Hi Rich,
Now where did some of those graceless remarks come from?
Enrico is a widely published naval historian. I do not always agree with him, but we do manage a civil level of disputation and I do recognise that he has particular expertise in naval matters that I lack.
I only made some self deprecating remarks about my limitations in Enrico's area of specialisation. I was actually agreeing with you until Enrico shot me down, so how I might end up in your "insulting fool" category, is a mystery. An explanation would be appreciated.
Cheers,
Sid.
The type XXl........A war winner?
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Enrico Cernuschi
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Hello Rich,
take it easy, please, war is over.
I beg your pardon for my modest English. I'll try to be more understable.
When you begin the project of a submarine boat the first item to consider is the floating reserve.
A boat whose task is to fight afloat and to dive just to avoid the enemy reaction has got an high floating reserve (35%)
a boat which must sail most of her operative life under the sea level had got a low reserve (15%).
The first one (a VII or a IX type boat, just to do an example) is able to sail well on the surface and to cover at a reasonable speed with almost any time the long transfer voyages between her station and an enemy convoy just sighted by air recon or by cryptology analisys.
The second one (a XXI in our debate) is a poor boat surfaced and with the often very rought Atlantic waves would sail like a pig.
In theory a VII U Boote could do 16 knots as its best surface speed, actually it was not more than 12 (any machinery at top speed has got a very short life between two refits and may face breakdowns; top speed is used only when it mattered).
A XXI boat had, by the book, a 15,6 surfaced top speed, actually 12, as a consequence of her streamlined hull, ideal for underwater speed but havoc surfaced, she could do less than 10 rolling like hell (and we must consider the strain for the crew too).
Moral: the XXI was the necessary evolution of the submarine, as to go underwater was the only way to survive in front of the by now very efficient and deadly Allied ASW doctrine. The classic submarine of the First and Second World War was a dead man walking in 1943.
The real problem, anyway, was not to survive, but to decimate the convoys, like during the former happy times. Type XXI could survive after a single attack, but had quite more problems to catch the enemy convoys than the VII as it was slower and sailed worste.
It was much more difficoult to led mass attacks with the XXIs for the same reasons.
The XXI, once would be able to find (almost alone) hes target (a convoy, of course, not a slow straggler or a lone (slow again) freighter, statistical not existent in the upper Atlantic in 1943-1945 and which were at the mercy of any surfaced submarine, out fashioned too) could do a surface brilliant lone attack (maybe lauching in a single gulp all his 6 bow torpedoes with circling courses ect. statisic were against this system since 1942; as Adm. Andrew B. Cunningham, himself an excellent sailor, wrote in his memories "Ther's always more sea than ships") and, then, escape at hight speed avoiding enemy tetailation, but nothing more.
An hour of full speed underwater is enough to drain any batteries. At best you can do 20 minutes, than only creep. The theroical capacity is always quite under the real terms (batteries are capricious, today too; the electrical system suck power as vampires; they are fragile ect.) and any commander is quite prudent. Don't forget that it's impossible, in a cold sea like the Atlantic ocean, to stay underwater without the machinery going. This is a difficoult exercise in warm seas, but it's simply impossible in the cold ones, it's a matter of idrography and phisics.
The XXI was a natural evolution of submarine warfare; it was not the key for a renewed succesful strategy against the 1943-1945 convoys able to achieve the previous 1940-1943 successes.
During the last part of the war (1943-1945) a VII boat (or, better a wolfpack) could attack a convoy, but had a very hight chance to be sunk getting little in change.
A XXI boat had more problem than the VII (or even IX) to attack a convoy; she could do it almost alone (a copule at best); she could hope in a legitimate way to get a kill or, maybe, two; she could avoid enemy reaction almost in a sure way (a little optimistic, but we can concede it, for the first times at least); but could not do anything more as the convoy would be soon beyond her range and this little war had not a single chance to win the tonnage war gained by USA since the beginning of 1943.
