New U-Boats

The New U-Boats

In the spring of the year 1945 WWII was rapidly coming to an end. Whatever the new weaponry the Germans could invent or even build was useless. Our war machine was absolutely destroyed and the final defeat was unstoppable. Field Marshal Bernard L. Montgomery was pushing his troops to the German ports and shipyards. The British intelligence had found out that we were building submarines, only submarines there. And those were not the submarines which had put Great Britain on its knees in 1941 and 1942 and that after “Black May” had been dominated by the radar and had become hunted instead of hunters. No, these new submarines —of which one hundred were afloat and training in March 1945 and another couple hundred were being finished in the shipyards— were completely different in design and appearance of their elder brothers. What kind of revenge or payback was the German Navy planning? What would be their response to the Allies’ radar?
In May 1943, Großadmiral Karl Dönitz had a meeting in Berlin with scientists and techniques to discuss about the extraordinary efficacy of the anti-submarine methods of the Allies. Dönitz told them the hard truth. The only thing the radar —that little thing which made visible the invisible— could do was helping the Allies to find and later destroy the German U-boats at all. The radar was indeed, the most favourable thing on the Allies’ side.
_ Give me some protection here! —Dönitz shouted. The techniques made an effort and gave the chief the help he needed. They found out about how the radar operated and its wavelength. But it could only tell the Germans that we could be found, so we dive and hide.
But the U-boats had lost all their effectiveness. They were obliged to submerge to escape from the total destruction. There, beneath the water they were slow, blind and awkward. Theorically, their electric engines, powered by the batteries could make seven knots… but only for an hour, because after that, the batteries lost power. And in reality, the shape of the submarines gave them a real speed of only five knots and all the commanders never dared to make that speed, because the batteries would have lost power and all the energy would have been gone after an hour. So, they actually made speeds of two, three or very rarely, four knots and therefore, they were unable to follow the convoys, unless the convoys sailed right towards them, because the convoys had to adapt to the slowest vessels’ speed. Some convoys had a maximal speed of seven knots.
It could sound weird, but all the submarines built to that point had a very inadequate name: it was a vessel built to sail on the surface and only dive in case of danger, and that was precisely what was happening now.
Naturally, this events made the future look dark. Dönitz and his officers did not get any surprise for “Black May”, when forty three U-boats were sunk all at once. In the same way as we were sending more and more submarines to the Atlantic, the enemy took more and more measures to destroy them.
On late November 1942, the OKM send three naval builders to Paris for a meeting with Dönitz.
_ We must not take on account only our successes —said the commander of the U-boats—. Take a look on this list of our losses: In 1940 we lost twenty four submarines, thirty three in 1941. In the first half of 1942 the losses were relatively short if we consider that we sent a lot of boats to the operation zones. But look how the graphics start rising since then. —The ciphers were as follows: July 1942, nine U-boats; August, twelve; September, nine; October, fourteen and fourteen more in November—. We suffered the 80% of those losses in the surface. Our submarines are not submarines no more, you know that as well as I do. But they must be in the future. I am very inpatient for you to finish the construction of the new Walter submarines.
_ What would you think, sir, if we build a much larger submarine, with more powerful batteries and an aerodynamic line, preserving its surface qualities? —inquired one of the builders.
_ Of course it would be great. But the main thing here is that the submarines must not come out to the surface often and they must have a high speed beneath the water, so they can operate efficiently.
_ We are going to start preparing the designs immediately.
_ When can I have them?
_ Spring 1943, sir.
When the first designs were presented to Dönitz in June 1943, unperfected and unfinished, Dönitz’s fears had become true: the submarine warfare had been a failure and the Allies were winning.
That is why the development of the new Type XXI —as it was called— was urgent. They would have three times more batteries than the other submarines, the armoured bridge would reduce as much as necessary and the hull would be aerodynamic. It would be able to make seventeen knots under water! It would be the first submarine to sail under the water…
But those were only designs on paper. Nothing had been done. The builders said that the first U-boats would be finished in a year and a half: in late 1944. What would happen meanwhile?
Dönitz, chief commander of the OKM had to make a very difficult decision. Should he give up with the submarine warfare, now that it was losing efficacy more and more? The horrible losses had made him retreat his U-boats from the most dangerous zones, like the middle of the Atlantic. They had to be withdrawn to safer, but less important zones of the Atlantic.
Dönitz was tormented day and night treating to solve things and relief the luck of his men. He could not stay calmed when he was sending them to a very unfavourable struggle; he was very worried about every single U-boat and his staff knew that nothing made the Admiral happier than the news when a submarine which had not reported to the headquarters for several days sent a message from the Atlantic. Despite of that, he had to send them, he could not keep them for better times: every single sinking of an enemy ship had big importance, even if it couldn’t be as decisive as in the past days. But with it, the Allies could not breath and were forced to reinforce their defences, thousand of aeroplanes had to be used to search submarines, otherwise they would have been used to bombard the Reich. And there was another reason, if he kept his submarines, to rust in ports, the crews would lose their experience and could not be used for the planned revenge that Dönitz and the officers were planning with the Type XXI.
