Better German naval strategy 1930-1945?

[z42]

But if there's one thing that needs to change in German naval strategy to make the greatest impact, it's in secure communications between HQ and the uboats. So, in the 1930s the Naval Intelligence Service instructs the B-Dienst to thoroughly investigate the Enigma device for design and operational vulnerabilities.

Vulnerabilities of the Enigma Machine

If by the time WW2 starts, the navy's encryption has addressed many of the vulnerabilities listed above, the German navy will be much harder to counter.

Another related change that would have a big impact is greater independence and communication blackouts for ships and uboats on operations. Had Lutjens kept his mouth shut, Bismarck might have made Brest, for example. So, instead of micromanaging the uboats, the boats are sent out into known convoy routes to conduct independent ops. Wolf packs wouldn't be as organized.

I think what was done at Bletchley Park was such an astounding achievement that a scenario that assumes a German 'red team' figures out how to crack the Enigma in the same fashion is far beyond any kind of plausibility.

However, I agree adopting a doctrine that assumes all radio communications to be plausibly compromised is something they could have done, without having to figure out if and how the Enigma is compromised.

 

[Admiral Beez]

I think what was done at Bletchley Park was such an astounding achievement that a scenario that assumes a German 'red team' figures out how to crack the Enigma in the same fashion is far beyond any kind of plausibility.

The Poles had it cracked before the war. The Polish cryptographers who cracked the Enigma code Having the Germans discover the vulnerabilities exploited by the Poles is plausible.

But agreed, better SOPs for communications would have make these vulnerabilities less important. A dozen subs are sent out to XY coordinates to hunt and then return. No encrypted radio communication between subs or HQ until back at port.

 

[EwenS]

In the first half of WW2 the problem with Ultra intelligence, especially that generated from the naval Enigma machines, was the length of time it took to get results. So it was of little immediate tactical use.

Enigma - Allied breaking of Naval Enigma - Technical pages - German U-boats of WWII - Kriegsmarine - uboat.net

The U-boat War in World War Two (Kriegsmarine, 1939-1945) and World War One (Kaiserliche Marine, 1914-1918) and the Allied efforts to counter the threat. Over 40.000 pages on the officers, the boats, technology and the Allied efforts to counter the U-boat threat.

uboat.net

Of much greater immediate use was the direction finding information produced by the Y service intercepting the U-boat chatter. That allowed, amongst other things, defensive routing of convoys, to avoid U-boat concentrations.

Y service - Wikipedia

en.m.wikipedia.org

The problem for the KM was that a certain amount of radio chatter was unavoidable as part of the Wolf Pack tactics. Signals had to be sent out to U-boats to form lines across a convoy's path. A U-boat's line of sight from just above the waves in pre-radar days was exceptionally limited. Once a convoy was found homing signals were necessary to bring in the rest of the Pack. Once a convoy had passed the patrol line had to be repositioned for the next convoy. Yes some reduction in chatter should have been possible.

Sending U-boat packs out in the hope of intercepting a single convoy and bringing them home again would not have been an efficient use of their time. If the convoy is missed then the whole sortie would have been wasted. Not every convoy could be interdepted. Covering the whole North Atlantic represented a different problem from that experienced by USN sub packs in the Pacific in 1944/45 where Japanese convoys followed more defined routes.

U-boats also performed a useful, to the Germans, weather reporting role. Amongst other things that aided Luftwaffe operations not only over Britain but also the Continent as well as allowing them to predict when Allied bombers might be flying. Ahead of D-Day an effort was made to deny that information to them. (Weather reporting grew in importance for the Allies as well. The number of RAF units grew and expanded as the war went on not only over the Continent but out into the Atlantic for forecasting purposes). The Germans established weather reporting stations, some manned & some unmanned, in places as far West as Greenland & the Labrador coast to assist their operations.

 

[Zmauky]

A radical solution to the "problem" of S&G being undergunned and not getting involved in changing turrets (and everything else that goes with it) is to sell them to the Dutch. Historically, in 1940, a contract was concluded on the transfer of technology for the battlecrusier (S&G), with a somewhat modified project. Wiki says that the Netherlands started (unsuccessful) projects even before 1938. So ... with a little thought out politics/business why not sell even unfinished (or just completed) S&G say between 1936 -1937. And the money obtained from the sale can be used immediately for 3rd and 4th Bismarck-class BBs (and much smoother construction of the first two).There would be some problems with the capacity of the shipyard, but...
With 4 modern Bismarck-class battleships in 1940/1, the Kriegsmarine ceases to be a fleet in being and becomes a real threat to the RN (at least for a while).

