Type XXI: A Game changer?

[Gargamel]

I am currently playing a late war career using a type XXI. After my first patrol got completed, I was astounded. This thing is amazing. 20 Knots submerged? 6 forward tubes? Snorkel? A small pack of these, like 4, would have decimated, or even completely destroyed an early war convoy. But I got to thinking, you really can't play the what-if game. But I kept thinking that if the Germans had the XXI's earlier in the war, the outcome may have been much different.

Then I bought U-boat war today (via subsim link!), and I quote Blair, from the forward:

Prominent experts gushed that the Type XXI represented a giant leap in submarine technology, bringing mankind very close to a "true submersible." Some naval historians asserted that if the Germans had produced the Type XXI submarine one year earlier they almost certainly could have won the "Battle of the Atlantic" and thereby indefinitely delayed Overlord

How much affect do you think these super boats would have had on the war if they had them even earlier than Blair proposes? Assuming of course the obvious faults found in the XXI were either properly designed to start with or fixed soon after. How much would this sub have mattered without the late war pressure on it's production?

[CCIP]

Historians hate what-ifs for a reason. You can argue almost anything by changing the facts/circumstances, when in fact nothing can exist without them...

My own view is that the XXI, even if it came around earlier, would still be too little too late. Even by 1942 the Germans were already in fact doomed, if only in the most crucial theater of war - the Eastern Front, which would have been impossible to stop with submarines.

As far as the XXI itself, its earlier introduction would have just accelerated the development of countermeasures, of which the allies had many. While it certainly would be a much bigger challenge, it was still fundamentally susceptible to many of the weapons the allies already had in numbers - hedgehogs, squids, downward-sweeping sonar, MAD, sonobuoys, FIDO. I think there's no question there would be a serious shock - but that shock would be the kind that, let's say, the success of Operation Drumbeat was, not by any means the kind that Hiroshima and Nagasaki were. It was a weapon with obvious and counterable weaknesses. On top of that, Blair quite correctly identified many flaws, teething troubles and design failures it had. The net result would be that they would run wild for about half a year, and then the allies would catch up. They already had all the technology needed to kill these boats, it was just a matter of developing it further.

[Sledgehammer427]

Originally Posted by CCIP

My own view is that the XXI, even if it came around earlier, would still be too little too late. Even by 1942 the Germans were already in fact doomed, if only in the most crucial theater of war - the Eastern Front, which would have been impossible to stop with submarines.

This.

I do like the what if's of the XXI. but what happened, happened.

[Missing Name]

I think it might have made a significant difference, but still wouldn't be the whole solution.

Similarly, the Japanese had high underwater maneuverability subs in the works, the I-201 class. There are obvious design differences between the XXI and the 201, however. http://en.wikipedia.org/wiki/I-201_class_submarine

[Tonga]

@ CCIP:
Very well said!

Personally, I think the main reason for why the type XXI is still somewhat mystified today is just the fact that it was indeed a great step forward compared to the older boats. One has to keep in mind that the basic concept of the older boats like the types VII and IX still originated from WWI, which meant that they were rather surface vessels with diving capabilities than real permanently submerged vessels. With that said, we can surely say the type XXI was at least a conceptual improvement, which of course then suffered from several other flaws.
In a simulation like SH3/4/5 we are able to experience some of these differences between the old types and the type XXI and have the possibility to directly compare them. However one has to be enough of a realist to see that naval warfare alone can not decide the outcome of a war of that dimension (huge army operations, large scale airborne operations etc.). The Germans probably would have been able to delay Operation Overlord, yes, but they would not have been able to actually prevent the Allies from executing this operation whatsoever. Losses on the Eastern Front were too high to effectively mobilize forces for the late-war Western Front. In the end, it always comes down to army forces trading bullets, grenades and other nasty stuff in cities, and that's just where naval forces are very unlikely to be found at all. So - surely not a real game changer, but considering the fact that these boats were able to save some civilian lives during the mass exodus on the Eastern Front, at least they somehow served a better purpose in the end.

Leaving aside the flaws in design (hydraulic components outside the pressure hull and so impossible to repair submerged) and workmanship (hull sections from different builders not fitting, poor quality welding etc.) cited by Blair in Hitler's U-Boat War, Type XXI fans tend to be so enamoured by the technology they give no thought to the difficulties involved in their effective operation.