They were not idle elsewhere either meanwhile the Type XXI was ready. There were built radars for the submarines to detect when they had been detected. The “Schnorkel” was developed and put onto the U-boats. This invent gave the Diesel engines the air they needed to run. This aerial-mast provided the necessary air for the batteries to recharge without emerging.
Beside, the old fashioned deck-guns were replaced by anti-aircraft guns. In case the submarine could not dive, the AA weaponry would be used. There were several British aircraft shot down by U-boats, although it happened more often that the U-boats were the hunted ones.
Kapitänleutnant Hartmann was the first to sail in an anti-aircraft submarine, but had to fight with a lot of British fighter-bombers and the boat was severely damaged. All the men at the bridge were killed including the commander and all the officers. The ship’s medic had to take her to port. But when they reached port, immediately, reserve-officers got on board the ship and replaced their fallen comrades. It shows how the morale of the Navy was always high, even in the times of horrendous losses.
Meanwhile, many German shipyards were been adapted for the Type XXI. Herr Speer, minister responsible for this programme promised that the first submarines were going to be ready in May 1944; mass production will start on August or September, and from that point would be ready ten a month, then fifteen and twenty at last. But the Allied bombings delayed the programme.
In early 1945, the Allies were prepared to strike Germany from the South, East and West. The ports in France had to be abandoned and the ships were withdrawn to German, Danish and Norwegian ports. The training divisions had to abandon their training places in the Baltic one by one: Pillau, Danzig, Gotenhafen… But despite of that, they went on with the trainings with the new vessels —now that they were launched in big quantities—, hoping to fight until the last moments.
In the last days of April 1945, days before the unconditional surrender, U-2511 sailed from Bergen, Norway. She went away from her sisters and gained speed. The big moment had come. For the first time, a new German submarine, the Type XXI would face the enemy. The men on board were already used to her and knew that they could trust her to sail on the surface or submerged. Within days she would fight the enemy and show that all the expectations on her were right.
U-2511 had and uncertain landscape before her.
Korvettenkapitän Schnee, the commander, was an U-boat veteran. He had been in seventeen battles and sunk 200.000 tons of shipping. Since early 1943 he had worked for the Naval Construction Commission and had seen carefully how the type XXI was developed. Fragattenkapitän Suhren companied him as chief of engineers in U-2511. Very few knew the submarine as these two men. That is why Dönitz ordered the two high-ranking officers into the mission, even if it was very unusual. They were the most adequate men to drive her through any danger and come back safely with a lot of knowledge and new lessons.
When the escort ships abandoned her, Schnee ordered to submerge. He did not feel safe on the surface and he wanted to sneak into the Atlantic under the sea and with moderated speed.
A few days later, the sailor in the hydrophone announced propellers’ noises. Everybody waited, full with anxiety.
Schnee ordered periscope-depth and discovered: a large column of fishing boats and trackers; submarine hunters. Suddenly, a sailor shouted:
_ We have been discovered!!!
The British had advanced towards the German submarine and had located her with the ASDIC. This instrument, invented during WWI could track submerged vessels by sound waves, little tics. However, the ASDIC and the sonar were the only ways to detect a submarine.
The commander rapidly knew that the tracker were approaching the submarine very fast. He knew for self experience that if he was in an old submarine, it would be a life or death situation. He could only have submerged and tried to escape with a speed of five knots by only an hour… Then the bloody “hedgehogs” would come and the damages would be fifteen times worse than with a conventional depth-charges attack.
It had happened that for two years. In 1943 were destroyed two hundred and thirty one submarines; and two hundred and four in 1944. The Allies had recovered control of the sea and the submarines were wild beasts hunted. What would happen next?
Schnee looked his first Lieutenant:
_ We would like to attack them, wouldn’t we?
_ Will you do it, sir?
_ No, kid. We should not waste torpedoes. We have got orders of looking and attacking a big convoy in West Atlantic.
The periscope went down. U-2511 changed its course and dived deeper. And it was not to chance. Now the submarine did not sail blind when submerged. It didn’t need its optic eye (the periscope), because it had now an electronic eye.
This was device “S”, that worked like the British ASDIC. It could detect perfectly all the hulls on the surface, their speeds, course and distance.
In this case, the general image got by the commander was very clear; no more blind sailing. He changed the course to the opposite way from the British and if they came too close he would speed up: eight, twelve, sixteen knots, depending on the situation.
But it was not necessary, the lazy trackers did not want to fight with a tempest coming. The U-2511 with her aerodynamic hull and twenty fathoms deep went on. It did not pass much time when “S” device lost the British and the sounds in the hydrophones decreased until they disappeared.
Four days went by since this incident and the U-2511 never emerged.
Then a second inform from the hydrophones came: propellers’ noises again. Device “S” did not detect anything. The ships must be far. The commander ordered to go from forty fathoms to periscope-depth and then he could see carefully.
