Historical method intercept by hidrophone

[3catcircus]

Originally Posted by Mariner1

Great tutorial - thanks for posting!

I could be wrong, but I can't see the 4 bearing method being used. IIRC, it is essentially bases upon determining a Spiess line - something that wasn't figured out analytically until later - Spiess's paper wasn't published until 1953.

An easier method is to directly use blade count to determine speed in combination with a bearing / bearing rate plot and fitting the range to the lines of bearing based upon how long the distance between them needs to be for the given speed. Accurate enough for ranges we want to be at for our attack. And when visibility sucks, you can race to an attack position on the surface before submerging again to pick the target up on the hydros.

Much easier than trying to guess a locus point for a future theoretical bearing.

[hauangua]

Originally Posted by derstosstrupp

From my understanding, the hydrophone technology in WWII didn't provide pinpoint accurate bearings. From reading the U-boat commander's handbook, the hydrophone is described really as an auxiliary tool for general awareness of your surroundings and not for targeting specifically (although it could provide hints about enemy speed through turn counts). Generally, it seems that doctrine called for getting to the surface as soon as possible because there the boat is the most maneuverable and can take advantage of the situation. The 3- and 4-bearing methods certainly work, and can be practical if you can figure out how to do them while moving, because sitting still and waiting the time periods necessary, especially submerged, just wasn't done. The German theory was to get into a position as quickly as possible to where the attack could be carried out, and then move to the target to launch the attack in the least amount of time.

Originally Posted by 3catcircus

I could be wrong, but I can't see the 4 bearing method being used. IIRC, it is essentially bases upon determining a Spiess line - something that wasn't figured out analytically until later - Spiess's paper wasn't published until 1953.

An easier method is to directly use blade count to determine speed in combination with a bearing / bearing rate plot and fitting the range to the lines of bearing based upon how long the distance between them needs to be for the given speed. Accurate enough for ranges we want to be at for our attack. And when visibility sucks, you can race to an attack position on the surface before submerging again to pick the target up on the hydros.

Much easier than trying to guess a locus point for a future theoretical bearing.

Thanks Very interesting your answers
That's what I think too
I do not think there was a formula or a particular method
Hydrophones were used to "have an idea" of the situation until the target was visible and only then did the hunt begin