About the real going of the Battle of the Atlantic let me suggest the excellent Clay Blair's book Hitler's U boat War. It's a very serious study and an amazing one for the usual reader who is usually accostumed to propaganda themes.
Greetings
EC
take it easy, please, war is over.
I beg your pardon for my modest English. I'll try to be more understable.
When you begin the project of a submarine boat the first item to consider is the floating reserve.
A boat whose task is to fight afloat and to dive just to avoid the enemy reaction has got an high floating reserve (35%)
a boat which must sail most of her operative life under the sea level had got a low reserve (15%).
The first one (a VII or a IX type boat, just to do an example) is able to sail well on the surface and to cover at a reasonable speed with almost any time the long transfer voyages between her station and an enemy convoy just sighted by air recon or by cryptology analisys.
The second one (a XXI in our debate) is a poor boat surfaced and with the often very rought Atlantic waves would sail like a pig.
In theory a VII U Boote could do 16 knots as its best surface speed, actually it was not more than 12 (any machinery at top speed has got a very short life between two refits and may face breakdowns; top speed is used only when it mattered).
A XXI boat had, by the book, a 15,6 surfaced top speed, actually 12, as a consequence of her streamlined hull, ideal for underwater speed but havoc surfaced, she could do less than 10 rolling like hell (and we must consider the strain for the crew too).
Moral: the XXI was the necessary evolution of the submarine, as to go underwater was the only way to survive in front of the by now very efficient and deadly Allied ASW doctrine. The classic submarine of the First and Second World War was a dead man walking in 1943.
The real problem, anyway, was not to survive, but to decimate the convoys, like during the former happy times. Type XXI could survive after a single attack, but had quite more problems to catch the enemy convoys than the VII as it was slower and sailed worste.
It was much more difficoult to led mass attacks with the XXIs for the same reasons.
The XXI, once would be able to find (almost alone) hes target (a convoy, of course, not a slow straggler or a lone (slow again) freighter, statistical not existent in the upper Atlantic in 1943-1945 and which were at the mercy of any surfaced submarine, out fashioned too) could do a surface brilliant lone attack (maybe lauching in a single gulp all his 6 bow torpedoes with circling courses ect. statisic were against this system since 1942; as Adm. Andrew B. Cunningham, himself an excellent sailor, wrote in his memories "Ther's always more sea than ships") and, then, escape at hight speed avoiding enemy tetailation, but nothing more.
An hour of full speed underwater is enough to drain any batteries. At best you can do 20 minutes, than only creep. The theroical capacity is always quite under the real terms (batteries are capricious, today too; the electrical system suck power as vampires; they are fragile ect.) and any commander is quite prudent. Don't forget that it's impossible, in a cold sea like the Atlantic ocean, to stay underwater without the machinery going. This is a difficoult exercise in warm seas, but it's simply impossible in the cold ones, it's a matter of idrography and phisics.
The XXI was a natural evolution of submarine warfare; it was not the key for a renewed succesful strategy against the 1943-1945 convoys able to achieve the previous 1940-1943 successes.
During the last part of the war (1943-1945) a VII boat (or, better a wolfpack) could attack a convoy, but had a very hight chance to be sunk getting little in change.
A XXI boat had more problem than the VII (or even IX) to attack a convoy; she could do it almost alone (a copule at best); she could hope in a legitimate way to get a kill or, maybe, two; she could avoid enemy reaction almost in a sure way (a little optimistic, but we can concede it, for the first times at least); but could not do anything more as the convoy would be soon beyond her range and this little war had not a single chance to win the tonnage war gained by USA since the beginning of 1943.
About the real going of the Battle of the Atlantic let me suggest the excellent Clay Blair's book Hitler's U boat War. It's a very serious study and an amazing one for the usual reader who is usually accostumed to propaganda themes.
Greetings
EC
Ciàpla adasi, stà léger.
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Enrico Cernuschi
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Enrico, thank you sir for taking the time out to post an informative piece.
