck as to how close they were, and all were going off pretty much at the same time. Then the destroyer would make another attack. The time for evading is just before they drop. It seems to me it's like a bomber trying to evade flak; by the time you know where it is it's already too late.

That they had such a device (or may have) is interesting. That it didn't work too well doesn't surprise me.

[Jmack]

well .... i believe that the working method was not to detect the DC's falling in the water , but it was to locate the explosions by the shockwaves since the device was atached directly to the pressure hull and to make the u-boat go to that area since it has been ALLREADY sweeped by the enemy it would give at least a couple more minutes to decide what to do .


THIS ASSUMING THAT THE FIRST ATTACK MISSED THE TARGET

[Jmack]

the U.S. submarines also used this kind of equipment probably
developed after capturing german crews and u-boats using the
german model as reference


the U.S. version is DCDI ( depth charge direction indicator )




and the DCRE ( depth charge range estimator )




Catalogue of Naval Electronic Equipment-April 1946

[Sailor Steve]

Originally Posted by Jmack

well .... i believe that the working method was not to detect the DC's falling in the water , but it was to locate the explosions by the shockwaves since the device was atached directly to the pressure hull and to make the u-boat go to that area since it has been ALLREADY sweeped by the enemy it would give at least a couple more minutes to decide what to do .


THIS ASSUMING THAT THE FIRST ATTACK MISSED THE TARGET

I understood what you meant. In the First World War a British destroyer captain being shot at by a larger ship started "chasing splashes", as he called it. If a salvo landed two hundred yards long he would head that way, assuming that the firing ship would correct down ladder, and when the next salvo hit where he had been he would now be where the first salvo landed, making the new salvo fall short.

Unfortunately, destroyers don't drop depth charges that way. There is no "we bombed point X, now let's go try point Y", so there is no point in the sub heading for point X. The destroyer drops a pattern where his sonar tells him the sub should be. Once the depth charges explode the water is highly disturbed and he loses contact. He slows down and circles, searching the area hoping to regain contact. If he does, he then once more heads for the sub and tries again.

If he was off by several hundred yards, the sub captain is going to hear faint explosions in the distance. Knowing that the attacking destroyer is way off base, he's not going to go where the attack is; he's going to try to sneak away in the opposite direction.

[peterloo]

That stuff is interesting but not practical.

Although you can know the explosion direction, a few destroyer can still kill you, and there's no way for you to escape since you are locked

Just like modern torpedoes (e.g. Mk.48) Once it lock its target, the fish will chase after you. The only way to reduce damage is the use of decoy