Credit: Image copyright www. The Type XXI diesel-electric U-boat of World War 2 was ground-breaking by any measure but it was ultimately doomed by the wartime conditions suffered by Germany heading into The Type XXI series of U-boats developed by the German Navy during World War 2 were revolutionary on many levels and were looked upon by the service as its war-winning design - intended to take back control of the vital Atlantic Theater.
The submarine became the first to operate faster under water than on it and opened the doors to a new chapter in submarine warfare and design - one that would set the roots of submarine work in the Cold War period The Planning The Type XXI was designed specifically for lengthy submerged operation and this centered on high-powered electrical machinery with density cells built directly into the hull. This allowed the boats to produce more power submerged than the vessel could create when on the surface - a decided advantage when compared to the diesel-electric-powered counterparts of the day with their closed-cycle turbine engines.
German Admiral Karl Donitz worked with his staff to plan for the advanced Type XXI to become the new working backbone of the German submarine fleet - such was the challenge laying ahead for the design.
Germany had been at war since September of and the foundation for the new class was laid down in November as Donitz met with engineers in Paris, France with the end-goal of devising an all-new, more powerful attack submarine to supersede the Type IIC class boats in both capability and performance. With this in mind, thought turned to design work being led by Dr. Walter Hellmuth but his submarine was so advanced that it would prove impractical to design, develop and construct under wartime so it was decided that his hull work could be applied to an interim boat design which could immediately be set in motion and be placed in the hands of German submariners in as little time as possible.
Basic Attributes The original tear-drop-shaped hull was mated to a conventional mixed diesel-electric propulsion system and this structure incorporated extensive streamlining. Internally, the pressurized hull utilized figure-eight cross-section and the upper reaches were given a greater span than the lower.
La base sous-marine: the ghostly WW2 u-boat pen
Externally, the dive planes were made retractable and only brought into play when needed. The powerpack lay at the rear of the boat with the torpedo room in the bow. The center-section would be reserved for the command center and crew areas. Aboard would be up to 57 crewmen and such creature comforts as a improved berthing, showers, integrated air recycling and air conditioning systems and freezer storage spaces for food. Sail Ho!
One of the biggest changes to German submarine design in the Type XXI was the streamlining of the sail - gone were the many protrusions and platforms common to submarines of the period and, in its place, was erected a low-profile sail set over midships. All of the usual protrusions periscopes, snorkel, antenna were contained at the top of the sail with the snorkel being of particular note for it utilized a double-tube form with valves in place to allow the scope to be raised above the water line with the boat completely submerged - in turn allowing the boat to maintain its stealthy advantage while still expelling dangerous CO2 gasses as it lay near not at the surface of the water.
The valves also worked to keep seawater from coming into the scope but the danger still lay in the valve shutting unnoticed - as the diesel would continue to operate if left unchecked and potentially kill the crew in the process of drawing on the internal air of the submarine. Instead of the deck guns common to attack boats of the war, the Type XXI would rely on a pair of Anti-Aircraft AA turrets 2 x 20mm were fitted to the forward and aft facings of the conning tower.
Both were remotely-controlled from within the boat, no longer requiring the gunnery crew to be exposed to the elements to fend off aerial attackers the greatest threat to a World War 2 submarine.
No traditional deck gun was fitted per se though the tower was originally intended to carry a 30mm cannon for surface work. Special Systems The boat was given an emergency steering mechanism in its aft-end which acted as insurance should the main steering compartment be compromised in some way. The passive component of the sonar installation was the Gruppenhorchgerat GHG passive sonar which was installed at the keel.
The active component became the advanced "Unterwasser-Ortungsgerat Nibelung" non-line-of-sight system. Armament At the bow was the torpedo room worked in conjunction with the sonar fit as it was to receive targeting data from the sonar room with the data inputted into the new Lageunabhangiger Torpedo.
A semi-automatic hydraulic system was intended to aid the crew in the reloading of the torpedoes - providing a reload time of just 20 minutes to fire three salvos of six torpedoes each.
The older U-boats required about ten minutes just to load a single torpedo! The boat's kill probability was therefore quite high for its time as few vessels if any could react in time to such an attack.
The boat was armed with 6 x mm torpedo tubes, all bow-facing, and carried up to 23 reloads though this total could be reduced to make room for TMC naval mines. The boat had no rear-facing torpedo tubes which was common practice for period submarines.
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Ballpoint Pen. Rollerball Pen. Fountain Pen. Pen Set. Gift Set. Star Wars. Pen Pouch.A submarine pen U-Boot-Bunker in German is a type of submarine base that acts as a bunker to protect submarines from air attack.
