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

Deleted member 1487

So the Germans start producing additional U-boats in contravention of the AGNA. The British start their rearmament earlier, harder and faster in response which means they run out of funds sooner than OTL. How does that factor into things?

In addition does building extra U-boats prove to be the straw that broke the camels back for the German economy?
The Germans broke the AGNA in early 1939 with Plan-Z, but started to build a bunch of heavy capital ships that ended up scrapped in November 1939; had they opted instead to start building Uboats they could have had more operational as of 1940, when it really started to matter. At that point the British thought they really only needed to worry about uboats when their numbers totaled over 100% of British submarine tonnage, which new constructions possible in early 1939 would not really exceed; you would only really start getting a British response when they realized just how badly they misunderstood the threat in 1940 when things were too late to respond quickly.
 
Build far more very long range Patrol Aircraft capable of bombing a merchant man - so try to get the Amerika Bombers that were actually built into service earlier as LRMPA and build more of them.

I's assume the planes would only be effective after the Germans took France. Protection of bases there could be a problem.

More U-Boats is an issue because building more U-Boats beyond the 45% parity allowed by the Anglo German Naval Agreement (AGNA) sets of that special alarm in Whitehall because as far as the British are concerned U-Boats have but one job and that is the Blockade of the UK

I wonder if the Germans could've circumvented this issue with a bit of sneakiness. I don't know if the AGNA forbade German production of U-boats as well as KM numbers. Maybe, beginning in 1936-37, the Germans could've built far more U-boats, supposedly for sale to other navies like the Japanese and Italian. In this scenario, by secret prearrangement, certain nations allied to the reich would place bogus "orders" to Blom and Voss for u-boats, but the Germans would actually pay for them and later use them.

More raiders - build more merchant ships capable of quickly being converted to merchant raiders than OTL in time of war - this is the one thing that can possibly be hidden from the rest of the world and in any case would not in and off itself break the word of any treaty.

More AMCs wouldn't be necessary if more u-boats could be built, either by bamboozling the British in the manner suggested above, or maybe by building vital components for u-boats, and stashing them away until, the AGNA runs it course. The reich might've assembled far more boats by 1939-40.

Build long range cruisers capable of acting as raiders in time of war - make them good enough to sink shipping - so armed with 5.9s and fast enough to run from anything bigger than them

Same for that.
 
The British started running out of funds (gold and US$) because they delayed rearmament and had to throw a lot of money at the problem that until US Lend Lease could only be bought from the USA with US$ or Gold once the war had started

A percentage or 2 increase in the military budget over that of OTL in 1938 is worth many times that in 1939 - the same extra extra money in 1937!!!! - To put it into context in 1938 the Military spending of the UK was just 4% of the Budget and remember that this involved maintaining the world's largest navy.

Basically an earlier modest increase in the military spending in the UK would pay massive dividends to the ability of its war time industries to deliver the necessary items earlier than OTL.

With more time more of the machine tools for example could be built in the UK or bought before the war using normal pre-war foreign exchange methods

Germany was already using dubious accounting methods for its rapid rearmament - I think we are all agreed that without the 'loot' it gained from those nations it conquered / annexed it could not have maintained the scale of rearmament that it did.


Thank you for highlighting that. I’d always understood that the British were slow to rearm because they could not afford to do so faster. 4% of the budget on defense spending is not a lot!
 
Thank you for highlighting that. I’d always understood that the British were slow to rearm because they could not afford to do so faster. 4% of the budget on defense spending is not a lot!

They could not afford to do it earlier because the Cabinet where answerable to the house and the population they represented - not because the money was not there!

During peacetime they are responsible for long term decisions, social programs and spending the taxpayers monies in a correct and meaningful way - only in hindsight would a correct and meaningful way be to have spent more of the budget on the military

Not for them the squandering of massive fortunes on the military - only a dictatorship can do that.

I's assume the planes would only be effective after the Germans took France. Protection of bases there could be a problem.