He was astonished by what he saw. Before him, on port side, a British cruiser and her escort of three destroyers!!! They were running full-ahead and U-2511 was so good positioned that she just had to move a little to have them perfectly in front of her.
Schnee shouted:
_ All to combat posts!!!
All the sailors prepared for the struggle like if they would have had an old training ship in the Baltic instead of a British combat flotilla! In less than a minute the submarine was again forty fathoms deep and “S” device draw the British’s exact position.
_ If they don’t change course, we can get to a firing position with silence speed.
There was no clue that the British had discovered the submarine’s position. Otherwise, the destroyers would have been already above the ship. But nothing happened.
Now, the U-2511 was very close. The propellers were heard all over the hull, but they had not found the ship yet.
Schnee could have go up a little to use the periscope. The cruiser could have almost been touched: the bridge, the artillery towers, the men in the deck, all that could be seen. Schnee put away the periscope and called all the officers to watch; Suhren, of course, Kapitänleutnat Lüders and other two officers. They all looked each other and shook their heads.
_ This is my seventeenth patrol —Schnee said— and I have never seen a cruiser in front of my tubes before. It had to be now!
_ I can avoid thinking about the past —Suhren said— Can you imagine that we could have got so close, undetected and untouched to a cruiser this way in the old days?
_ They didn’t even hear us.
Effectively, the U-2511 could not be heard. It moved so quietly that the engines could not be heard even inside the submarine. Type XXI has super-silenced engines. And the propeller blades were so very good designed that they could not be heard in silence speed. With this speed of five knots (the same of the old submarines). Except that any commander would have dared to do it. And the U-2511 did not have any problem. These vessels could sail at this speed for days.
If there is heard a strong noise very suddenly, the machines are disconnected and the main engines start running at seventeen knots for a whole hour, fifteen for four hours and twelve for more than ten hours.
All the officers of the U-2511 kept watching the British flotilla. Why didn’t Schnee shoot his torpedoes? The big ship —1.621 tons— had six torpedo tubes in the bow and twenty torpedoes on board. There were six “alive” torpedoes in the tubes and other six queued. However, the commander did not give the order.
Anyway, he was so imprudent to be exactly between the cruiser and a destroyer, twenty fathoms deep. It could have fired very easily to the cruiser and the destroyer at the same time. The “S” device told Schnee very precisely the location of the British. In tests in the Baltic, this device “had” shown to be 100% infallible.
Beside, because of its speed, Type XXI can place exactly beneath the enemy ships, whether it is a convoy or a flotilla. The “S” device will show the exact position of the submarine and the ships. And here, the ASDIC and sonar do not work, because there are many hulls and a lot of noise.
Beside, the Type XXI is equipped with several torpedo types. The normal ones, which need aiming first. The “Lut” or “Fat” which run in a straight-line for a while, then turn and turn again and sail in “zig-zag”. There is the “Zaunkönig” which is an acoustic torpedo that follows the propeller noises of the destroyers. These cannot evade it unless they say full-ahead, because this torpedo is a bit slow. There is also an improved version of the “Zaunkönig” called T11, it follows destroyers and ordinary vessels, is faster and cannot be diverted by noise devices.
Six torpedoes were shot, they ran and fan out and then start zig-zaging, maintaining the convoy’s speed.
All this was been thought by the crew of the U-2511, but the high speed of the flotilla left the submarine behind. They had not been detected, but they did not shoot. Schnee shook his head and retired to his cabin. He wrote all this in the log starting with the date: “May 7th 1945”. Then he read again a message sent by radio:
“Since May 5th, 0800 hors, cease fire. Submarine attacks forbidden. Cease immediately the chase of the enemy. Come back to Norwegian ports at once.
Commander in chief of submarines.”
That is why the U-2511 did not shoot. The war, that since many time ago was offering less and less opportunities of victory had finally come to an end.
For the very same reason, other Type XXI U-boat did not shoot either; U-3008, which departed from Wilhelmshafen. Oberleutnant zur See Manseck did not give the order to shoot the British vessels in front of him.
The U-2511 emerged at the same point it had submerged days earlier. She had sailed underwater all the trip. She headed to Bergen. In that port they found the very same cruiser that had passed before their tubes.
_ God! You don’t know how lucky you were!
Time later, there was a commission sent by the Royal Navy to investigate about the new submarines. They travelled to Kiel to interview Admiral Godt, chief of Staff of the Kriegsmarine. They were told to go to Bergen.
Schnee, Suhren and other officers went on board the British cruiser before some high-ranking officers of His Majesty’s Navy. They were inquired about the performance of the submarine and if they had made contact with the enemy.
_ Yes, I did —responded Schnee.
_ When? What did you find?
_ The very same cruiser we are standing on.
_ That’s impossible, sir —said with pride the captain of the cruiser addressing to the admiral— we did not find any German submarine.
_ I know —answered Schnee, smiling—. I had her at the range of my torpedoes, but you didn’t find out. I did not shoot because it was forbidden to me, due to our capitulation.
All the British officers became excited.
_ Captain Schnee —said the admiral— my officers think that it is impossible that what you say has really happened. Have you got any proofs?
_ Of course I do. The ship’s log. Would you like it to compare with your own log’s details?
A sailor brought the log and the officers compared it. There was no doubt of it. The cruiser had been in the same spot, had the same position and speed than the German submarine’s log said.