The term is generally applied to submarine bases constructed during World War IIparticularly in Germany and its occupied countries, which were also known as U-boat pens after the phrase " U-boat " to refer to German submarines. Among the first forms of protection for submarines were some open-sided shelters with partial wooden foundations that were constructed during World War I.
These structures were built at the time when bombs were light enough to be dropped by hand from the cockpit.
By the s, the quality of aerial weapons and the means to deliver them had improved markedly. The mids saw the Naval Construction Office in Berlin give the problem serious thought. Various factions in the navy were convinced protection for the expanding U-boat arm was required. A Royal Air Force RAF raid on the capital in plus the occupation of France and Great Britain's refusal to surrender was enough to trigger a massive building programme of submarine pens and air raid shelters.
Others swiftly followed. It was soon realised that such a massive project was beyond the Kriegsmarineand the Todt Organisation OT was brought in to oversee the administration of labour. The local supply of such items as sand, aggregate, cement, and timber was often a cause for concern. The steel required was mostly imported from Germany. The attitudes of the people in France and Norway were significantly different.
In France there was generally no problem with the recruitment of men and the procurement of machinery and raw materials. It was a different story in Norway. There, the local population were far more reluctant to help the Germans. Indeed, most labour had to be brought in. Several metres of silt also had to be overcome. The incessant air raids caused serious disruption to the project, hampering the supply of material, destroying machinery, and harassing the workers.
Machinery such as excavators, pile driverscranes, floodlighting, and concrete pumps which were still a relatively new technology in the s was temperamental, and in the case of steam-driven equipment, very noisy.
Bunkers had to be able to accommodate more than just U-boats; space had to be found for offices, medical facilities, communications, lavatories, generators, ventilators, anti-aircraft gunsaccommodation for key personnel such as crewmen, workshops, water purification plants, electrical equipment, and radio testing facilities. Storage space for spares, explosives, ammunition, and oil was also required. There is no truth in the rumour of an underground bunker on Fuerteventura in the Canary Islands.
This story was gleaned from a similar situation in Le Havre in France when captured U-boat men were interrogated by the British. Pens were constructed in the northern coastal ports of the Reich and in many occupied countries. The "Hornisse" bunker was not started until in Bremen ; it was never completed. Begun init was built to be a manufacturing facility, where Type XXI submarines were to be constructed.
It too was never completed. Post-war, it was briefly used as a test site for British and American bombs most of the damage done to the bunker was inflicted at this time  before becoming a storage facility for the German Navy. The labour to construct it was supplied by local concentration camps such as Neuengamme in Hamburg. The Finkenwerder bunker was constructed by 1, slave labourers over four years. After capture, it was demolished with 32 tonnes of bombs.
It was left alone until near the end of the war when it was attacked by the RAF and like most of the facilities on the island, completely destroyed.Credit: Image from the Public Domain. Development of Schnellboots were not restricted by the Versailles Treaty following the end of World War 1 - hence German construction of the type prior to World War 2. The United States decided not to sign the treaty though acting as a formal ally of both France and Great Britain during the war.
Despite the treaty, German engineers went along designing various weapon types using new technologies while always working to outmaneuver the Versailles Treaty restrictions German was allowed a small standing army, armored cars, some small arms and no tanks, capital ships, aircraft or submarines.
Such workarounds were managed by all branches of the German military - pilots trained on gliders and capital ships such as the KMS Bismarck were built heavier than the treaty allowed by false dimensions provided to the world by the German government.
However, some developments unintentionally adhered with treaty restrictions and led to creations like the "S-Boot" - essentially a scaled-down warship too small to be regulated by the Versailles treaty. Its sturdy design fulfilled a required operational role and the decision was to build boats of high quality over a mass production was the German way of waging war. The beginning of the torpedo boat program was a speedboat designed as a "submarine chaser".
The German Naval Command began development in with series of trials using a variety of designs for boats suited for action in North Sea conditions. Hulls, commonly used for speedboats, were built with a surface-skimming qualities best suited for fast boats in calm waters. The North Sea required a different sort of boat design that allowed a robust hull to "plow" through heavy seas while not producing a highly visible plume of water at the stern.
Inafter many tests in the North Atlantic, German Naval Command settled on a rounded-bottom hull. They chose the hull of the "Oheka II", a luxury motor yacht built in by the German boatyard Luerssen. The hull measured 73 feet, 8 inches During sea trials, the boat ploughed through the water with plume as required, even when all three of her Maybach horsepower engines were used. The rounded hull was made of wood planking to help reduce the weight and flattened at the stern area so the aft section area in water at high speeds was reduced, allowing more hydrodynamic lift when keeping the craft on a horizontal plane.
In November ofthe German shipbuilder Luerssen was given a contract to build a boat to the new military-quality design. Two torpedo tubes were added along the forward castle and the engines upgraded for increased speed. It would become the first Kriegsmarine's standardized "Schnellboot" "Fast Boat" and know in its abbreviated form as the "S-Boot" with the designation of "S-1".