I wonder if the Germans could've circumvented this issue with a bit of sneakiness. I don't know if the AGNA forbade German production of U-boats as well as KM numbers. Maybe, beginning in 1936-37, the Germans could've built far more U-boats, supposedly for sale to other navies like the Japanese and Italian. In this scenario, by secret prearrangement, certain nations allied to the reich would place bogus "orders" to Blom and Voss for u-boats, but the Germans would actually pay for them and later use them.



More AMCs wouldn't be necessary if more u-boats could be built, either by bamboozling the British in the manner suggested above, or maybe by building vital components for u-boats, and stashing them away until, the AGNA runs it course. The reich might've assembled far more boats by 1939-40.



Same for that.

Certainly - main priority though is to defeat France in a continental campaign - as for air bases I am unaware of any security issues during the German occupation of France so I am not sure what you mean?

The Germans were only just about able to keep up with their own production as it was and put yourself in the place of their Lordships at the British Admiralty - do you think such an idea would wash with them?

The British Intelligence (and that of other interested parties) where quite good at their job - the risk of any such a deception being discovered would be very high and if Germany was found to be cheating such a revelation would not only be a disaster but would like I said change British policy towards Germany earlier than it did OTL

Building 'Fat' Long ranged fast merchantmen suitable for conversion to a raider with built in hard points for deck guns and torpedo tubes is relatively easy and I would imagine easier to hide - and given that they did it OTL reinforces the idea!
 

BlondieBC

Banned
There is a lot of low hanging fruit. Others have listed, and I will go in order of impact, IMO.

1) Fix the Torpedoes prewar.
2) As soon as we break the Anglo-Naval Agreement, then focus on building U-boats.
3) Have a better encryption system. There is no reason the war could not be started with more rotors in the machine and better discipline procedures.
4) Have a good air dropped torpedo at the start of the war.
5) After France falls, give the naval war priority on air assets.
6) Don't squander the surface fleet on things like the Bismarck Trip. Keep the surface forces as Fleet in Being to a large extent.
7) Have better prewar plan.
 

BlondieBC

Banned
Doubtful. The Germany fleet could certainly have done better, as the OP asks, but how much better? Even if shipping losses are say 10-20% higher that's not by itself going to force the Churchill government to give in. And the idea is subject to the same problems that turn up in Sealion threads when people propose a bigger German surface fleet.
1. Where do the resources come from to build all these extra vessels? U-boats are small but they still require steel and rubber (the latter particularly scarce). Do they cut back on production of aircraft or vehicles to allow extra U-boats? What does that do to the France campaign or the Blitz?
2. When London notices all these extra U-boats being built in a great hurry (and they will notice) what does that do to their calculations? Does the Munich Agreement still happen if Germany is visibly preparing for a sea war on a bigger scale than OTL? Does the Admiralty shift its resources to building more escorts? Does the RAF become more amenable to allocating aircraft to Coastal Command? Does the US act more quickly to pass Lend-Lease?


Quite so, but that fact reflects something fundamental about Germany's strategic situation (in both world wars in fact) - the Navy was a solution in search of a problem. It could never be big enough when it was always the lower-priority service.

For a complete plan, all easy low hanging fruit, probably jump British losses by over 100%, and this should knock the UK out of the war.
 
More AMCs wouldn't be necessary if more u-boats could be built, either by bamboozling the British in the manner suggested above, or maybe by building vital components for u-boats, and stashing them away until, the AGNA runs it course. The reich might've assembled far more boats by 1939-40.



Same for that.

U-boats are a bit like carriers. They were nearly there in 1939 but not quite. AMCs and cruisers produced a reasonable return for the first half of the war. U-boats were short ranged and slow. While the struggle obviously swung back and foward, convoys prevented U-boats being that dangerous over the same time period.

Invest in a few AMCs and spread them across the world and the UK and French have to spread out their fleets more. That makes the U-boat's life easier in the east Atlantic. Throw a few lightish cruisers in and the Allies need to spread even more firepower around.

Combined warfare is always more interesting than concentration on one type of unit.
 