I will add my opinion that since the surface performance of a German submarine had by 1943 become its biggest liability, the floating reserve advantage of the Vll's was irrelevant. Not only was it irrelevant but it was a liability. This isn't an opinion but a fact of military history.
I respectfully disagree that the "real problem" was not to survive. First the submarine has to make it out into the open waters of the North Atlantic, something that was getting more and more difficult from '42 onward. Once there, again, survival against the air threat became more and more important with the emergence of the escort carrier.
Its also important to credit, as you fail to do, that "all" the abilities of the type XXl, minus surface stability, were improved from previous classes. XXl was much quieter underwater and far more protected from ASDIC,, she had an improved targeting system, an improved torpedo reloading system, better torpedoes, a low profile schnorkel with an effective radar detector..... I take the position that the ability to launch 18 FAT or LUT torpedoes against a convoy, by one submarine, in 20 mins was a very real and deadly threat.
Theres no sense arguing about the effectiveness of wolf pack attacks. The simple fact was that in the last few years of the war it wasn't real healthy for a submarine to transmit on their radios for any reason. Should a submarine have to do so, say to transmit convoy info, the XXl was in a far better position to do so, and the survive after, then the more conventional submarine types.
Your "vastness of the Atlantic" statement doesn't really reflect reality either. Submarine patrols keyed on established shipping routes, and in the early war, in-shore choke points. Actually starting in '43 on the XXl would have been far better suited for such littoral operations. For instance the 2'nd "Happy days" off the American coastline. A XXl patroling underwater, with a passive convoy detection ability of 50 miles, was a a faily effecient patrol warship. Other convoy detection assets would still be used anyways. As would other more conventional submarines.
The survivability of the XXl, after an attack, cant only be credited due to its high underwater speed. The fact is the higher the underwater maneuverability of a submarine, and the longer it can do so, the harder it is for a surface warship to successfully attack her. The higher the speed of destroyer results in a lesser ability to locate and destroy a underwater submarine. The destroyers locational equipment becomes less functional the higher the speed. Most of all against a XXl which was extremely silent to begin with and capable of extreme depths.
The XXl was quite safe from her enemies even in '45, let alone how she would have been in 1942. And the problems with her construction were mostly associated with the general breakdown of German production in the late war. Had she been built in '42 there would have been far less production issues.
So again.........those 120 XXl's in '42/'43.
I will add my opinion that since the surface performance of a German submarine had by 1943 become its biggest liability, the floating reserve advantage of the Vll's was irrelevant. Not only was it irrelevant but it was a liability. This isn't an opinion but a fact of military history.
I respectfully disagree that the "real problem" was not to survive. First the submarine has to make it out into the open waters of the North Atlantic, something that was getting more and more difficult from '42 onward. Once there, again, survival against the air threat became more and more important with the emergence of the escort carrier.
Its also important to credit, as you fail to do, that "all" the abilities of the type XXl, minus surface stability, were improved from previous classes. XXl was much quieter underwater and far more protected from ASDIC,, she had an improved targeting system, an improved torpedo reloading system, better torpedoes, a low profile schnorkel with an effective radar detector..... I take the position that the ability to launch 18 FAT or LUT torpedoes against a convoy, by one submarine, in 20 mins was a very real and deadly threat.
Theres no sense arguing about the effectiveness of wolf pack attacks. The simple fact was that in the last few years of the war it wasn't real healthy for a submarine to transmit on their radios for any reason. Should a submarine have to do so, say to transmit convoy info, the XXl was in a far better position to do so, and the survive after, then the more conventional submarine types.
Your "vastness of the Atlantic" statement doesn't really reflect reality either. Submarine patrols keyed on established shipping routes, and in the early war, in-shore choke points. Actually starting in '43 on the XXl would have been far better suited for such littoral operations. For instance the 2'nd "Happy days" off the American coastline. A XXl patroling underwater, with a passive convoy detection ability of 50 miles, was a a faily effecient patrol warship. Other convoy detection assets would still be used anyways. As would other more conventional submarines.