With improvements from the field filtered back to Luerssen, the basic design formed all future S-Boots built during World War 2 As the first S-Boots - eventually known to the Allies as "E-Boats" - were produced, additional improvements were being designed almost boat-to-boat.
The second boat, S-2, was built with an advanced rudder assembly intended to reduce stern waves. This upgrade would help keep the boat in a horizontal attitude that increased the stability of the three propellers. Inthe boats produced needed to reserve the bow buoyancy so, starting with the construction of S-7, the hull as adjusted, preventing the boat from nosing deep into oncoming bow waves consistent with North Atlantic heavy weather.
During the construction of S, the boat's superstructure was constructed so the boat's commander could stand on deck behind a wind and spray screen. This made communication difficult, requiring the commander to issue orders through a voice tube or by a seaman equipped with a headset intercom relaying information to the helmsman, navigator, and radio operator housed behind him in the wheel-house. Bywhen S was constructed, a cockpit was added into the wheelhouse roof area.
This addition allowed some shelter for the commander against the elements and increased visibility from a perched central location on the boat. An advantage of this change allowed the commander to speak orders directly to the crew in the wheelhouse without voice tubes.At the time of its development, long-range fighter aircraft such as the North American P Mustang were just entering quantity production, and thus were not yet available to accompany bombers all the way from England to Germany and back.
Work on the prototypeProject V, began in September by converting the second production BFBO serial number built. Conversion work was done by Lockheed's Vega company. The aircraft differed from the standard B in that a second manned dorsal turret was installed in the former radio compartment, just behind the bomb bay and forward of the ventral ball turret 's location.
The bombardier 's equipment was also replaced with two. The existing "cheek" machine guns on the sides of the forward fuselage at the bombardier stationinitially removed from the configuration, were restored in England to provide a total of 16 guns, and the bomb bay was converted to an ammunition magazine.
Additional armor plating was installed to protect crew positions. Part of the decreased performance was due to the weight increase, and part was due to the greater aerodynamic drag of the gun stations. The first flight of the XB was on 10 November The first order of 13 YBs was made in October A follow-up order for 12 more was made in January The modifications were performed by Douglas Aircraft at their Tulsa, Oklahoma center, and the first aircraft were completed by the end of March A variety of different armament configurations was tried.
Some YBs were fitted with four-gun nose and tail turrets. Externally, the XB had the symmetrical waist windows of the standard BF and the second dorsal turret integrated into a dorsal fairing. In contrast, most of the YBs had the positions of the waist windows staggered for better freedom of movement for the waist gunners, and the aft dorsal turret was moved slightly backwards so that it stood clear of the dorsal fairing. The YB's mission was to provide a heavily armed escort capable of accompanying bombers all the way to the target and back.
Of the initial order of 13, one serial was lost on the delivery flight from Iceland to the UK in May ; it force-landed in a peat bog on a Scottish island after running out of fuel.
Although removed to Stornoway and repaired, it never flew in combat. Altogether of the 59 aircraft dispatched, 48 sorties were credited. Tactics were revised on the final five missions by placing a pair of YBs in the lead element of the strike to protect the mission commander. The original design concept of the YB never played out as intended in practice. Luftwaffe fighter chief Adolf Galland considered the gunship's handful of combat victories to be "insignificant" and not worth the cost of the aircraft.
Boeing YB-40 Flying Fortress
Despite the overall failure of the project as an operational aircraft, it led directly to the Bendix chin turret's fitment on the last 86 Douglas-built BFDL production block aircraft,  and were part of the standardized modifications conspicuous on the final production variant of the B, the BG :. Once the test program ended, most of the surviving aircraft returned to the U. It was returned to the United States on 28 March The wartime "Schatzgrabber" "Treasure Hunter" in German weather station was built by the German military in on Alexandra Land, one of the isolated Franz Josef Land islands in the Barents Sea, located more than miles 1, kilometers north of the Russian city of Arkhangelsk.
The islands are snowy and ice-bound for much of the year and the site was last visited in the s, the researchers said.
But earlier this year, in August, a Russian archaeological team was able to explore and catalog the remains of the wartime weather station for the first time. Among the finds are the remains of several German army and naval uniforms, and fragments of weapons and ammunition — including rifle and machine-gun rounds, land mines and hand grenades — that were abandoned when the last of the base's occupants were evacuated by a German U-boat in About 10 German meteorologists and laborers were stationed on the island fromas part of a secret network of Arctic stations to give advanced warnings of weather conditions over the northern oceans and northern Europe, which the German military considered essential to their strategic operations.
