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

[Jmack]

OK ... here is the result of the interrogation to the Engineer Officer of U-615.
this would be a really nice MOD to have if anyone could do it


In June 1943, a new instrument known as the "Wabe-Ortungs Gerät" (literally, "Depth Charge Locating Gear") was installed on the port side of the control room, just forward of the periscope motor and above the potato box. The visual part of the instrument was described as a bakelite panel about 30 cm. by 50 cm., attached directly to the pressure hull by metal brackets. On the panel was the outline of a U-boat surfacing at a sharp angle. Forward and aft of this U-boat were cruciform arrangements of small colored light bulbs, and amidships was a horizontal line of bulbs. It was stated that five bulbs were in each arm of the cross, and ten were in the horizontal line. The bulbs were spaced about 20 mm. apart. The bulbs to the left were red, to the right - green, above -- white, and below -- blue.

During an attack, lights flashing on the panel indicate the approximate position of the explosion of depth charges. The red lights indicate explosions to port, green -- to starboard, white -- above, and blue -- below.

It was stated that the instrument had a range of 500 meters. One prisoner was under the impression that when an explosion was located, it would be the policy of the captain to take the boat to the general area of the explosion, both on the theory that lightening never strikes twice in the same place, and as evasive action against echo-ranging.

Beneath the panel was a storage battery, placed on top of the potato box. The panel was covered at all times by a canvas cover except during an attack. The device was regarded as extremely secret and only could be served by the captain or the engineer officer.

When questioned about the Depth Charge Plotter, the proved to be evasive, tricky, unreliable, and an unblushing liar. At first he denied the existence of such a device. When confronted by evidence to the contrary in his own note book, he stated that the instrument never functioned properly and that he regarded it as being only in its infancy. He said that the day after U-615 sailed, he discovered that several of the lights failed to function properly due to short circuits or faulty wiring. He felt that the sweating of the pressure hull might have caused some damage to the device. These statements are substantiated by an entry in his notebook which, in translation, reads as follows:

Depth Charge Plotter:

Shut off due to short circuit forward 13 June

Aft, below 1, 2, 5.
Aft, above 2.
Amidships port 5. forward (?) short circuit
Forward above 3.

(O.N.I. Note: The numbers probably refer to the various bulbs which were removed.)

On 14 June 1943, U-615 was attacked by an aircraft and the Depth Charge Plotter was tried out. The Engineer Officer kept a partial record of the lights which flashed. In translation it reads as follows:

Bombs at 55 meters (stated to refer to the depth of the U-boat)

Port forward 1; Port amidships 1; Port aft 1 and 2.

The last entry reads:

Three Depth Charges

Aft port 2.
Aft starboard 2.
Below starboard 2.
Forward port 1.

[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

Good points from the Historical, tactical, and pratical point of view.
As far as Modding it.:hmm:
Main thing I'm look for is a way AROUND all the zon, cfg, etc stuff.
Reason being is all that is data input!
The more data to input, the slower we run.
This game is Dynamic in the way it access data! (IMHO)
Now, IF we can mod the act files (which handle ALL the data)
or mod the dll files?
THEN everything would run FASTER, STRONGER, BETTER!
Perhaps the Pescarus routine could be modded to be used
for this being as they only show up near land?

[sublynx]

Interesting report. I'm necroing this because I've never heard anything about this kind of stuff. Does anybody know anything about "Wabe-Ortungs Gerät"?

[BigWalleye]

Originally Posted by sublynx

Interesting report. I'm necroing this because I've never heard anything about this kind of stuff. Does anybody know anything about "Wabe-Ortungs Gerät"?

Jmack included just about everything I could find on the web about the German device in his first post above. The USN did have a cover version, also mentioned above. The only additional information I could turn up was a reference to Fluckey's book "Thunder Below". He talks about using the USN device in a couple of combat situations. He seemed to find it useful. AFAIK, that is the only first-person account of the device in operational use.

[brett25]

from that last entry it looks like he was bracketed...the British were dead on

[sublynx]

Probably the thing was a prototype of sorts. Possibly only carried in a few boats and then abandoned as nothing is known about it.