AHC: Best possible German performance in the Battle of the Atlantic

In 1929 Rudolf Kuhnhold of the German Navy Signals Research Division began work on an air 'echo sounder' and in 1933 was suggesting research on centimetric waves to detect aircraft and ships. He was using Phillips magnetrons and Yagi directional antenna with a 13cm wavelength. The experiments were promising so he went to Telefunken in 1934. He spoke to mid-level manager Wilhelm Runge who was working on decimeter wavelengths. Knowing no one at Telefunken was working on centimetric waves Runge told Kuhnhold that he had neither the funds nor staff to spare to collaborate with the Navy. Kuhnhold took this as a rejection by the whole company and so left the navy and went off to form GEMA, a company to continue radar work for the navy. This took some years to set up and produced the early Seetakt radars but an early opportunity to collaborate on powerful radar systems was missed by a misunderstanding.

Lots of people were playing with centrimetric magnetrons in the 30's.
The problem is, they were all very low power - I believe the USN one, in 1940, could make about 500 watts
 

perfectgeneral

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Er, no. Just no....

Just for a start, pumping masses or air up through an opening your trying to close, through the control room, isn't the best idea...
Not what I said.
Imagine a funnel with a lid behind the conning tower making it more teardrop shaped. The last point to sink. So less time when water is resisting the outlet of compressed air. Gone in 25 seconds.
 
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Deleted member 1487

In 1929 Rudolf Kuhnhold of the German Navy Signals Research Division began work on an air 'echo sounder' and in 1933 was suggesting research on centimetric waves to detect aircraft and ships. He was using Phillips magnetrons and Yagi directional antenna with a 13cm wavelength. The experiments were promising so he went to Telefunken in 1934. He spoke to mid-level manager Wilhelm Runge who was working on decimeter wavelengths. Knowing no one at Telefunken was working on centimetric waves Runge told Kuhnhold that he had neither the funds nor staff to spare to collaborate with the Navy. Kuhnhold took this as a rejection by the whole company and so left the navy and went off to form GEMA, a company to continue radar work for the navy. This took some years to set up and produced the early Seetakt radars but an early opportunity to collaborate on powerful radar systems was missed by a misunderstanding.
Well there was also the 1905 device by Huelsmeyer:
https://en.wikipedia.org/wiki/History_of_radar#Christian_Hülsmeyer

Have the navy develop it pre-WW1...
 
Rossler reports that all the efforts to build up the sail cost [ especially the "Winter Garden"] them 1-2 knots and made the U-Boats more difficult to control underwater. The underwater turbulence made it particularly difficult to hold station at or near periscope depth. The key point is a transition from 'Unterseeboot' to true a 'submarine' that spends its time entirely underwater during the attack phase plus the approach -and where needed , the transit through troubled waters.

To get the crash dives- flooding slits cut the submerging time from a couple of minutes to 45 seconds. While this transition to true submarine reversed that process some what [not all flooding slits were covered] - the basic redesigns were already cutting crash dive times in half anyway. So crash dives took a minute...30 seconds with enough flooding slits.
 

CalBear

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Well, that's your first lie. Go read the thread title again.

You'll find the word 'possible'.

If you want to make a wank-fest, then I'll start feeding the Alien Space Bats, as their assistance will certainly help.

PS There is a hint in your sentence what could have made life more difficult for the Allies.
Don't do this.
 

hipper

Banned
I realise that any answer to the challenge must be realistic and that your scepticism is probably founded on this, but I feel you are starting to argue against the thread rather than the realism of the posts. The challenge is for the "best possible", not the winning performance of the KM in the BotA. Having said that you could argue that the best possible is none. Although you would have to do that, rather than just shoot down other posters.

Germany had gone to war in September 1939 with 57 U-boats, but only 26 of them were long-distance ocean going boats. That OTL circumstance will not successfully blockade the British Isles or reduce merchant tonnage to the point that blockade is moot. The test here, I feel, is to get closer to that point. More U-boats both for training and ocean going blockade bring up that tonnage, if they can engage successfully. "Happy Time"s reflect periods of the U-boat war where the KM were engaging with some degree of success. So an increase in U-boats available, of the correct sort, at those times, might be thought of as increasing performance.