The survivability of the XXl, after an attack, cant only be credited due to its high underwater speed. The fact is the higher the underwater maneuverability of a submarine, and the longer it can do so, the harder it is for a surface warship to successfully attack her. The higher the speed of destroyer results in a lesser ability to locate and destroy a underwater submarine. The destroyers locational equipment becomes less functional the higher the speed. Most of all against a XXl which was extremely silent to begin with and capable of extreme depths.
The XXl was quite safe from her enemies even in '45, let alone how she would have been in 1942. And the problems with her construction were mostly associated with the general breakdown of German production in the late war. Had she been built in '42 there would have been far less production issues.
So again.........those 120 XXl's in '42/'43.
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sid guttridge
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Hi Rich,
I think that Enrico's point that the real problem was not merely to survive remains very relevant. Submarines are an offensive weapon. Any number of Type XXI's might be surviving in the Atlantic, but if they were not delivering sufficient effective attacks then they could not be "war winners". I would suggest that this latter area of their offensive potential, which you touched on at the end of your paragraph 4, is where discussion should be focused. Could a Type XXI deliver the same threat as two, three or however many Type VIIs?
Other factors are also relevant. For example, Type XXIs took up many more man hours to construct than Type VIIs. More easily produced Type VIIs were still causing massive losses into 1943, so there would have to be foreknowledge of future Allied countermeasures successes to justify a much earlier switch to Type XXIs, which could only be done at the cost of Type VII production..
The Type XXI was a weapons system, rather than a single weapon and many different areas of development had to come together some three or four years early to deliver 120 operational Type XXIs in 1942-43. You mention several: "improved targetting system, an improved torpedo loading system, better torpedoes, a low-profile schnorkel with an effective radar detector....." etc., etc.. Were all of these really potentially deployable by 1942-43?
Cheers,
Sid.
I think that Enrico's point that the real problem was not merely to survive remains very relevant. Submarines are an offensive weapon. Any number of Type XXI's might be surviving in the Atlantic, but if they were not delivering sufficient effective attacks then they could not be "war winners". I would suggest that this latter area of their offensive potential, which you touched on at the end of your paragraph 4, is where discussion should be focused. Could a Type XXI deliver the same threat as two, three or however many Type VIIs?
Other factors are also relevant. For example, Type XXIs took up many more man hours to construct than Type VIIs. More easily produced Type VIIs were still causing massive losses into 1943, so there would have to be foreknowledge of future Allied countermeasures successes to justify a much earlier switch to Type XXIs, which could only be done at the cost of Type VII production..
The Type XXI was a weapons system, rather than a single weapon and many different areas of development had to come together some three or four years early to deliver 120 operational Type XXIs in 1942-43. You mention several: "improved targetting system, an improved torpedo loading system, better torpedoes, a low-profile schnorkel with an effective radar detector....." etc., etc.. Were all of these really potentially deployable by 1942-43?
Cheers,
Sid.
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sid guttridge
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Hi Rich,
I have just been looking up a few facts.
Apparently a Type VIIC took 215,000 man hours to produce by traditional shipbuilding methods in Autumn 1943, whereas Type XXIs were taking 332,000 man hours by December 1944 using production line methods. This was projected to fall further. Thus, as a rough measure, one could produce about three Type VIIs for two Type XXIs.
To introduce the production line method took from August 1943, when it was first suggested, until July 1944, when the first such deliveries, on a limited scale, began at all three yards producing Type XXIs.
If production had not been limited by Western Allied aerial operations, the loss of shipyards to the Russians, etc., it seems likely that the 120th Type XXI would have been delivered in about early February 1945 - i.e. about 8 months after the first boat was delivered.
As it was, only one Type XXI was made operational in May 1945, and even then it was rushed prematurely into service. Assuming the same time scale as for deliveries, and no losses from any cause, it would take another 8 or so months to commission 120 Type XXIs.
Thus I would suggest that it would require a lead time of about 11 months + 8 months + 3 months + 8 months = 30 months to get 120 Type XXIs in service.