In early 1945 there were ready one hundred and twenty of these new submarines of Type XXI and eighty three crews were ready, but only departed U-2511 and U-3008.
Also, Type XXIII submarines were electric, although they weighed only 232 tons; were smaller and had been designed to patrol the coast. Sixty one of these were ready and seven saw action. Five fired two torpedoes and made a hit. Any was sunk.
And there were ready eight Type XVII submarines, of 280 tons, which were the most modern of all. Their fuel “Ingolin” —hydrogen peroxide— made a Walter turbine work and it could make twenty five knots underwater!!!
However, any of these vessels could have altered the outcome of the war, it was too late.

In late May 1945, Fragattenkapitän Heßler, in other time, officer of submarine operations, took seat on board the old "Patria" of Hapag line, before a British commission. He was inquired about many details.
_ In conclusion, captain Heßler, what opportunities would have the new submarines have had against us, according to your opinion?
He thought a bit before answering:
_ Perhaps it would be better if I quote your Prime Minister’s speech on the radio that he gave on May 3rd: “The Germans had prepared a submarines new fleet and new tactics that, even if we had controlled them at last, it could have been like in 1941 and 1942”.
In my opinion —said in a humble way a British officer—, Mr. Churchill was wrong. 1942, in comparison, would have been a kid’s game.

C.D. Bekker, "Kampf und Untergang der Kriegsmarine", Düsseldorf, 1953.

[ 25 July 2002, 06:16 PM: Message edited by: General der Infanterie Friedrich H ]

 

Friedrich :

Excellent material ! thanks for sharing.....

if interested, this site provides some more in-depth coverage of the newer u-booten. Go to technologies and then look for electro-boats.

www.uboat.net

E

 

I told you, Erich, I am going to post the whole book here... If you cannot get it at the book shops, then you will read it here.