Had Germany gone to war with 200+ ocean going boats, with the manufacturing that implies, and the training fleet and air forces to support a campaign on that scale, it is far more likely that they would have been successful. Although in WW1 far more ships were hit without capitulation, so look for a huge early improvement before a tipping point is reached.

uboats-ships-hit.gif


Many of the counter-measures wouldn't have time to enact before a tipping point in the fighting capability of the British Isles would be reached. Anticipating some of these counter measures only puts back the deadline for reaching that tipping point. It seems to me that 1939-1941 with sustained losses of over 5,000 ships per year might do it. How many U-boats would that require, given counter-measures in place during the early war and proportional response to losses?

Any measures later than March 1941 start to fall foul of the counter-measures improving to a deadly degree.By 1945 the Allies are running out of targets.

uboats-losses.gif
The Defensive measure is the early adoption of Convoy, which kept losses under 500 per year the way for Germans to be more succesfull in the Atlantic battle is for the UK to delay the introduction of convoy.
 
my view Axis HAD two weapons in 1940 that if better utilized would have changed the calculus, magnetic mines and butterfly bombs. the first they fumbled away and had not built up enough numbers, the latter my understanding they did not understand the damaging effects.

the magnetic mine would eventually be figured out, although months delay would be impactful, the butterfly bombs? not sure the countermeasures against those? like tossing sand into a machine, it will muck up the works if dropped on the British ports.
 
Regarding the British reaction to a buildup of German marine naval patrol aircraft, I refer you to the bottom of page 4.

"Pargraph 10. Aircraft carriers. That the effect on naval warfare, especially in the narrow seas, of the very recent developments in the range and power of aircraft referred
to in the memorandum by the Secretary of State for Air (CP. 27 (36)), should receive early consideration, but that in the meantime the proposals for the construction of four new carriers (some of a smaller type) within the period 1936-42 should provisionally be approved.
It would be advisable to limit the reference in the White Paper to. the numbers of aircraft carriers to the one small carrier to be included in the 1936 programme."


http://filestore.nationalarchives.gov.uk/pdfs/small/cab-23-83-cc-10-36-10.pdf

Note this is not only OTL, this is OTL in February 1936 under the government of Stanley Baldwin.
That recommendation comes from a Cabinet Paper called Programmes for the Defence Services dated 12th February 1936 and includes the Third Report of the Defence Requirements Sub-Committee of the Committed of Imperial Defence, or for short the D.R.C. 3rd Report. It can be downloaded from the National Archives website and its reference is CAB.24.259 (0026).

This is what I has to say about aircraft carriers. Bear in mind that the Second London Naval Treaty was still in force. The Second London Naval Conference had begun on 9th December 1935, but the resulting Second London Naval Treaty would not be signed until 25th March 1936.

Aircraft Carriers.png


So the small aircraft carrier was actually what became the 23,000 ton Illustrious class. Further more one "small carrier" wasn't included in the 1936 Programme, two were and two more were in the 1937 Programme. These were Illustrious, Victorious, Formidable and Indomitable, but because I haven't checked my spreadsheet not necessarily in that order.


Paragraph 54.png
 
The Germans were facing several allied technological advantages (little snowballs) that then merged into one large, devastating snowball that continued to grow. Furthermore, the Germans did not have a clear understanding of each little snowball.

Maybe...

Develop a good understanding of some of the little snowballs. Some snowballs such as better aircraft, escort carriers, more numerous escorts had no German counter measures. But...better countermeasures against some smaller snowballs could be implemented. This would shrink the size of the big snowball. For example:

- Radar: Allied radar (British invention) was developing very fast. German counter measure (METOX) was horrible. Drove crews mad with the noise, false alarms, and failure to detect real aircraft. It was also designed by a French company under German occupation. The French engineers had no cause to innovate. Move production and design back to Germany, get an effective METOX 2.

Stealth- what about stealthily shaped conning towers plated in 1940s stealth material (foams)?