 

[z42]

A radical solution to the "problem" of S&G being undergunned and not getting involved in changing turrets (and everything else that goes with it) is to sell them to the Dutch. Historically, in 1940, a contract was concluded on the transfer of technology for the battlecrusier (S&G), with a somewhat modified project. Wiki says that the Netherlands started (unsuccessful) projects even before 1938. So ... with a little thought out politics/business why not sell even unfinished (or just completed) S&G say between 1936 -1937. And the money obtained from the sale can be used immediately for 3rd and 4th Bismarck-class BBs (and much smoother construction of the first two).There would be some problems with the capacity of the shipyard, but...
With 4 modern Bismarck-class battleships in 1940/1, the Kriegsmarine ceases to be a fleet in being and becomes a real threat to the RN (at least for a while).

Historically, much of the Dutch Navy in European waters joined the RN when the Netherlands was overrun by Germany in 1940. So a likely result of this scenario would be the same, with S&G joining the RN. Or participating in the defense of the DEI together with the Allies against the Japanese onslaught.

4 Bismarck class ships would undoubtedly be more powerful than the historical, but would they all be ready and potentially do something useful before the KM is boxed into harbors and fjords?

 

[Zmauky]

I think that the intention of the Dutch was to strengthen the defense of the DEI so that the problem was transferred to the Japanese (who solved similar problem -British KGV and Repulse- quite successfully).
A more nervous RN means a freer hand for Italy in the Mediterranean.
The Kriegsmarine cannot win the war alone anyway.
But more UK resources spent on parrying the stronger BB Kriegsmarine fleet means less ASW ships and perhaps most importantly probably no artic convoys either. Who would sail to Russia with 3-4 Bismarcks in Norway?
Easing the pressure on the Wermacht in Russia (let's not forget the first British tanks took part in the Russian counterattack near Moscow) would be perhaps Kriegsmarine greatest achievement -when she didn't help much in Baltic during the push towards Leningrad.

 

[Admiral Beez]

Or participating in the defense of the DEI together with the Allies against the Japanese onslaught.

The Dutch Scharnhorsts will go to the DEI. That will make Java Sea more interesting. And Japan will be royally peeved at Berlin for dramatically reinforcing the Dutch Navy in the region. Presumably both would need to be maintained or refitted at Singapore. If Germany can somehow defeat France without invading the Netherlands, a neutral Dutch government presents new questions.

 

[z42]

The Dutch Scharnhorsts will go to the DEI. That will make Java Sea more interesting. And Japan will be royally peeved at Berlin for dramatically reinforcing the Dutch Navy in the region. Presumably both would need to be maintained or refitted at Singapore.

I guess that depends on the timeline. Presumably the Dutch S&G will join the RN when the Netherlands are overrun in 1940. But will they be ready for operations at that time, or are they still fitting out, training crews etc. And at that point, why send them to the DEI? At that time, all the prospective action is up in Europe, and the Pacific is still peaceful. By the time they realize Japan might attack and start preparing for it (~November 41?), will there be time to prepare the S&G and send them to the DEI before the Java sea battle (Feb 27th 42)?

If Germany can somehow defeat France without invading the Netherlands, a neutral Dutch government presents new questions.

Hard to see the Dutch managing to stay neutral in the European war after Pearl Harbor when everyone declares against each other.

 

[z42]

(Missed commenting on this earlier..)

In the 1930s and in WW2, Germany needed more and better uboats to slow the convoys. Move asap away from the small Type II to much larger submarines. Even the 220ft long, 770 ton workhorse Type VII is too small, when at the same time the RN were operating 270ft, 1300 ton T-class. The French and Italian boats were also larger, not to mention the big USN and IJN boats. Germany needs uboats that can remain at sea for long periods with sufficient armament, fuel, food and crew amenities.

If they had something like really long range subs those could have been alternatives to surface warships for hunting lone merchantmen in the South Atlantic or even the Indian Ocean (like the raids by the Panzerschiffes)? Though without floatplanes and the u-boat conning tower close to the surface the u-boat will be much less likely to see nearby merchantmen.

And skip the battleships and put that steel, copper, etc, into uboats, plus hundreds of more tanks, trucks, and whatever helps with Barbarossa. If there's no Deutschlands, Scharnhorsts or Bismarcks it will be interesting to see what the Royal Navy builds. Will Ark Royal, the Illustrious and KGV classes be built as per history? Are the Revenge class decomissioned into reserve? And can Germany take Norway with only the Hippers, CLs and DDs?

I guess it would be the Deutschlands instead of the Hippers, but yes. The RN would have a field day if they'd find the invasion fleet without capital ships nearby for protection.