 

Well done, Friedrich...

Very nice and interesting piece of history here that I wasn't familiar with...

The experience with these U boote must have left a bitter-sweet taste in the mouth of the Germans...

 

Excellent job Friedrich! The designs of those Type XXI boats were used by the allies and can be seen in today's designs but mostly in the design of the Russian boats. Were the AA guns built into the Tower of the boats? I could swear I have seen some photos of this. It would help in streamlining. Thanks again meine General!

 

No, thanks you all!

PzJgr, Type VII U-boats were equipped with two AA guns, I think twin 37mm and 20mm. The 37s were put instead of the deck 6 inches gun in front of the tower and the 20mm was put in the back of the tower. I might be wrong, but my U-boats book, which have many more technical details is somewhere in this world but my library...

 

blub, blub......oops sorry getting into the water at the moment.......blub / the larger elctro boats had a twin inclosed turret fore and aft with twin 2cm weapons.

The VII and IX milk cows had multiple combinations. Most frequent were the two twin 2cm weapons behind the conning towere and a single 3.7cm quick firing weapon. sometimes this was replaced with the 2cm flakvierling.
Also experimentation with the single 3.7cm behind the conning tower and one also forward along woith the twin 20mm's. Also some later war boats did see the twin 3.7cm at the back of tower for added punch.......blub.....

E

 

Thanks, Erich... That is what I meant!

 

Back from work this morn.....ok Freidrich, I had doen some extensive research into the weapons systems of the Luftwaffe and flak on Kriegsmarine ships some 25to 30 years ago, and haven't open up the archiv for almsot 10 until we did our sturmgruppen web-site 3 years ago. I have quite an amount of material. If any questions I would surely like to answer if anyone would allow me to dig further......

Tschüß

E

 

Thanks, Erich. I know I can count on you, already. And you know that posts like this are adressed to everybody, but a little bit more specially for you, Herr Nachtjagd...führer? How was the whole rank?

 

Thank you for this Herr General--I thoroughly enjoyed reading this--welldone!!

 

I was looking forward a lot for your response, Herr GFM!!!! I love you all like it. It costed me a ball to translate it... (Althought it was a fake rumour) I am now like the man in the avatar...

 

Friedrich:

I hope you don't feel like the pic of Der Führer ! he looks awfully constipated !!!

E

 

It's all the vegetables. Needs more protien

 

I might sing like a woman, or like Farinelli, but I can assure you that I am NOT like Hitler nor like Farinelli!!! I have everything that I must have!!!!

 

Excellent article Friedrich-the only items I might add-on to are the design of the Type XXI was based on a Walter design without the turbine, but with greatly increased battery compartments(I believe approx 3x+ the conventional boats). Also the boats were built in sections(5 including the tower, sticks in my mind) by various firms and then shipped by barge and rail to specific shipyards for final completion. There were serious delays due to poor workmanship/material shortages and the all present Allied bombing campaign. The war realistically would have had extend into '46+ for a significant number of these boats to come online. Time was not on their side.

 

Just imagine 200 XXIs ready in 1942...

 

Don't go so far, Andreas. 200 more normal U-boats (type VIII and IX) in 1942!!!

And just a few months more in 1945, as my article say there were nearly 120 new U-boats ready for action at that time ready to start hunting within a month!

 

The construction of each type XXI sub required an average of 252,500 man hours, and approximately 40,000 production workers were involved in the type XXI program. The new U-boat program tied up not only thousands of workers and 80 per cent of the output of the nation´s entire electrical industry but enormous amounts of steel. The steel for the 170 type XXI submarines ordered would have provided Guderian 5,100 additional tanks.

Hitler,Dönitz and the Baltic Sea by Howard Grier

 

In Mid-December 1943 Dönitz sent Hitler a personal message emphasizing that for the upcoming campaign with the electro-submarines, air reconnaissance was a higher priority than previously. Hitler ordered Göring to increase the output of long-range reconnaissance aircraft for this purpose, but actual production fell far below Dönitz´s needs. If Dönitz had been able to send the Type XXI submarines into the Atlantic, their actually finding targets to attack would have been purely a matter of chance.

Hitler, Dönitz and the Baltic Sea by Howard Grier