Immersive techniques for the true subsimmer!

[Storm501]

Perhaps I didn't write my question specific enough

Why didn't Kriegsmarine U-boats submerge at night for the purpose of listening for merchant shipping on the hydrophone. Surely you can hydro-hear a darkened ship/convoy further at night than you can see it?

Yes, once a hydro contact is made and rough position/course established, U-boat would surface and race at full speed intercept course for the hydro contact.

Approach and attack surfaced of course (before escort radar). Only spotting at 5-25 km range pre-approach until visual contact with the aid of hydrophone.

[John Pancoast]

Originally Posted by Storm501

Perhaps I didn't write my question specific enough

Why didn't Kriegsmarine U-boats submerge at night for the purpose of listening for merchant shiping on the hydrophone. Surely you can hydro-hear a darkened ship/convoy further at night than you can see it?

Yes, once a hydro contact is made and perhaps rough position/course established, U-boat would surface and race at full speed intercept course for the hydro contact, and perhaps to listen again a bit closer to check that the intercept course is correct.

Probably for the same reason they didn't do it during the day; doing so is looking for a needle in a haystack, i.e.
That's what rdf, other boats sightings/beacons, BdU info. etc. was for.

[derstosstrupp]

The hydrophones were a very unreliable tool, an aid at best. That’s why the doctrine was to stay surfaced to search for contacts and only submerge and listen if compelled to do so. This doctrine is reflected in the commander’s handbook. I would recommend reading the book “Secret Diaries of a U-boat” by Hirschfeld, he was a radio man and that book lays bare the real shortcomings of hydrophones. They were dependent on the salinity of the water in sea areas, the plankton content, many factors affected their usability. His skipper, the ace Bleichrodt, had very little use for them as is evident in the book (apart from using them to evade, and even then he doesn’t trust it - his words: “what’d I tell you Hirschfeld, the tech is ****”)

No game gets hydrophones right. They are highly overpowered in every sim I’ve ever seen.

[John Pancoast]

Originally Posted by derstosstrupp

The hydrophones were a very unreliable tool, an aid at best. That’s why the doctrine was to stay surfaced to search for contacts and only submerge and listen if compelled to do so. This doctrine is reflected in the commander’s handbook. I would recommend reading the book “Secret Diaries of a U-boat” by Hirschfeld, he was a radio man and that book lays bare the real shortcomings of hydrophones. They were dependent on the salinity of the water in sea areas, the plankton content, many factors affected their usability. His skipper, the ace Bleichrodt, had very little use for them as is evident in the book (apart from using them to evade, and even then he doesn’t trust it - his words: “what’d I tell you Hirschfeld, the tech is ****”)

No game gets hydrophones right. They are highly overpowered in every sim I’ve ever seen.

Though it could be argued that having them overpowered helps with the situational awareness shortcomings that 2d pc limitations can sometimes cause.

[Storm501]

I took a look at Uboat.net

Possibilities of underwater sound detecting in WW2:

Experienced underwater sound detector operator was able to determine is a detected ship a cargo ship or a warship (type of the warship), approximate speed or manoeuvre of the ship (approaching, digression, increasing or decreasing of speed and depth, if detected object was a submarine).

When detected (submerged) submarine stopped her moving, the operator was able to determine which mechanisms of the submarine still operated. To avoid own noises, a submarine could use underwater sound detector if her speed was up to 6 knots. If a submarine speed was 4 knots, the submarine's underwater sound detector average distance of detecting another object was:

- for a destroyer- 5 to 10 nautical miles, (9-18km)
- for a cargo ship- 3.5 to 7.5 nautical miles, (6-14km)
- for a convoy- up to 50 nautical miles. (90km)

If a submarine speed was 15 knots, the submarine's underwater sound detector possibility of detecting another object was rapidly decreased [although no submarines except XXI and XXIII were able to reach that speed during WWII]. In that case, average distance of detecting another object was up to few hundred metres.