 

[Admiral Beez]

If they had something like really long range subs those could have been alternatives to surface warships for hunting lone merchantmen in the South Atlantic or even the Indian Ocean

Agreed. I think we don't appreciate how small German U-boats were compared to the submarines in the other navies....

The most numerous classes of U-boat, the Type VIIC had a surface displacement 760 tons with an external length of 220ft and beam 20ft. The most produced British submarine during World War II, the T-class, had a surface displacement of 1,290 tons, and was 276 ft long, 25.5 ft wide. Even the later, larger, and less numerous Type IX uboat was still notably smaller at 1,010 ton surfaced, and closer in size to the Italian Mediterranean-focused boats rather than open ocean craft. Imagine if Germany had boats equal to the USN's 1,525 ton, and 311ft long Gato class, shown below alongside a Type VIIC.

Check out the tech and habitability of the Gato class. This is what the Germans needed to be building from 1940 onwards.


View: https://www.youtube.com/watch?v=FctRpaleRFc

 

[Shortround6]

This is what the Germans needed to be building from 1940 onwards.

Why???

The Germans were not trying to just cross several thousands of miles of ocean just to get near the British/allied convoy routes.

With the capture of France the routes got a lot shorter. It was around 900-1000 miles to go from Western German ports to the West of Scotland. It was several hunderd miles shorter to go from Brest to the same area and only about 300 miles from Brest to the south coast of Ireland.

American boats were not bad at diving but they weren't real good either. American boats would have suffered more from air attacks. Planes would have gotten 5-15 seconds closer from sighting to sub submerging. This is lot dependent on sub size. There things they could to do tweak dive times but it just takes longer to submerge a bigger boat.
Some German boats had cut way decks to speed thing up.

Makes things a little more awkward for docking.
The small, vs medium, vs large boats in the Med were a problem for the British, the T boats and the older big boats got hammered in the Med. They were easier to see in clear water, dived slower, and didn't turn as quick. The small U & V class boats were actually better for the Med.

The American boats did a great job. They also would have suffered higher losses against an enemy that had their ASW stuff together.
Bigger boats are easier to detect with sonar.

 

[marathag]

data from Wiki

General characteristics Type
Type:	Type VIIB U-boat	Diesel-electric submarine P Class SS 176-181
Displacement:	753 t (741 long tons) surfaced 857 t (843 long tons) submerged	1,350 tons (1,372 t) standard, surfaced,[3] 1,997 tons (2,029 t) submerged[3]
Length:	66.50 m (218 ft 2 in) o/a 48.80 m (160 ft 1 in) pressure hull	289 ft (88 m) (waterline) 301 ft (92 m) (overall)[4]
Beam:	6.20 m (20 ft 4 in) o/a 4.70 m (15 ft 5 in) pressure hull	25 ft ⅞ in (7.6 m)[3]
Draft:	4.74 m (15 ft 7 in)	15 ft (4.6 m)[3]
Propulsion:	2 × supercharged 6-cylinder 4-stroke diesel engines totalling 2,800–3,200 PS (2,100–2,400 kW; 2,800–3,200 shp). Max rpm: 470–490[1] 2 x 750 PS (550 kW; 740 shp) (electric) 2 shafts	4 × Winton Model 16-201A 16-cylinder two-cycle[6] diesel engines, 1,300 hp (0.97 MW) each,[7] driving electrical generators through reduction gears,[2][8] 2 × 120-cell Gould AMTX33HB batteries,[9] 8 × General Electric electric motors, 538 hp (401 kW) each,[9] 2 × General Motors six-cylinder four-cycle 6-241 auxiliary diesels[7]
Speed:	17.7 knots (32.8 km/h; 20.4 mph) surfaced[1] 7.6 knots (14.1 km/h; 8.7 mph) submerged[1]	19.25 kn (35.65 km/h) surfaced,[3] 8.75 kn (16.21 km/h) submerged[3]
Range:	8,700 nmi (16,112 km; 10,012 mi) at 10 knots (19 km/h; 12 mph)surfaced 90 nmi (170 km; 100 mi) at 4 knots (7.4 km/h; 4.6 mph) 12 hours	SS-176-181: 11,000 nautical miles (20,000 km) surfaced at 10 knots (19 km/h)[3] 10 hours @ 5 kn (9.3 km/h), 36 hours @ minimum speed submerged[3]
Test depth:	230 m (750 ft). Calculated crush depth: 250–295 m (820–968 ft)	250 ft (80 m)[3]
Complement:	4 officers, 40 to 56 enlisted	5 officers, 45 enlisted[3]
Armament:	5 × 53.3 cm (21 in) torpedo tubes (four bow, one stern) 14 torpedoes or 26 TMA mines or 39 TMB mines 1 × 8.8 cm (3.46 in) deck gun (220 rounds) 1 × 2 cm (0.79 in) C/30 anti-aircraft gun	6 × 21 inch (533 mm) torpedo tubes (four forward, two aft) some fitted with two external tubes during the War 16 torpedoes [3] 1 × 3 inch (76mm)/50 caliber deck gun, later 4 inch [3] 2 × .50-caliber (12.7 mm) machine guns 4 × .30-caliber (7.62 mm) machine guns

