Using SH5 to visualize Uboat attack tactic ?

[McBeck]

As some of you know, I have a small Youtube channel where I create videos. Normally I would focus on walkthrough videos, but as I cant travel atm, I focus on videos I can create without travel.

I have just premiered a video on the German type XXI design, but I am already inspired to do the next project on the battle of the Atlantic.

In this video I would like to show how a uboat would line up an attack, and how the convoys were protected by destroyers. Do you think a picture of the uboat laying submerged ahead of the convoy, would be a historically correct representation of the tactic used?

I have also ordered the books "Hitlers Uboat" war and hope this would also add more factual foundation for points I could raise in a video...

[Catfish]

Of course SH5 could be used, though i am more familiar with SH3 +GWX.

Lying (almost) still ahead of a convoy is a good idea, if you a) do not show your periscope and b) one of the leading escorts does not accidentally run over you.. risky business. Keep your bow in direction of the convoy's course for less exposition, from accidentally surfacing to ASDIC echo profile just in case, to engine noise.
Also this tactic depends on letting embed you in the upcoming convoy columns, then turn 90 degrees and calculate torpedo solutions. You do not need 90 percent angle, and the TDC is well able to calculate the shots beforehand, but 90 degrees and close is usually the best situation for any submarine attack.
Also when the convoy zig-zags with you ahead of it, you will have to do it all again.. unless you are very lucky.

In the convoy submerged, you would have to be very quick, since once near/in the convoy with the escorts past you, you HAVE to use the periscope. No problem at night and in any but calm seas, but you have to have good situational awareness of those hulks steaming all around you.

Ahead of a convoy it is of not much use to lie at a greater depth than PD though, because ASDIC will most probably detect you from 30 meters on, also you need time to get up at PD and find your targets.

The classic tactics in early war was to just go in from behind at night surfaced, evading the escorts, and patiently pick your targets, maybe even attack with the deck gun. You can outrun any corvette surfaced, and you will usually know the convoy's general course from watching some time before. Wait for a zig or a zag until the cloumns have gone into formation again, then strike.
ASDIC is pretty useless against surfaced boats and most escorts did not have radar in the early war, the merchants will also shield you from visual or radar detection, no hydrophone will hear you among the merchants' screws, and no one will see you below the horizon at 5-7 knots from the ships's side, running in mid of the rows with the merchants.

Or the real classic tactic is outrunning the convoy with the "Hundekurve" just out of detection range (visual or radar), +- parallel to the general course, count the escorts, mark their general positions, and then break through the escort screen with no moon or the moon ahead at full speed. You then have the convoy's speed from observation and can hit 3-4 pre-picked ships in one run. If they do not detect you (mind you you can see them but not vice versa), you can run with the convoy and reload the tubes.

Otherwise (detected) you make a crash dive and try to survive the following depth charges - as long as you are under the convoy no ASDIC or sound gear will detect or hear you, but once the convoy is ahead .. After diving (being detected or not) you will be out of the game for a while, and have to outrun the convoy again when situation allows.


Good luck

[derstosstrupp]

Have to second pretty much everything Catfish has said. Generally, doctrine was to always be moving toward the target vs lying in wait, so often times they would approach even at five or six knots when running in from the front submerged, slowing down to take periscope peeks, then slowing to approach speed within 4-5000 m. The commander’s handbook stressed the shot needs to fall at the earliest possible moment.

I would show a U-boat on a parallel but opposite course, at periscope depth, perhaps 1500 m off the target track.

[McBeck]

Okay, so after May 1943, I guess the tactic shifted more to lying ahead in wait - would you agree?

I guess I need to review the handbook, but I have references stating that at some point the type VII and IX only got one shot because they couldn't catch up with the convoys after that.

[derstosstrupp]

I would say from that time on, many attacks were happening from outside of the perimeter of the convoy. Diving directly in front and approaching and entering the convoy from the front became a less viable tactic at that point.

[Jimbuna]

Originally Posted by Catfish

Of course SH5 could be used, though i am more familiar with SH3 +GWX.