Decoys: Maybe more innovative decoys. How about a conning tower shipped ballon anchored to a sea drag. Ballon inmates and lasts for days. U boats release them by the dozens. Some U boats are detailed to just release balloons. Could the balloons be released while a modified U boat was submerged? Each one must be investigated by an allied aircraft.

Huff Duff Decoys: Same concept as a balloon. It is a float with a crude radio and battery on it. Makes transmissions every so often. Each float lasts for days and must be investigated.

- Huff Duff: Allied radio triangulation abilities got better and better and in the end, could be mounted on escorts- real time fixes of U boat positions. Could radios be made to frequency hop to reduce Huff Duff? What about burst transmissions?
 
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Deleted member 1487

- Radar: Allied radar (British invention) was developing very fast. German counter measure (METOX) was horrible. Drove crews mad with the noise, false alarms, and failure to detect real aircraft. It was also designed by a French company under German occupation. The French engineers had no cause to innovate. Move production and design back to Germany, get an effective METOX 2.
British invention?
https://www.radarpages.co.uk/download/AUACSC0609F97-3.pdf

Metox was manufactured by a French company under German contract, it doesn't necessarily mean it was a French design, in fact it probably wasn't.
It was also very effective, the problem is the British tricked the Germans into believing that the Allies could home in on the device, so it was shut off and negated all it's purpose:
https://en.wikipedia.org/wiki/Metox_radar_detector
The British developed radar systems of a different frequency band that Metox couldn't detect.
Eventually it was replaced by Naxos which could detect the next generation of British radar, but not the last wartime US innovation H2X:
https://en.wikipedia.org/wiki/Naxos_radar_detector
 
Fig8-2_sm.jpg


Gotta sink 'em all. 40 million gross tons will take a lot of sinking.


Don't have to sink tem all , just sink enough to slow them down the war effort to a standstill.
Every year minimum amount of tonnage had to transport just to keep UK-functioning , only amount above this could be used for offensive action against the Nazi.

39 million tons in 1940 vs 30 million needed = 9 million t = BoB /LEND LEASE & 13,038 t bombs

36 million tons in 1941 vs 29 million needed = 7 million t = LEND LEASE + NORTH AFRICA + 31,704t bombing

32 million tons in 1942 vs 28 million leaving = 4 million t = LEND LEASE + NORTH AFRICA & SICILY+ 47,122 t bombing

34 million tons in 1943 vs 27 million needed = 7 million t = ITALY & LW + 201,642 t bombing

42million tons in 1944 vs 26 million needed =16 million t = FRANCE & D-DAY + 914,622t bombing

47 million tons in 1945 vs 26 million needed = 21 million t = VICTORY EUROPE + 370,313t bombing


LL = LEND LEASE
NA = NORTH AFRICA
S= SICILY
DD = D-DAY
I = ITALY
Fr = FRANCE
VE= VICTORY EUROPE
 
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my view Axis HAD two weapons in 1940 that if better utilized would have changed the calculus, magnetic mines and butterfly bombs. the first they fumbled away and had not built up enough numbers, the latter my understanding they did not understand the damaging effects.

the magnetic mine would eventually be figured out, although months delay would be impactful, the butterfly bombs? not sure the countermeasures against those? like tossing sand into a machine, it will muck up the works if dropped on the British ports.

Don't have to sink tem all , just sink enough to slow them down the war effort to a standstill.
Every year minimum amount of tonnage had to transport just to keep UK-functioning , only amount above this could be used for offensive action against the Nazi.

that was my point, but further delay becomes almost as bad as destroy, as it becomes vicious cycle of (moderately) damaged ships laid up, bombed again.

do think human nature defined strategy in some regard as u-boat commanders wanted to torpedo ships but possibly keeping minefields in place along with saturation of Butterfly Bombs would have been more effective (considering fewer losses from their own side.)
 
Metox was manufactured by a French company under German contract, it doesn't necessarily mean it was a French design, in fact it probably wasn't.
In either case, my bet is that the French technicians and employees working on that project had very little incentive to innovate, recommend improvements, improve build quality etc. The Germans using a French company to either design and manufacture, or even to manufacture Metox was more poorly conceived than the United Kingdom deciding at the same time that:

- System "S" is very important to our war effort.
- Lets contract the project out to a company in.... Spain. Spain, after all, is neutral-right?