It's not apparent from the stats, but the US Boats were far more habitable than any German sub, had better storage for food, plus air conditioning, for comfort and removing excess humidity, so fewer electrical shorts from condensation.
Keeping humidity controlled also allowed the Torpedo Data Computer to be fitted, an analog electromechanical calculator to make targeting far easier, and during the War were retrofitted with air and surface search Radar sets

Generally only the forward torpedo section had to hotbunk. Had Two freshwater showers, and a washing machine, plus freezer and refrigeration, too

The 'P Class' were mid '30s designs, The concurrent S-Class built at the same time were nearly identical, but Electric Boat pioneered all welded construction, while the P Class built at Navy Yards still had some riveting

 

[Thumpalumpacus]

I think the Germans would've benefitted from having at least some larger, longer-range U-boats on hand, Paukenschlag without needing milch-cows, would likely have been more efficient.

 

[EwenS]

I think the Germans would've benefitted from having at least some larger, longer-range U-boats on hand, Paukenschlag without needing milch-cows, would likely have been more efficient.

The KM did have a larger boat - the Type IX and its derivatives. The 6 Type IX entered service between Aug 1938 and Nov 1939 to be followed by 14 improved IXB through to the end of 1940, to be followed by the IXC in 1941. Range started at 10,500 miles at 10 knots and steadily increased.

There were also a small number of the long range Type XB minelayers completed 1941-44. Range 18,450 at 10 knots.

Details of all U-boat types can be found here.

U-boat Types - German U-boats of WWII - Kriegsmarine - uboat.net

The U-boat War in World War Two (Kriegsmarine, 1939-1945) and World War One (Kaiserliche Marine, 1914-1918) and the Allied efforts to counter the threat. Over 40.000 pages on the officers, the boats, technology and the Allied efforts to counter the U-boat threat.

uboat.net

Note how as each type evolved the range increased.

Edit - note the US P class, details of which were given above, completed 1936/37. That falls between the last of the Type VIIA and the first of the Type VIIB.

Edit 2 The first U-boats assigned to Operation Drumbeat were Type IX (5 of the 6 then available) and that Type formed the core of the early follow up waves both to the US coast and the Caribbean.

 

[Admiral Beez]

data from Wiki

I wish Wikipedia would keep a consistent UOM order. Sometimes they lead with metric, sometimes imperial. Sometimes displacement is tons, tonnes short tons or long tons. And don't get me started on aircraft specs, where one will give us wing area or rate of climb, but others will give us just wingspan and speed. It's as if the folks at Wikipedia don't want to facilitate apples to apples comparisons. Yes, Wikipedia is contributor-driven, but the system could force the sequence of data and refuse incomplete submissions.

 

[Thumpalumpacus]

The KM did have a larger boat - the Type IX and its derivatives.

You've clearly misunderstood; we were talking about boats larger than those being potentially useful.

 

[Shortround6]

Subs would work for long distance cruisers, they just had problems. One was vision.
If you have a sub where the lookouts are 20ft above the water (a little low) the visual horizon is about 5.5 miles. If you have a freighter bridge 50ft high you have a horizon 0f 8.7 miles and if you can get a look out up at 70ft the horizon is 10.3 miles.
Most subs didn't have radar in the early part of the war and radar worked better for the Americans than it did for the Germans or Japanese. American subs had radar before most Japanese destroyers did and they had better radar, not a 100% guarantee but the US boats could probably detect the Japanese ships before the Japanese detected the Americans.
Germans did not have that advantage, or at least not often and/or not for long.

As note by other, food for long voyages was problem. Condensation was problem. For the Germans in the North Atlantic the condensation was problem, actually cooling the sub due to heat was a much lesser problem than the tropics.
The German type IXs were designed for distance waters and had a few problems in the NA. Depending on exact version about 8 torpedoes out of 22 were stored in tubes under the deck. The Sub had to surface and go through a long/laborious/dangerous process of getting the torpedoes into the hull.

Notice the possible tube just forward of the conning tower. This does not look like "fun" even tied to dock. In a rolling sea at winter in the NA?
Warm calm day in the tropics, not too bad..................................If a PBY doesn't come along with the hatch open and the torpedo half in and half out.