NoMommsen

Donor
So the Germans start producing additional U-boats in contravention of the AGNA. ...
...
An earlier abandonment on the AGNA (that is 35% parity with the Royal Navy on all surface vessels and 45% on U Boat numbers)...
Well ... reality and actual agreement looks different ... at first :
the AGNA did NOT count in 'numbers' but in tonnage only.

Fot what the germans were actually allowed in terms of sunbs ... read from wiki, the according 'chapter'of the text of this agreement :
(f) In the matter of submarines, however, Germany, while not exceeding the ratio of 35:100 in respect of total tonnage, shall have the right to possess a submarine tonnage equal to the total submarine tonnage possessed by the Members of the British Commonwealth of Nations. The German Government, however, undertake that, except in the circumstances indicated in the immediately following sentence, Germany's submarine tonnage shall not exceed 45 percent. of the total of that possessed by the Members of the British Commonwealth of Nations. The German Government reserve the right, in the event of a situation arising, which in their opinion, makes it necessary for Germany to avail herself of her right to a percentage of submarine tonnage exceeding the 45 per cent. above mentioned, to give notice this effect to His Majesty's Government in the United Kingdom, and agree that the matter shall be the subject of friendly discussion before the German Government exercise that right.
In short :
they were allowed 100 % of the commenwealth tonnage on subs. ... But for the moment agreed to restrain themself to 45 %.
A restaint to be reliefed by (simple) notice and some friendly discussion before welding the first plate.

And as it seem the Brits were prepared to accept this 100 % tonnage as something well within the abilities of the RN to deal with. Therefore it could be argued IMO, that if the germans start to (actually) build more subs in 1937/38, with the notification of not wanting to exceed ... lets say 70 or 75 %.

About the 'acceptance' of such a notification and rather low impact on british military ... 'countermeasures' :
  1. see not only above about the RN evaluation of sub-warfare in the interwar period (as of rather low importance)
  2. there is THE appeasement goverment atm ruling in Britain

I have no idea atm in how much subs of what type this might (be) tranlate(ed) into, but it would give the germans at least the possibility to ... prepare for even more to come.
 
U-boats are a bit like carriers. They were nearly there in 1939 but not quite. AMCs and cruisers produced a reasonable return for the first half of the war.

Essentially use of surface raiders ended in 1941.

U-boats were short ranged and slow. While the struggle obviously swung back and foward, convoys prevented U-boats being that dangerous over the same time period.

Type IXs were long ranged, and sank plenty of tonnage in remote areas without much convoying.

Invest in a few AMCs and spread them across the world and the UK and French have to spread out their fleets more. That makes the U-boat's life easier in the east Atlantic.

But the type of warship used to hunt raiders wasn't usually the type used for convoy escort (i.e. cruiser instead of corvette).

Combined warfare is always more interesting than concentration on one type of unit.

More interesting, yes. More effective?? Dunnooo....
 
They could not afford to do it earlier because the Cabinet where answerable to the house and the population they represented - not because the money was not there!

During peacetime they are responsible for long term decisions, social programs and spending the taxpayers monies in a correct and meaningful way - only in hindsight would a correct and meaningful way be to have spent more of the budget on the military

Not for them the squandering of massive fortunes on the military - only a dictatorship can do that.
Because of the 'anti-war' mentality in the electorate in the 1930's the government resorted to borrowing to fund rearmament. The worlds reserve currency can pretty well borrow whatever it wants. Most other countries at the time went 'the League of Nations will save us!' and they were the first ones taken over.
 
Certainly - main priority though is to defeat France in a continental campaign - as for air bases I am unaware of any security issues during the German occupation of France so I am not sure what you mean?

What I meant was, the RAF was a pretty tough opponent from the start and would've struck as hard as it could at German air bases in France, especially if their aircraft were sinking a lot of vital tonnage. It would've been tough for the Luftwaffe to provide adequate protection especially if Barbarossa occurs as per OTL.