Assuming that the facilities of 1943-45 were available in earlier years, (which I doubt) I would suggest that to get 120 Type XXIs operational for, say, mid 1943, would require production preparations to begin at about the end of 1940. Development, of course, would have to start rather earlier.
Cheers,
Sid.
P.S. The source for the above is "The U-Boat" by Eberhard Rossler, London, 1981.
I have just been looking up a few facts.
Apparently a Type VIIC took 215,000 man hours to produce by traditional shipbuilding methods in Autumn 1943, whereas Type XXIs were taking 332,000 man hours by December 1944 using production line methods. This was projected to fall further. Thus, as a rough measure, one could produce about three Type VIIs for two Type XXIs.
To introduce the production line method took from August 1943, when it was first suggested, until July 1944, when the first such deliveries, on a limited scale, began at all three yards producing Type XXIs.
If production had not been limited by Western Allied aerial operations, the loss of shipyards to the Russians, etc., it seems likely that the 120th Type XXI would have been delivered in about early February 1945 - i.e. about 8 months after the first boat was delivered.
As it was, only one Type XXI was made operational in May 1945, and even then it was rushed prematurely into service. Assuming the same time scale as for deliveries, and no losses from any cause, it would take another 8 or so months to commission 120 Type XXIs.
Thus I would suggest that it would require a lead time of about 11 months + 8 months + 3 months + 8 months = 30 months to get 120 Type XXIs in service.
Assuming that the facilities of 1943-45 were available in earlier years, (which I doubt) I would suggest that to get 120 Type XXIs operational for, say, mid 1943, would require production preparations to begin at about the end of 1940. Development, of course, would have to start rather earlier.
Cheers,
Sid.
P.S. The source for the above is "The U-Boat" by Eberhard Rossler, London, 1981.
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Enrico Cernuschi
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According the German memories the technology for the XXI boats was available in 1938. The Italian sources of the time about the German new batteries agree; ther's a report by the then Captain De Courten (the Italian navy attaché in berlin), dated 1937, which confirm this detail (the improved batteries were the hard core of the design).
The Germans had tried to develop the pure submarine concept with the Walter turbine (but the prototype V 80, a not military design with a formidable bubbles track behind him, wa snot rrady before 1940).
It was only the Walter system delayed development which induced, in late 1942, to conceive the project of the XXI, not a true underwater submarine, but a submersible able to longer and more brilliant performances under the sea.
The true submarine (not by the Walter turbine, but with nuclear power) was the key; the elektroboote was a stop gap solution.
A confirmation? Unca Stalin's many (more than 120 Whiskey and Zulu in 1953) elektroboote did not grant the Soviet Navy, form her Artic bases, a trump card in the Fifties. The real problem were the atomic subs of the Sixties and, above all, the Seventies and the Eighties until the collapse of the wall. They were noiser than the by now classic elektroboote, but they had the range and the speed to gain an attack position many times against a convoy (*).
The elektroboote (but only the tested ones of the Fifties, not the too much hurry XXI and XXIII) was an useful tool, but not a war winner. The same necessity to develop AIP since the Sixties is a further confirmation that some hours more with better batteries was not enough.
Bye
EC
(*) I yet said that there was too, since the Seventies, quite a smaller number of possible targets as the freighters were now few and bigger. About the stocks in Europe to led a war against USSR it's simply wishful thinking. Think only at the resources spent in Iraq in 1991 or in 2003 or against Yugoslavia in 1999. The waste of ammuniotion is always fantastic.
The Germans had tried to develop the pure submarine concept with the Walter turbine (but the prototype V 80, a not military design with a formidable bubbles track behind him, wa snot rrady before 1940).
It was only the Walter system delayed development which induced, in late 1942, to conceive the project of the XXI, not a true underwater submarine, but a submersible able to longer and more brilliant performances under the sea.
The true submarine (not by the Walter turbine, but with nuclear power) was the key; the elektroboote was a stop gap solution.