A Type IX could crash dive in about 35 seconds, Type VIIs could do it in about 25-30 seconds. Equivalent British boats were a bit faster, US subs were slower, some Japanese subs could send out written invitations.

For the Germans there were only so many slips that could build the larger boats. Yes you can lengthen some slips.
Is a German Gato worth it? Are 2 Gatos worth 3 Type IXs or 2 Gatos worth 4 Type VIIs?

 

[Thumpalumpacus]

Subs would work for long distance cruisers, they just had problems. One was vision.
If you have a sub where the lookouts are 20ft above the water (a little low) the visual horizon is about 5.5 miles. If you have a freighter bridge 50ft high you have a horizon 0f 8.7 miles and if you can get a look out up at 70ft the horizon is 10.3 miles.
Most subs didn't have radar in the early part of the war and radar worked better for the Americans than it did for the Germans or Japanese. American subs had radar before most Japanese destroyers did and they had better radar, not a 100% guarantee but the US boats could probably detect the Japanese ships before the Japanese detected the Americans.
Germans did not have that advantage, or at least not often and/or not for long.

As note by other, food for long voyages was problem. Condensation was problem. For the Germans in the North Atlantic the condensation was problem, actually cooling the sub due to heat was a much lesser problem than the tropics.
The German type IXs were designed for distance waters and had a few problems in the NA. Depending on exact version about 8 torpedoes out of 22 were stored in tubes under the deck. The Sub had to surface and go through a long/laborious/dangerous process of getting the torpedoes into the hull.
View attachment 767248
Notice the possible tube just forward of the conning tower. This does not look like "fun" even tied to dock. In a rolling sea at winter in the NA?
Warm calm day in the tropics, not too bad..................................If a PBY doesn't come along with the hatch open and the torpedo half in and half out.

A Type IX could crash dive in about 35 seconds, Type VIIs could do it in about 25-30 seconds. Equivalent British boats were a bit faster, US subs were slower, some Japanese subs could send out written invitations.

For the Germans there were only so many slips that could build the larger boats. Yes you can lengthen some slips.
Is a German Gato worth it? Are 2 Gatos worth 3 Type IXs or 2 Gatos worth 4 Type VIIs?

Longer time on station due to larger supply stocks/fuel tanks/crew comforts is a force-multiplier. Whether it's worth it financially or otherwise, I couldn't say.

 

[Shortround6]

Longer time on station due to larger supply stocks/fuel tanks/crew comforts is a force-multiplier. Whether it's worth it financially or otherwise, I couldn't say.

It is, however the torpedo supply is also important. So is having engines/machinery that will last reliably for the longer patrols.
But so is stealth.
Larger boats are better radar targets on the surface, they are better visual targets. They are better sonar targets under water (maybe by only a few hundred yds and depending on aspect (sideways vs end on).

Perhaps some larger boats than the Early type IXs would have been useful. Assuming they didn't cut into production of Type VIIs to much in the early years. For the Germans there several stages in the development of ASW warfare. Large changes. The Germans and Japanese never got anywhere near the level of ASW that the Americans and British did in 1943. Italians were skillful (a lot of practice) but their 1943 exit and their backwards electronics rather limits their end results.

The British managed to cram air conditioning into some of the Ts and maybe some S's (?) the saving in manpower was huge. They went to using a single crew per boat instead of 2 crews per boat and rotating them. In the tropics many of the crew preferred sleeping on the air conditioned boats rather than sleeping on the non air-conditioned depot ships. Cram is a accurate word as they originally thought they would have to lengthen the boats 6-10ft (?) to fit the air conditioning in. Subs usually don't have much spare room for much of anything.

 

[z42]

I don't think the question here is smaller u-boats (Mk VIII) vs. larger ones (Mk IX, or some hypothetical even larger one) in the North Atlantic a few hundred nm from occupied France, but rather does the bigger boat bring some new capability that is infeasible or very difficult or inefficient to provide with smaller boats. So for operating in the Caribbean, South Atlantic, Gulf of Mexico(?), Indian ocean, the smaller boat might not be an option at all.

A surface warship might be an alternative to a long range u-boat in some cases, like in the South Atlantic or Indian Ocean. A surface warship will be able to see much further thanks to a being higher over the surface. Particularly if it has floatplanes. OTOH you can build quite many even large u-boats for the cost of a surface raider like a Deutschland class ship. And once the Allies get long range air patrols going I guess the days of surface raiders are pretty much numbered. Patrol aircraft might make life sour for u-boats too, but they have at least some chance of escape.