by Ryan Jenkins
To make sure that the Tirpitz never made it out of port, the British came up with a variety of ideas, most of which turned out to be untenable. One that might have succeeded was to launch human piloted torpedoes from small patrol craft away from her anchorage, but when the time came and this operation was about to be carried out, rough weather forced its cancellation.
The fjords of Norway allowed for easy defense of an anchorage: narrow openings meant they could be mined easily as well as watched by troops and guns on the high shores on both sides of the waterway. In addition to the mines, chains, sonar and radar might detect or disable larger ships and submarines. Launching an air attack was equally difficult – guns ringed the mountains near all the fjords where the Germans based ships, and made accurate bombing and strafing runs very problematic. The last fact settled the matter: the Germans had moved the Tirpitz north out of range of British bombers.
The British were perhaps the most creative and innovative thinkers during the war, and the minds of the Royal Navy were constantly working to find a way to sink the Tirpitz. The British decided that they would entrust the destruction of the German battleship to what they called “X-Craft”- midget submarines.
The X-Craft was fifty-one feet long, and five feet in diameter. Like their larger cousins, they were powered by diesels and battery power. The craft had a three-man crew, sometimes four, and carried two charges made of amatol, which combines TNT and ammonium nitrate. These charges weighed over 8,000 lbs.’ – enough to blow a battleship apart. Powerful magnets helped fasten the charges to their target.
These craft had a submerged range of eighty-two miles, which could see them into the furthest fjords, but they were slow, both submerged and surfaced. They were capable of diving to three hundred feet, and the canyon like fjords could reach that easily. In the narrow passages of the fjords, depth might save the sub.
In March 1942, sea trials were held for the X-Craft, and six were built by the beginning of the next year. The mission to destroy the Tirpitz was supposed to take place in the summer, but a combination of increased training and a desire to avoid the long daylight hours of the Arctic summer caused the British High Command and Prime Minister Churchill (who was personally involved with the details of the mission) to postpone until later in the year.
In early September 1943, Soviet based RAF fighter planes took pictures of the Kaa Fjord and its approaches where the battleship was anchored. Naval intelligence analyzed the photos and the defense of the fjord and the most formidable of them or at least of most concern to the commanders of the midgets was the anti-torpedo nets around the area, which could stop or even entangle the small boats.
Another of the factors that came into play was moonlight. In order to attack under the darkest possible conditions, the attack had to take place between the 20th and 25th September. This required swift action as a sizable number of other vessels supported the X-Craft. Each of the six midgets was towed by a regular submarine to within range after the X-Craft was taken off the coast by a larger vessel. A submarine supply ship was also included.
The Tirpitz was not the only target of the fleet of six midgets. Another smaller battleship, the Scharnhorst (which the British had been wanting to sink for nearly four years), and the cruiser Lutzow. Three subs were assigned to sink Tirpitz (X-5, 6 and 7). Commanding the X-5 was Lieutenant Henty-Creer, who was also in command of the small fleet.
Before the mission even really began, it seemed cursed. The X-9 went down in rough seas after its tow cable separated it from its mother sub. Another midget, the X-8 was intentionally sunk after it partially flooded through mechanical damage. The X-7's towrope broke close to the release point and a German mine washed over the deck and rested there. A swift kick by the subs' commander got rid of it. The X-5 and X-6 made it into the fjord without incident. The last of the subs, X-10 was to target the Scharnhorst, but that ship unexpectedly left the anchorage and the midget could not follow her. Returning to her mother ship, this midget too had problems and was scuttled.
What was left of this unfortunate mission luckily was designated to attack the prime target, but they were still beset with problems. Passing sea trials was one thing, but now it seemed that the gods of the sea were determined to prevent the subs from completing their mission. X-6 commanded by Lt. Cameron started to list underwater when one of its charges began to flood, its periscope starting leaking. However, not all luck was bad and even as they could not see while submerged, the X-6 closely followed a small coastal patrol boat and made it through the anchorages protective netting as it opened to let the German ship by.
The Tirpitz loomed in the distance, a hastily repaired periscope allowed the X-6 to submerge and approach the battleship. For a moment, the midget ran aground, and Cameron surfaced the boat to avoid being stuck on the bottom. Luckily, he was not spotted and submerged again, inching closer to the huge German vessel. As he approached, the sub broke the surface of the water and he was spotted by crewmen on Tirpitz.
By this point, the periscope again was leaking and now the compass was not working and the warship was aware of the midgets' presence. Diving despite his problems, Cameron steered by hunch and brought his boat to the port bow of the battleship, surfacing once more right alongside. As men from the battleship began to fire down at the sub and drop explosives into the water, X-6 dropped its large charges right next to the ship's second turret. At this point, the little sub was nearly inoperable, and the captain ordered his men to abandon ship after placing explosive charges in their boat. The men of the Tirpitz soon captured him and his crew.