The British Intelligence (and that of other interested parties) where quite good at their job - the risk of any such a deception being discovered would be very high and if Germany was found to be cheating such a revelation would not only be a disaster but would like I said change British policy towards Germany earlier than it did OTL

Yeah allied intelligence would've made the scheme risky. But I'd assume the Germans would've done a lot to make the deception work e.g. have foreign crews and diplomats inspect the "boats they ordered," put foreign markings, even in Japanese, on some U-boats etc. IMO the scheme would've had a good chance unless somebody ratted on them, and the Germans would've kept as few people as possible in the know about this.
Of course, assuming some of the extra boats were finished before the outbreak of war, the Germans would've trained their own men in them, but even that could've been disguised as "testing and evaluation" or something of that nature.

Building 'Fat' Long ranged fast merchantmen suitable for conversion to a raider with built in hard points for deck guns and torpedo tubes is relatively easy and I would imagine easier to hide - and given that they did it OTL reinforces the idea!

The problem is, the Germans were always at a big disadvantage in surface ship strength.In the early years of the war, both U-boats and raiders performed well. But note which of the two was able to fight on longer.
 
Well ... reality and actual agreement looks different ... at first :
the AGNA did NOT count in 'numbers' but in tonnage only.

Fot what the germans were actually allowed in terms of sunbs ... read from wiki, the according 'chapter'of the text of this agreement :

In short :
they were allowed 100 % of the commenwealth tonnage on subs. ... But for the moment agreed to restrain themself to 45 %.
A restaint to be reliefed by (simple) notice and some friendly discussion before welding the first plate.

And as it seem the Brits were prepared to accept this 100 % tonnage as something well within the abilities of the RN to deal with. Therefore it could be argued IMO, that if the germans start to (actually) build more subs in 1937/38, with the notification of not wanting to exceed ... lets say 70 or 75 %.

About the 'acceptance' of such a notification and rather low impact on british military ... 'countermeasures' :
  1. see not only above about the RN evaluation of sub-warfare in the interwar period (as of rather low importance)
  2. there is THE appeasement goverment atm ruling in Britain

I have no idea atm in how much subs of what type this might (be) tranlate(ed) into, but it would give the germans at least the possibility to ... prepare for even more to come.

Reality was that they did not build above 45% whatever the wording was.

If there was wiggle room and they wiggled then that 'friendly discussion' would at best involved forced fixed smiles on behalf of the British!

As far as the British are concerned U-Boats have one job - and Just because the Admiralty are Paranoid doesn't mean that Germany is not out to get them!
 

hipper

Banned
Well ... reality and actual agreement looks different ... at first :
the AGNA did NOT count in 'numbers' but in tonnage only.

Fot what the germans were actually allowed in terms of sunbs ... read from wiki, the according 'chapter'of the text of this agreement :

In short :
they were allowed 100 % of the commenwealth tonnage on subs. ... But for the moment agreed to restrain themself to 45 %.
A restaint to be reliefed by (simple) notice and some friendly discussion before welding the first plate.

And as it seem the Brits were prepared to accept this 100 % tonnage as something well within the abilities of the RN to deal with. Therefore it could be argued IMO, that if the germans start to (actually) build more subs in 1937/38, with the notification of not wanting to exceed ... lets say 70 or 75 %.

About the 'acceptance' of such a notification and rather low impact on british military ... 'countermeasures' :
  1. see not only above about the RN evaluation of sub-warfare in the interwar period (as of rather low importance)
  2. there is THE appeasement goverment atm ruling in Britain

I have no idea atm in how much subs of what type this might (be) tranlate(ed) into, but it would give the germans at least the possibility to ... prepare for even more to come.


The request to increase the size of the german Submarine fleet is an effective declaration of war both sides knew it.
 
More AMCs wouldn't be necessary if more u-boats could be built, either by bamboozling the British in the manner suggested above, or maybe by building vital components for u-boats, and stashing them away until, the AGNA runs it course. The reich might've assembled far more boats by 1939-40.

Building 'Fat' Long ranged fast merchantmen suitable for conversion to a raider with built in hard points for deck guns and torpedo tubes is relatively easy and I would imagine easier to hide - and given that they did it OTL reinforces the idea!