Even before the radar frequency change, METOX was a bad design prone to give false alarms, emitted a loud warbling noise, and as it had to be disassembled and carried into the boat during a crash dive, prone to get damaged.
 
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Deleted member 1487

In either case, my bet is that the French technicians and employees working on that project had very little incentive to innovate, recommend improvements, improve build quality etc. The Germans using a French company to either design and manufacture, or even to manufacture Metox was more poorly conceived than the United Kingdom deciding at the same time that:

- System "S" is very important to our war effort.
- Lets contract the project out to a company in.... Spain. Spain, after all, is neutral-right?

Even before the radar frequency change, METOX was a bad design prone to give false alarms, emitted a loud warbling noise, and as it had to be disassembled and carried into the boat during a crash dive, prone to get damaged.
Thing is Metox worked; the 'false reports' were a function of it also picking up similar German transmissions, which modifications fixed. It was only rendered obsolete by the change in British radar power, which led to the Germans to introduce Naxos. The Germans were developing the device, not the French. The French successfully built a bunch of stuff for the Germans during the war, not as well as German workers or foreign workers in Germany, but there was limited capacity in Germany, so there was a point at which they had to outsource (the Brits did that too with the Americans; proximity fuzes, the cavity magnetron, even the atom bomb).
 
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hipper

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Don't have to sink tem all , just sink enough to slow them down the war effort to a standstill.
Every year minimum amount of tonnage had to transport just to keep UK-functioning , only amount above this could be used for offensive action against the Nazi.

39 million tons in 1940 vs 30 million needed = 9 million t = BoB /LEND LEASE & 13,038 t bombs

36 million tons in 1941 vs 29 million needed = 7 million t = LEND LEASE + NORTH AFRICA + 31,704t bombing

32 million tons in 1942 vs 28 million leaving = 4 million t = LEND LEASE + NORTH AFRICA & SICILY+ 47,122 t bombing

34 million tons in 1943 vs 27 million needed = 7 million t = ITALY & LW + 201,642 t bombing

42million tons in 1944 vs 26 million needed =16 million t = FRANCE & D-DAY + 914,622t bombing

47 million tons in 1945 vs 26 million needed = 21 million t = VICTORY EUROPE + 370,313t bombing


LL = LEND LEASE
NA = NORTH AFRICA
S= SICILY
DD = D-DAY
I = ITALY
Fr = FRANCE
VE= VICTORY EUROPE

Your figures are in error and the method of calculation is bizarre British imports were a minimum of 23 million tonnes in 1942
Which was enough to run the War economy

Look at British war economy statistics for some real figures

http://www.ibiblio.org/hyperwar/UN/UK/UK-Civil-WarEcon/UK-Civil-WarEcon-Stats-2.html
 
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Your figures are a loff and the method of calculation is bizarre and incorrect British imports were a minimum of 23 million tonnes in 1942
Which was enough to run the War economy

Look at British war economy statistics for some real figures

http://www.ibiblio.org/hyperwar/UN/UK/UK-Civil-WarEcon/UK-Civil-WarEcon-Stats-2.html


The only tonnage figures in there report 23 million tons dry goods delivered 1942, while 10 million tons liquid goods was also delivered [Oxford companion to WW-II. How much of that delivery was actual part of the war effort and how much for self defence.
 

Ian_W

Banned
The only tonnage figures in there report 23 million tons dry goods delivered 1942, while 10 million tons liquid goods was also delivered [Oxford companion to WW-II. How much of that delivery was actual part of the war effort and how much for self defence.

Section (e) even splits tanker and non-tanker imports ... and tells you how much volume was food and how much volume munitions.
 
what is the most feasible pre-war torpedo development? even if they did not launch huge provocative buildup of u-boats some further development of torpedoes could have been made.

my view the late war wire guided spinne torpedo seems logical since they had wire guided FL-Boats from WWI?

edit: oops, forgot to mention Elefant in room, testing OTL torpedoes to correct flaws. had whole scenario in my head that experiments with wire guidance they would discover problems with pins?
 
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