A confirmation? Unca Stalin's many (more than 120 Whiskey and Zulu in 1953) elektroboote did not grant the Soviet Navy, form her Artic bases, a trump card in the Fifties. The real problem were the atomic subs of the Sixties and, above all, the Seventies and the Eighties until the collapse of the wall. They were noiser than the by now classic elektroboote, but they had the range and the speed to gain an attack position many times against a convoy (*).
The elektroboote (but only the tested ones of the Fifties, not the too much hurry XXI and XXIII) was an useful tool, but not a war winner. The same necessity to develop AIP since the Sixties is a further confirmation that some hours more with better batteries was not enough.
Bye
EC
(*) I yet said that there was too, since the Seventies, quite a smaller number of possible targets as the freighters were now few and bigger. About the stocks in Europe to led a war against USSR it's simply wishful thinking. Think only at the resources spent in Iraq in 1991 or in 2003 or against Yugoslavia in 1999. The waste of ammuniotion is always fantastic.
Ciàpla adasi, stà léger.
Submarines were never a "trump card". Probably the closest they came to being so were in the first few years of WW-ll, when they did come close to strangling England, a country completly dependant on the sea. Talking about "trump cards in the 50's" is irrelevant, there was no war and it isnt the subject matter.
Really it all comes down to Hitler expecting a short war. No arm of the German armed forces was prepared for a long war when hostilities commenced, especially the Navy! Of even bigger importance, and greater stupidity, was the emphasis on resources for surface raiders. The biggest waste being the BBs. It all turned out into the U-boat arm not getting the resources it needed for development of new boats,and, construction of true "blue water" boats. Of equal importance was a lack of a naval air arm. The Allies are lucky Donitz was not running Germany, tho even he made a few bad mistakes.
What makes this unforgivable if thet the Germans enterred the war with one proven weapon of strategic importance. And that was the submarine! If they had enterred the war with proven torpedoes they would have deeply hurt the British navy. As it was they almost brought England to her knees with convoy attacks. Why didnt they?
Donitz envisioned a large U-boat force of medium sized boats operating with refined WW-l tactics. He correctly estimated that early sonar wasnt that big a threat to a deep diving submarine, what he underestimated was radar. So as brilliant as the man was he to made fatal mistakes. I agree, Germanys failure to anticipate the evolution of submarine warfare cost her dearly.
Now as much as Ive read about the XXls I cant find anything about them being such lousy surface ships. Not that it matters, they would be spending most of their time underwater anyways. The traditional methods of detecting convoys, radio'ing their course, and deploying U-boats in the way, would still be effective. More so in that the XXl would be better suited for survival after using her radio.
Evertying I read supports the conclusion that there were no real technological reasons why they couldnt have been built earlier. Obviolsly some of her refinements were reactions to Allied technologys, like refined radar detection, and couldnt have been available at first.
I have problems comparing "man hours" of 1943 with that of '44. German production in Dec '44 was starting to be squeezed pretty bad and was shortly going to come apart at the seams. Dec. 1944 was certainly not the time to be doing a revolutionary building process of a revolutionary design. But is there really an argument you'd be better off building two type Vll's instead of one XXl at that time?
Instead imagine numbers of XXl's becoming available at the time Donitz originally pulled his fleet in the for first time. This is the crux of my argument, not 1945.
Really it all comes down to Hitler expecting a short war. No arm of the German armed forces was prepared for a long war when hostilities commenced, especially the Navy! Of even bigger importance, and greater stupidity, was the emphasis on resources for surface raiders. The biggest waste being the BBs. It all turned out into the U-boat arm not getting the resources it needed for development of new boats,and, construction of true "blue water" boats. Of equal importance was a lack of a naval air arm. The Allies are lucky Donitz was not running Germany, tho even he made a few bad mistakes.
What makes this unforgivable if thet the Germans enterred the war with one proven weapon of strategic importance. And that was the submarine! If they had enterred the war with proven torpedoes they would have deeply hurt the British navy. As it was they almost brought England to her knees with convoy attacks. Why didnt they?