Ermolov said the research team recovered more than objects from the remains of the base station buildings, an emergency supply depot near the base station and an emergency aircraft landing strip. These artifacts have been sent to the Arctic National Park museum in Arkhangelsk for further study, the researchers said.Decisive Weapons S02E04 - U-Boat Killer: The Anti-Submarine Warship
Ermolov said the very dry and almost microbe-free environment of Alexandra Land also helped to preserve many wood, leather and cloth objects at the sites, as well as many remains of books and documents, including German naval manuals, meteorology textbooks, astronomical tablesweather records, magazines and a copy of Mark Twain's classic novel "Tom Sawyer.
The research team also found supplies of canned food at the base, including sardines from Portugal, curiously labeled in English that they were for sale in America. But sardines weren't the only thing on the wartime menu in Alexandra Land.
The waters of the bay beside the weather station began to freeze as the winter approached, and several boats filled with supplies and equipment were crushed by ice, the researchers said. It is no surprise that they wanted some fresh meat, and so they killed polar bearsbecause that's all there was," Ermolov said. But he added that the weathermen failed to cook the bear meat properly, and almost everyone who ate it suffered a bout of trichinosis, a painful and unpleasant roundworm infection caused by eating contaminated meat.
In response to the medical emergency at Alexandra Land, a daring rescue flight set out from a German air base at Banak, in Norway, in Julyto carry a doctor to the island and to bring back the stricken weathermen, according to the German historian Franz Selinger. But the large FW "Condor" aircraft damaged a wheel when it landed and a second aircraft had to be sent from Banak to airdrop a replacement wheel so that the first aircraft could take off with the medical evacuees.
Ermolov said the researchers had to search a very large area, but they were fortunate to find traces of the emergency airfield, including the remains of fuel barrels, tents, batteries, crates, smoke bombs and signal flares made in A team of German military specialists also visited the islands in the s to remove the minefields that had been planted around the wartime base to protect it from an assault, Ermolov said.
But he added that this summer was the first time that the site has been comprehensively studied and recorded since it was abandoned.
The cryptic name of the weather station, from the German word for Treasure Hunter, has fueled speculation that the secret base on Alexandra Land was used for more than keeping a watch on the Arctic weather. Some theories suggest the base was occupied by a unit of Nazi SS troops and may have had a role in the development of secret weapons, or a search for a mythical "Nordic homeland" in the islands of the Arctic Circle.
But polar historian William Barr told Live Science that the base was strictly a scientific base, and one of about 10 German weather stations on the scattered Arctic islands north of Europe albeit an ill-fated one.Heinz-Eugen Eberbach UU Follow us on Twitter uboatnet.
The German U-boat of World War Two was designed to operate mostly on the surface and submerge only for evasion or for rare daylight attacks. In the surfaced U-boat was even more secure near a convoy than submerged as the allied ASDIC could detect him underwater but was useless against a surface vessel. It was only with the continued Allied inventions that the U-boat was forced to spend more and more time underwater and then it was only running on a limited electric motors which only managed a few knots and had very limited endurance.
In when the German army defeated the Netherlands a stroke of luck landed up on the German Navy, namely the Dutch invention the German called somewhat rudely the Schnorchel. The Dutch navy had been experimenting as early as on the submarines O 19 and O 20 with a simple pipe system which enabled a periscoping submarine to operate its diesels and thus have almost unlimited underwater range.
Earlier experiments with this idea by the Dutch Navy had begun earlier in the inter-war period. The German Navy paid little attention they actually thought about this system in as a means to take fresh air into the boats but saw no need to run the diesels underwater and in fact had the schorchel removed from the 3 captured Dutch submarines UD-3UD-4 and UD-5 in 1 The Royal Navy also did the same with the Dutch boats that escaped the German forces.
It was not until when more and more U-boats were lost to the Allied counterattack that the system fell into favor with the high command. Above is the Schnorchel installation on board the U The boat is on display at Laboe, Germany. The first boat to be fitted with the Schnorchel was U which experimented with the equipment in the Baltic during the summer of but operational boats didn't start to use it until early and even as late as June only about half of the boats stationed in the French bases had Schnorchels fitted.
On type VII boats the folding mast was fitted on the port side see photo on the left while on the IX types the mast was on the starboard side. Second were the various disposal problems associated with the permanently submerged boat; garbage had to be stored internally and further fouled up the boat.
Third was the problem with the initial schnorchel masts that they tended to close up and thus the diesels, being starved of air from above, sucked all available air from the boat itself and causing extremely harmful ear pains and sometimes even damaged ear drums.
Events on this day What happened on 18 July? U-boat of the day U - 5 patrols 3 ships sunk 7, tons. U-boat Finder. Over 21, ships. Technologies The Schnorchel. Enter your search terms. The Floating valve type left is seen here with the rare but sophisticated Naxos radar detector mast.