Diesel-electric boats are still submersibles rather than true submarines. The Type XXI sprint speed was certainly impressive (post-war tests indicated more 17-18 knots rather than 20 but SH3 is a U-Boat sim after all) but its sustained maximum cruising speed was much lower. This made intercepting convoys on the high seas a huge problem.

How big? Try intercepting an 8-knot convoy on the surface with a 12-knot Type II. That small 4-knot speed advantage means that in many cases you will be unable to achieve an effective firing position. Without the sustained high-speed transit capabilities of a nuclear boat, convoy operations become dependant on the luck of the draw and favorable geometry. Type XXI's only had a couple of hours at 12-knots and the vast majority of interceptions would have been conducted by passive sonar without the benefit of signal processors, waterfall displays and high-speed computers. The problems were technologically unsolvable in 1944-45.

Even at the end of the war the problem was less attacking the convoys than it was finding them. Patrol lines of Type XXI's could not talk to each other or BdU without exposing their masts and transmitting on the HF bands. Keeping a plot of HFDF intercepts would allow convoys to be routed around lines of Type XXI's as they were routed around the VII's and IX's during the convoy battles of 1941-43. The big difference being that the transit speed of the XXI's was much less and so concentration against any convoy would be more difficult. To be sure a single XXI could make a successful slashing attack on a convoy but its chances of a re-attack on the same convoy would be minimal in most cases.

If you want to see where Type XXI's may have been effective, look at the Soviet submarine doctrine during the Cold War. The nuc boats operated on the high seas but the diesel boats were confined to strategic choke points and shallows where the targets could come to them. This solved much of the locating and interception problem but also put the boats where ASW assets were strongest. This is a good model to use though, since Soviet boats before the Kilo's were largely based on the Type XXI design. The Red Banner Fleet also had the priceless advantage of satellite intelligence and and secure SATCOM to minimize exposure of the boats at sea, operational aids unimaginable for the u-boot waffe.

It is perhaps significant that the patrol area for KK Schnee and U-2511's first combat patrol was off New York, where targets could come to him and no BdU control was required. Also if he could survive there and rack up any sinkings it boded well for lesser Type XXI captains functioning in an intense ASW environment. Initially the XXI's would have come as a nasty surprise but the Allies would have adapted and the results would have been exactly the same. One would be wrong to assume that everything would have gone the German's way and that the Allies just would have folded and collapsed in panic or not developed effective counter-measures.

[Jimbuna]

It may have prolonged the war in the Atlantic but not enough to do much more than delay the inevitable invasion of France (Overlord).

The Russians would probably have conquered all of Germany or perhaps the Americans might have tested the first atom bomb on Germany.

There are so many ponderables I prefer to accept what happened in reality.

[SilentSnake]

I think the battle of britain had the biggest effect on german losing the war initially followed by their decision to invade russia. Their resources where so thin and they strongest ally was too far away and losing their war to the USA.

[Missing Name]

The "what if?" factor for the XXI is almost like trying to figure out the Drake equation.

There are just too many factors to figure out.

(The Drake equation is a model for finding intelligent life on other planets and is pretty much a string of random numbers.)
http://en.wikipedia.org/wiki/Drake_equation

[CCIP]

That's like any what-if though!


And if we're talking those, I think out of all the ones related to U-boats, for me the most interesting one has always been nothing to do with technology, but rather "what if Doenitz had the 300 boats he wanted in '39/'40"? That one always seemed far more dangerous to me than anything the XXI could affect...

Britain only reluctantly ceded submarine parity with Germany in the London Naval Treaty as a desperate act of appeasement meant to buy time for her own rearmament schemes.

Does anybody really think they would have sat idly by while German shipyards cranked out a program for 300 boats by 1940?

Producing 300 U-Boats in five years from scratch has a great deal to do with technology (conventional building techniques could not do it and Germany had no experiance at modular shipbuilding), economy (even in Nazi Germany things needed to be bought and paid for and cash was finite) and strategic priorities (the workers and steel needed for a 300-boat building effort would have raped the Army's rearmament program and plans for motorization and panzers let alone what it would have done to the Luftwaffe's wish list).

Of course everyone is forgetting that the Kaiser's U-Boats ultimately failed and made Germany's situation (arguably) worse in 1918 and so selling the land-minded Hitler on a repeat performance from the start was problematic even if the other insurmountable problems acquired solutions.