Donitz envisioned a large U-boat force of medium sized boats operating with refined WW-l tactics. He correctly estimated that early sonar wasnt that big a threat to a deep diving submarine, what he underestimated was radar. So as brilliant as the man was he to made fatal mistakes. I agree, Germanys failure to anticipate the evolution of submarine warfare cost her dearly.
Now as much as Ive read about the XXls I cant find anything about them being such lousy surface ships. Not that it matters, they would be spending most of their time underwater anyways. The traditional methods of detecting convoys, radio'ing their course, and deploying U-boats in the way, would still be effective. More so in that the XXl would be better suited for survival after using her radio.
Evertying I read supports the conclusion that there were no real technological reasons why they couldnt have been built earlier. Obviolsly some of her refinements were reactions to Allied technologys, like refined radar detection, and couldnt have been available at first.
I have problems comparing "man hours" of 1943 with that of '44. German production in Dec '44 was starting to be squeezed pretty bad and was shortly going to come apart at the seams. Dec. 1944 was certainly not the time to be doing a revolutionary building process of a revolutionary design. But is there really an argument you'd be better off building two type Vll's instead of one XXl at that time?
Instead imagine numbers of XXl's becoming available at the time Donitz originally pulled his fleet in the for first time. This is the crux of my argument, not 1945.
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Enrico Cernuschi
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sid guttridge
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Hi Rich,
The manhours argument is prey to many variables. Before December 1944 the manhours taken to build Type XXIs were higher, and afterwards they were lower. It also varied from yard to yard. I picked December 1944 because that was when production reached its highest volume. Thereafter Allied bombing clearly made an impact on output.
That said, as planned, it was never expected that a Type XXI would take as few manhours as a Type VII. They also absorbed significantly more materials than a Type VII.
As I also understand it, the original proposition was not whether it would be better building two Type VIIs than one Type XXI in late 1944, when the Type VII was already proven impotent, but whether it would have been worth building large numbers of unproven Type XXIs at the expense of Type VII production in 1941-43, when the Type VII was still a highly successful weapon. This is a more questionable decision to have to make without the benefit of our current hindsight.
I would still go back to two of my original general points. One could take many a weapon out of its historical context and deposit it in an earlier era where it would be a war winner. This is especially true in the modern era when technological developments occur so rapidly. Furthermore, with hindsight one can almost always see shortcuts that would have speeded their development and blind alleys that could have been avoided.
There is also the point that once one introduces one new historical variable into the equation the trajectory of every other historcal factor is affected. One cannot take it for granted that the Allies would have continued on the course they did, as if there was no Type XXI programme.
Cheers,
Sid.
The manhours argument is prey to many variables. Before December 1944 the manhours taken to build Type XXIs were higher, and afterwards they were lower. It also varied from yard to yard. I picked December 1944 because that was when production reached its highest volume. Thereafter Allied bombing clearly made an impact on output.
That said, as planned, it was never expected that a Type XXI would take as few manhours as a Type VII. They also absorbed significantly more materials than a Type VII.
As I also understand it, the original proposition was not whether it would be better building two Type VIIs than one Type XXI in late 1944, when the Type VII was already proven impotent, but whether it would have been worth building large numbers of unproven Type XXIs at the expense of Type VII production in 1941-43, when the Type VII was still a highly successful weapon. This is a more questionable decision to have to make without the benefit of our current hindsight.
I would still go back to two of my original general points. One could take many a weapon out of its historical context and deposit it in an earlier era where it would be a war winner. This is especially true in the modern era when technological developments occur so rapidly. Furthermore, with hindsight one can almost always see shortcuts that would have speeded their development and blind alleys that could have been avoided.
There is also the point that once one introduces one new historical variable into the equation the trajectory of every other historcal factor is affected. One cannot take it for granted that the Allies would have continued on the course they did, as if there was no Type XXI programme.
Cheers,
Sid.
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Enrico Cernuschi
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