X-7, under its commanding officer, Lt. Place maneuvered her through the anti-sub barriers, but both the hull and some of its equipment were damaged. Finally getting himself clear of the barriers, Place moved next to the battleship and actually bumped into the side of the hull before he released his charges next to the third turret just aft of the battleships' bridge. As X-7 moved away, she too was spotted and taken under fire. As she moved away from the battleship, she became entangled in the anti-sub barrier.
No one is sure what the X-5 did for the little sub was lost, destroyed by guns of the Tirpitz sent her to the bottom as the midget moved away, some six hundred yards from the battleships' bow after the following events. Her exact role has been the focus of many naval historians and sleuths since the end of the war.
At this point, the captain of the German battleship, Hans Meyer, ordered his ship to power up and moved out into the waters of the fjord. Seeing the action on the port side of his ship where his men were firing at X-7, Meyer ordered his ship to move to starboard, and that took him away from three of the charges that had been planted. Still, at 8:12 pm, a huge explosion erupted from the starboard side of the ship. An even bigger explosion went up to port. Most people believe that in addition to the charge left by Place and X-7, the X-5 planted a charge (or had one prematurely detonate) which was also destroyed the sub and its small crew.
The German ship took massive damage. All of its working machinery came unbolted from its positions throughout the ship and much was rendered inoperable. The 43,000-ton ship was actually lifted from the water by the blast of the midgets' bombs. One of its turrets was blown off its mounting and the other two were damaged. Rudder and drive shafts were heavily damaged – the ship was not moving for a long time. Though the Germans talked about repairing the ship, they never did. One symbol of the British nation is the bulldog, and once they got their teeth into the Tirpitz, they were not going to let it go – not while she was afloat. Repeated attacks by the Royal Navy and finally attacks by heavy bombers stationed in Europe after D-Day put Tirpitz under the waves forever.
For their part in the raid, Captains Price and Cameron were given the Victoria Cross and their crews given the Distinguished Service Cross or Conspicuous Gallantry Medal. The crew of the X-5 was hailed as heroes who gave their lives for the nation, but were never given citations, as their role in the raid could never be determined.
The Seehund series o
f submarines were another type of midget submarines that were used by the Germans during the end of World War II.
The Seehund, which was also known as the Type XXVII, was a series of midget submarines designed by the Germans. Seehund mean seal in German. Theses submarines were designed during the end of World War II. They were two man submarines that made them useful. Owing to the fact that they needed just two crewmembers, a large number of these submarines could be manned without a waste of resources. They were used by the Kriegsmarine during the last stages of the war.
The idea for Seehund began when 2 X-class submarines, HMS X6 and HMS X7, which had been sent to the bottom during the Operation Source, were salvaged. Hauptamt Kriegschiffbau, which was the office for the design of warships proposed a design for two man submarines based off the British X class. The submarines made from these first designs were known as Type XXVIIA or Hecht.
The Type XXVIIA is similar to the British X class boats in the sense that it was also designed to carry explosive charges to be placed underneath enemy ships. However, the significant difference was that the Hecht was much smaller than the X class submarines. Instead of a dual diesel and electric propeller system that was favored by the X class submarines, the XXVIIA used only electric power by using a single 12-horse power AEG torpedo motor. The logic is that once the submarine is underwater it will not need the diesel engine. However, the removal of the diesel engine resulted in the lesser durability. It could now only run for 128 km at 4 knots.
Submarines need to pass through the anti submarine nets and other obstacles, which is why they were initially designed without fins or hydroplanes. Her trim was controlled with adjustable weights within the hull. However, practically that didn’t work so well. It was completely ineffective because the weights were too heavy to move quickly enough. Hence, fins and hydroplanes were eventually fitted in. Control underwater was still poor because of a lack of ballast tanks.
Despite the Hecht having the facility to carry an explosive charge, Karl Donitz an Admiral in the German Navy wanted the submarines to carry a torpedo in the event that they had the opportunity to attack other boats in coastal water. This led to a change in design to allow the submarines to carry either an under slung mine or an under slung torpedo along with a limpet mine in the nose.
From the outside, the Hecht resembled the Welman submarine designed by the British. The explosive charges were added to the nose of the submarine and the forward compartment had the battery and gyrocompass. The addition of the gyrocompass was the first to ever be used by a German midget submarine. The gyrocompass is essential for navigation when the submarine submerges. Behind the battery and gyrocompass was the control compartment. This section of the submarine had the seating for the two-man crew. The seats were arranged one behind the other in the center. The engineer usually sat in front while the commander sat at the back. The commander’s seat had access to a periscope and it also had an acrylic dome through which is he could see outside. This was fitted for navigational purposes.
The fifty-three Hecht submarines were built between May and August 1944. However, none of these boats saw any kind of action. They were used exclusively to train crews for future Seehund crews.
These submarines could also carry a diver in the nose in the place of a mine.