Everything Hitler wrote about in Mein Kampf pointed East and involved a neutral or even an allied British Empire. A 300-strong fleet of U-Boats would destroy any chances of keeping the peace in the West while contributing nothing to the acquisition of Living Space at the expense of Poland and the Soviet Union that was Nazism's centrepiece agenda.

Without context and balance any "what if" on the Internet quicky degenerates into fantasy worthy of dragons, Middle Earth and magic rings of Power.

Don't forget the "Cloak of Invisibility"...

[OSU]

Originally Posted by Randomizer

Without context and balance any "what if" on the Internet quicky degenerates into fantasy worthy of dragons, Middle Earth and magic rings of Power.

You're forgetting Narnia and "A long time ago, in a galaxy far, far away..."

And yes, I do agree with you on that point. "What-ifs" are always, well, iffy. There are so many things that could have happened. What if the radar operators on Hawaii had been more specific, maybe then the attack on Pearl Harbor might not have been a surprise. We will never know for sure.

[Tessa]

Originally Posted by SilentSnake

I think the battle of britain had the biggest effect on german losing the war initially followed by their decision to invade russia. Their resources where so thin and they strongest ally was too far away and losing their war to the USA.

The German's loss (or rather blunder) is certainly what kept them from ever being able to mount an amphibious invasion of England. When the Luftwaffe was still in charge the bombers were hiting airfields and other vital/strategic targets. One stupid pilots goes off course and unloads his bombs on the city, that mistake doomed Germany for the rest of the war. Had the Germans kept bombing the airfields and radar stations they would have ulitimately overpowered the RAF by brute force of numbers, and the depletion of usable planes. With air supremacy Germany invades England...

Instead Hitler steps in and decrees that civilian targets are more important and that the bombers must be diverted to "break the back of the enemy" rather than its ability to wage war. Once the airfields and planes were safe the RAF stepped up and the rest is history.

For the XXI to have made a real impact would have required increased airpower. By 1943 Germany had ME 262's that were tested and ready to be put into production. Hitler's "military genius" insisted that the 262 be turned into a all in one fighter/interceptor/reconnaisance/bomber aircraft. With the introduction of 262's flying to intercept incoming bombers instead of BF 109's the 8th air force would have been decimated, at the time they had nothing capable of defending against such a fast agile plane. The few that did get into service wrought havoc with just a squadron or two and would take down bombers like a Turkey shoot, by then even if they shot down 12 or 15 there were still 50 more left heading to the target.

Had both weapons been introduced earlier I don't think there's much question it would have had a major impact. It would have prolonged the war at the least and England may have been able to be successfully invaded, but...

Since Hitler kicked out all the best scientist's (or they fled knowing what would happen if they stayed) he handed us all the tools needed to complete the bomb. The Manhattan Project would have still probably proceeded on the same timetable so even if Germany was able to succeed in invading and occupying England and at least create a stalemate on the Eastern front they would have suffered the same fate as Japan, likely even worse since they were even more stubborn. With Japan the Emperor by that time wanted peace and to surrender, Hitler would never have allowed Germany to surrender; he never listened to his best General's/Field Marshall's anyways, the highly decorated Corporal was so much the military genius compared to Rommell or Galland that he didn't need their help or advice on how to use their superior technology

[Axeman3d]

I think it's clear from all this speculation and educated(?) guesswork that we can certainly say the following. Hitler started the war, and is also the primary reason why it was lost as well.

His policies alienated most of the best and brightest, who fled the country and worked for the allies instead.

His 'diplomacy' and foreign policy dropped the German KM in a battle they were not ready for against their worst enemy 5 years before they had planned to.

His short sighted decree that no long term projects would be undertaken hurt German tech advances in the long run. Likewise his decision to design only small aircraft in preference to strategically useful heavy, long range aircraft, and to force the Me262 to be redesigned as a fighter-bomber before he would allow it to be produced. Not smart.

His decision to attack Russia while still engaged on other fronts was spectacularly foolish.

It was his decision to ally with Italy (who his forces had to bail out repeatedly) and Japan (who led him to declare war on the US).

I could go on. In the later years when he took over actual day to day command of the armed forces, it reached the stage that the British cancelled their assassination plans in favour of leaving him in place to cause chaos. They started the war with great equipment, well trained and motivated men, some truly visionary tacticians and massive quantities of self confidence. Unfortunately for them they were led by a racist megalomaniac with delusions of tactical genius.