Lying (almost) still ahead of a convoy is a good idea, if you a) do not show your periscope and b) one of the leading escorts does not accidentally run over you.. risky business. Keep your bow in direction of the convoy's course for less exposition, from accidentally surfacing to ASDIC echo profile just in case, to engine noise.
Also this tactic depends on letting embed you in the upcoming convoy columns, then turn 90 degrees and calculate torpedo solutions. You do not need 90 percent angle, and the TDC is well able to calculate the shots beforehand, but 90 degrees and close is usually the best situation for any submarine attack.
Also when the convoy zig-zags with you ahead of it, you will have to do it all again.. unless you are very lucky.

In the convoy submerged, you would have to be very quick, since once near/in the convoy with the escorts past you, you HAVE to use the periscope. No problem at night and in any but calm seas, but you have to have good situational awareness of those hulks steaming all around you.

Ahead of a convoy it is of not much use to lie at a greater depth than PD though, because ASDIC will most probably detect you from 30 meters on, also you need time to get up at PD and find your targets.

The classic tactics in early war was to just go in from behind at night surfaced, evading the escorts, and patiently pick your targets, maybe even attack with the deck gun. You can outrun any corvette surfaced, and you will usually know the convoy's general course from watching some time before. Wait for a zig or a zag until the cloumns have gone into formation again, then strike.
ASDIC is pretty useless against surfaced boats and most escorts did not have radar in the early war, the merchants will also shield you from visual or radar detection, no hydrophone will hear you among the merchants' screws, and no one will see you below the horizon at 5-7 knots from the ships's side, running in mid of the rows with the merchants.

Or the real classic tactic is outrunning the convoy with the "Hundekurve" just out of detection range (visual or radar), +- parallel to the general course, count the escorts, mark their general positions, and then break through the escort screen with no moon or the moon ahead at full speed. You then have the convoy's speed from observation and can hit 3-4 pre-picked ships in one run. If they do not detect you (mind you you can see them but not vice versa), you can run with the convoy and reload the tubes.

Otherwise (detected) you make a crash dive and try to survive the following depth charges - as long as you are under the convoy no ASDIC or sound gear will detect or hear you, but once the convoy is ahead .. After diving (being detected or not) you will be out of the game for a while, and have to outrun the convoy again when situation allows.


Good luck

Credit where credit is due....that pretty much sums it all up Kai

[Catfish]

^ Oh thanks, i just read this


Maybe someone has other tactics? I feel i get sunk much too often with mine ..

[McBeck]

So the historic tactic was to approach the convoy from the rear and infiltrate?

[Catfish]

In the early war, yes. But it needed a certain nerve to do it, so not all U-boat commanders did.
They also went in from the side, fired, and then ran with the convoy while reloading. In case of a corvette they would run around merchants and finally outrun it. With the later real destroyers or the DDE destroyer escorts it became difficult though.
At night no one would see the sub and ASDIC was useless against surfaced boats. No radar in the early war, very few escorts, sometimes none, or only corvettes that could be outrun at the surface with the faster U-boats.
Once in the convoy the lookouts spotted merchants and escorts earlier than vice versa, the boats could glide into the shadow of a merchant and out of it, it is reported that corvettes came very close or crossed the immediate backwash without spotting the boat.

With more escorts, and fast destroyers used as escorts, this tactic became obsolete. During opeartion drumbeat it was again possible for a short time, but this was never war-decisive.

After all it was more and fsater escorts, radar, but as a number one threat the aircraft, that made attacks more and more difficult.

I have not read Clay Blair's books, but almost anything else - not sure whether there is much more information in his book? Whatever it was not quite as easy to kill the U-boats as it is portrayed in the propaganda films of the time, or our time.

[Jimbuna]

Originally Posted by Catfish

I have not read Clay Blair's books, but almost anything else - not sure whether there is much more information in his book? Whatever it was not quite as easy to kill the U-boats as it is portrayed in the propaganda films of the time, or our time.

You really should Kai, they (both volumes, Hunters and Hunted) are the most informative on said subject matter imho.

[Catfish]

I just found them on booklooker.. i guess there goes my spare money for the month.. "thanks"

[Jimbuna]

I will also highly recommend another of his books Silent Victory if you have any interest in the US submarine war against Japan.