U-boats are a bit like carriers. They were nearly there in 1939 but not quite. AMCs and cruisers produced a reasonable return for the first half of the war. U-boats were short ranged and slow. While the struggle obviously swung back and foward, convoys prevented U-boats being that dangerous over the same time period.

Invest in a few AMCs and spread them across the world and the UK and French have to spread out their fleets more. That makes the U-boat's life easier in the east Atlantic. Throw a few lightish cruisers in and the Allies need to spread even more firepower around.

Essentially use of surface raiders ended in 1941.

But the type of warship used to hunt raiders wasn't usually the type used for convoy escort (i.e. cruiser instead of corvette).

The problem is, the Germans were always at a big disadvantage in surface ship strength.In the early years of the war, both U-boats and raiders performed well. But note which of the two was able to fight on longer.

made the point earlier that AMCs were treated as an afterthought. somewhat more powerful engines and they could have run down more ships OR made their escape. often hampered by museum piece WWI-era weapons (better used for coastal defense) all could carry the small S-boats.

some of same ships converted to AMCs were used as mine clearing Sperrbrecher, losing more than half of valuable 5,000t+ vessels until they realized 1,700 KSB ship would perform as well. (so pool of ships for conversion larger)

the KM light cruisers were failure, they intended Leipzig to begin raiding but was under repair. so the plan at least was for them to follow Panzerschiff? at least potential there for 5 modern LCs to supplement the larger ships raiding?
 
made the point earlier that AMCs were treated as an afterthought. somewhat more powerful engines and they could have run down more ships OR made their escape.

Even in that case the diving ability of a U-boat gave it the advantage of endurance. Even if an AMC could run down more ships or outrun an enemy warship, they'd squander a lot of fuel having to do those things. If the Germans could somehow prevent their supply ships from being lost, that would've been one thing, but assuming things go as in the OTL as regards that, subs would be the better bet. They don't necessarily have to chase an enemy, just submerge in his path and ambush him (or creep up to him at night, undetected because of the low profile). And they don't have to run on the surface a long way at high speed to evade an enemy. Just hide in the depths. Given the need to range far and wide in search of ships, and remain on station as long as possible, the added endurance conferred by a u-boat's diving ability (and stealth) was important. I don't think it was an accident that the u-boat was (essentially) the only weapon system of the KM that continued fighting after 1941.
 
Even in that case the diving ability of a U-boat gave it the advantage of endurance. Even if an AMC could run down more ships or outrun an enemy warship, they'd squander a lot of fuel having to do those things. If the Germans could somehow prevent their supply ships from being lost, that would've been one thing, but assuming things go as in the OTL as regards that, subs would be the better bet. They don't necessarily have to chase an enemy, just submerge in his path and ambush him (or creep up to him at night, undetected because of the low profile). And they don't have to run on the surface a long way at high speed to evade an enemy. Just hide in the depths. Given the need to range far and wide in search of ships, and remain on station as long as possible, the added endurance conferred by a u-boat's diving ability (and stealth) was important. I don't think it was an accident that the u-boat was (essentially) the only weapon system of the KM that continued fighting after 1941.

you are conflating what a proper building program for the KM should be and what tools they had to use in wartime. commercial ships (and you might also include FW-200 aircraft as they doubled as transports) have a value outside their usefulness as weapons.

while I might agree with the futility (and foolishness) of a Plan Z it would forego the lessons of WWI to plan on u-boats alone to defeat the Allies? btw they were also using S-boats until the end too.

you might also check out O'Hara's Struggle for the Middle Sea as the KM proved able to employ a motley crew fleet to great effect.
 

BlondieBC

Banned
Even in that case the diving ability of a U-boat gave it the advantage of endurance. Even if an AMC could run down more ships or outrun an enemy warship, they'd squander a lot of fuel having to do those things. If the Germans could somehow prevent their supply ships from being lost, that would've been one thing, but assuming things go as in the OTL as regards that, subs would be the better bet. They don't necessarily have to chase an enemy, just submerge in his path and ambush him (or creep up to him at night, undetected because of the low profile). And they don't have to run on the surface a long way at high speed to evade an enemy. Just hide in the depths. Given the need to range far and wide in search of ships, and remain on station as long as possible, the added endurance conferred by a u-boat's diving ability (and stealth) was important. I don't think it was an accident that the u-boat was (essentially) the only weapon system of the KM that continued fighting after 1941.