As Hecht was being built, there were also discussions going on about variations of the existing design. The first variation was the Type XXVIIB. This version of the Hecht had a much greater range than Type XXVIIA. It could also carry two G7e torpedoes. It also had a diesel and electric propulsion system. The design was ready by the end of June 1944. The final plan showed a submarine that was very similar to Type XXVIIA in outer design. However, it had a better shaped external covering, which helped improve the sea keeping while breaking out onto the surface. It also had saddle tanks that were missing from Type XXVIIA. There was also extra space in the hull because the batteries had been moved to the keel. The torpedoes were thrown externally in the lower structure. A 22 hp diesel engine was added. This allowed for better movement at the surface. This engine gave a speed of 5.5 knots. The submarine was also designed to have a 25 hp electric motor for use underwater. The electric motor gave the submarine a speed of 6.9 knots.
The final variation of the Seehund was the Type XXVIIB5. This was also known as Type 127. When people mention Seehund, they most likely refer to this model from the entire series of Seehund submarines. This model had some significant changes from the previous two models. It had a raised platform in midship with an air intake pole, periscope, and magnetic compass and clear dome. This could survive depths up to 45 meters or 148 feet. The periscope had a length of 3 meters or 9.8 feet and was fixed with lenses that allowed the commander to check the skies above the sea before allowing the submarine to surface. The safe diving depth for this submarine was 30 meters. However, some trial boats showed that around 70 meters could be accomplished without any problems. This model incorporated all the changes that were needed in the earlier editions and was as close to perfection as physically possible. This model was designed by Dr. Fischer and Grim who were a part of the German Naval Construction Board.
The first contract for the construction of the final version of Seehund (Type XXVIIB5) was placed on July 30th 1944. The design of this submarine was so popular that most of the contracts were allocated even before the final design had been approved. A total of 1000 boats were ordered. Germaniawerft, a ship building company based in Kiel and Schichau-Werke, engineering and shipyard based at Elbing were instructed to churn out twenty-five and forty-five boats per month respectively. Several other centers such as the CRD-Monfalcone at Adriatic and Klockner-Humboldt-Deutz at Ulm were also responsible for the construction of these submarines but not on as large a scale as Germaniawerft or Schichau-Werke. Donitz, however, did not allow the production of the older Type XXVIIA to be halted just to promote the Seehund construction. The added stress of shortage of raw materials, transport and labor restricted the number of Seehund submarines that were constructed. In the end the production of this submarine was done at the Germaniawerft at Kiel at the facility that had previously been used for the production of Type XXI and Type XXIIII. Since there was no more production of those two types of submarines, the production of Seehund was given to that center. In total, around 285 Seehunds were constructed and used for active service in the war. They were assigned numbers from U-5501 to U-6442.
The Seehund was first used in combat on December 31st 1944 when 18 submarines set out from IJmuiden, a port city in Netherlands. However, this mission was a complete disaster. The 18 boats found themselves in the middle of a storm and only two of them were left afloat after the storm. It was nearly two months later in February 1945 that an Allies ship was sent to the bottom of the sea because of a Seehund. A Seehund sank a freighter near Great Yarmouth.
The Seehunds operated along the English Channel and German coast. During turbulent weather, they could attack on the surface. However, the only drawback was that when they were submerged, they had to be completely motionless to be able to successfully attack any target. Between January 1945 and April 1945 these submarines were sent on 142 patrol and missions and accounted for nearly 93,000 tons of enemy ships. The number of losses they suffered was 35 boats. These losses were mainly because of calamities rather than enemy attacks. The threat of these midget submarines was so high that the Allies diverted a huge number of their planes and ships towards the coastal areas where these midgets were found so that they could search for them and destroy them before they started a coordinated attack of Allied ships.
The small size of the Seehund made it difficult for the Allies version of the sonar, the Asdic to detect her. The small size made it difficult to detect the return echoes from the hull. Also, the slow speed at which the Seehund moves made it difficult for the hydrophone to detect her. As said by the Admiral Sir Charles Little, Commander-in-Chief at Portsmouth, “Fortunately for us these damn things arrived too late in the war to do damage”. The fau
lt in the design that helped the Allies was that when the submarine was damaged, carbon monoxide gas would leak into the cabin of the submarine. A large number of deaths were reported to be due to carbon monoxide poisoning. The longest recorded mission of a Seehund was for 10 days while the average was five days.
The last of the Seehund missions were on April 28th 1945 and May 2nd 1945. These two special missions were done in order to supply the German garrison at Dunkirk where the Allies had staged a siege. The boats carried food containers instead of torpedoes. The food containers were known as butter torpedoes due to the fact that they were stored in the space allocated for the torpedoes. On return from the garrison, the same containers were used to carry all the mail and correspondence.
The French Navy received four Seehunds as reparations of the war and recommissioned them as S621, S622, S623 and S624. These four were in use till the August of 1953.
Most of the Seehunds were destroyed during the war. However, a few remain and are on display across the world. One of the submarines used by the French, S622 was preserved and is on display at Musée national de la Marine in Brest, France. Another Seehund, the U-5075 is at the United States Naval Shipbuilding Museum in Quincy, Massachusetts. In Germany, Seehunds are displayed at several museums including, the Deutsches Museum in Munich, the Technik Museum Speyer, the German Shipping Museum in Bremerhaven and the Marinemuseum Wilhelmshaven.