Ok perhaps in game hydrophone is bit overpowered if it always hears Merchant at 25 km. On the other hand, these are average ranges at 4 kn speed, so at 0 kn or optimal conditions ranges could be up to 25 km.

So it is hard to tell a final conclusion. Seems that we are left with the first hand accounts of the people using the hydrophone. Also I have to believe that if using hydrophone at night would have granted a significant advantage, surely the U-boat crews would have seized it. Hundreds of crews had spent thousands of hours at sea, so I imagine they tried everything to increase tonnage sunk.

[John Pancoast]

Originally Posted by Storm501

I took a look at Uboat.net

Ok perhaps in game hydrophone is bit overpowered if it always hears Merchant at 25 km. On the other hand, these are average ranges at 4 kn speed, so at 0 kn or optimal conditions ranges could be up to 25 km.

So it is hard to tell a final conclusion. Seems that we are left with the first hand accounts of the people using the hydrophone. Also I have to believe that if using hydrophone at night would have granted a significant advantage, surely the U-boat crews would have seized it. Hundreds of crews had spent thousands of hours at sea, so I imagine they tried everything to increase tonnage sunk.

Myself, I'll take first hand accounts of info. over most anything else including uboat.net. I.e., WW2 subs could not stop and hold in place.
To often specs. of equipment/weapons used in games are "laboratory" specs. vs. specs of use "in the field". The two rarely are the same.

[NiceSub]

Originally Posted by derstosstrupp

The hydrophones were a very unreliable tool, an aid at best. That’s why the doctrine was to stay surfaced to search for contacts and only submerge and listen if compelled to do so. This doctrine is reflected in the commander’s handbook. I would recommend reading the book “Secret Diaries of a U-boat” by Hirschfeld, he was a radio man and that book lays bare the real shortcomings of hydrophones. They were dependent on the salinity of the water in sea areas, the plankton content, many factors affected their usability. His skipper, the ace Bleichrodt, had very little use for them as is evident in the book (apart from using them to evade, and even then he doesn’t trust it - his words: “what’d I tell you Hirschfeld, the tech is ****”)

No game gets hydrophones right. They are highly overpowered in every sim I’ve ever seen.

So what kind of search pattern on the surface we should set up to find targets? How should I sail it? Also SH5 has that thing where if you are using TC the game will stutter for a second when its loading target in your area. For me that is a sign to dive and listen on hydrophone, in 99% cases I will hear something.

[derstosstrupp]

Originally Posted by NiceSub

So what kind of search pattern on the surface we should set up to find targets? How should I sail it? Also SH5 has that thing where if you are using TC the game will stutter for a second when its loading target in your area. For me that is a sign to dive and listen on hydrophone, in 99% cases I will hear something.

Typically they traveled up and down in their area. That’s what I do as well. I’m also ok with going weeks without a sighting as was historically often the case.

What I wish we had is Vorpostenstreifen, the patrol lines set up by BdU north to south. He would even tell boats “travel x degrees at x knots til further notice”.

We are way more on our own in these sims than they were in real life. BdU dictated their every move in most cases. It would be nice to get more orders like that.

[bstanko6]

I started a discord server called War Room. It's a war game channel, but I also have a channel for SH5. Come on over and join me and others for games and chat!

Discord:
https://discord.gg/6tFeTSUmVc

[derstosstrupp]

Joined (Stosstrupp)!

[bstanko6]

Thank you friend!

[les green01]

joined Les Green,does anyone else like to watch them load the eels in the tubes

[bstanko6]

Uh yeah! It’s like waiting for Christmas!

[Noonai]

Back from a long break on SH5 for lack of time and work reasons but coming back again! And I see this thread it's still going very strong so hopefully I will be able to contribute. But happy to see I have 6 or 7 pages to read through.

[les green01]

ok question for the experts 09-01-39 at 0130 you sight a british u class do you pop it or send a contact report