I did research on AMCs. They have about a 90 day expected life. We like to talk about the ones with multiple voyages. We forget all the AMC with life span measured in days or weeks.
 
I did research on AMCs. They have about a 90 day expected life. We like to talk about the ones with multiple voyages. We forget all the AMC with life span measured in days or weeks.

my view the main strategic issue is that the KM launched waves, the Panzerschiffe, then the AMCs, then the u-boats and to certain limited extent the Condors? with a handful of raids by the larger warships.

there never was a combined effort. the AMCs could never be expected to occupy center stage for long, especially without radar and proceeding below 20kts? (they needed a little more wolf, a little less sheep's clothing)

(of course the light cruisers were AWOL, so lackluster they never attempted raids)
 
in order for long range surface raiders to work they must approach from two different POV. Either they are disguised vessel and sail the seas secretly until they stumble on independent MV , or they are purpose built warships . The first group can be mobilised from indigenous merchant fleet fairly quickly during war time so are bit of a no brainer. Historically even with abandoning 1/2 their merchant fleet to getting caught overseas, the KM still had access to dozens of long range diesel powered merchant vessels. However many of these had top speeds of only 13-15 knots and were dismissed. The minimum top speed accepted was 16 knots. Why ? Don't know- but maybe to out run RN fleet cruising speeds of 15 knots? Or maybe just to catch up to average convoy @ 7-8 knots speed.

Anyway a couple dozen fit the description and some were converted into the HSK role , but many in the KM- didn't think the effort was worth much. If allowed ~ 20 could have been armed and crewed -as HSK- and deployed in the first year of hostilities.

With the warship role several capabilities appear to be at cross-purposes. You want to have many ships, which usually means small warships enough to be built in many ship yards. They have to be fast enough to catch a convoy and have enough endurance to range across the Atlantic - that suggests a larger warship. Once they reach said convoy they must be strong enough to defeat any convoy escorts and still have enough to chase down any fleeing MV. Fast long range warship with many big enough guns and lots of ammo- this suggests a bigger and bigger warship, which means fewer can be built.

Diesel power would seem a must to solve the endurance/bunkerage problem , while torpedoes can be installed in warships down to torpedo boat size and use these to sink merchants after the attack on the escorts. But German Destroyers and torpedo boat did not have diesels and were too limited with endurance. Its doubtful they could drive off convoy escorts except in the first years, when convoy escorts were a few small converted fishing trawlers. Some kind of Cruiser would seem to be the minimum warship size to work with....but which one?
 
I did research on AMCs. They have about a 90 day expected life. We like to talk about the ones with multiple voyages. We forget all the AMC with life span measured in days or weeks.

That's weird since this sight reports .....9 HSK conducted 12 cruises accumulating 3769 days at sea or an average of 314 days per cruise. Where does "90 day expected life" come from?

http://www.bismarck-class.dk/hilfskreuzer/hilfskreuzer_introduction.html

The prewar value placed on HSK was clearly derived from WW-I experiences.

https://archive.org/stream/ReviewOfGermanCruiserWarfare19141918#page/n1/mode/2up

according to the above site each warship raider averaged 10 kills and took 10-11 enemy warships [mostly CL] to hunt them down, while the HSK raiders averaged 9-10 kills and required ~ 10 warships although many were AMC & DD.

If the numbers in WW-II were to bare similar fruit , 20 HSK could have required a fleet of 200 AMC/DD to hunt them down after the HSK sank 200 enemy vessel's. That would be a worth while investment. I gather that the historical WW-II HSK missions accumulated 142 enemy vessels sunk or captured [& turned into other suede HSK] . That part looks better than WW-I record.
 
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