„Valentin“
In early 1943 the German Submarine High Command stood with the back to the wall. The main reason for this disastrous situation for Admiral Dönitz and his people was the rapid development of radar in England and the USA. Besides this the British Navy happened to crack the news code of the German Navy (Marine). In March 1943 Dönitz assigned the navy armament to Albert Speer, the Reichs Minister for Ammunition and War Production (RUK). Speer should industrialize the construction of submarines and multiply the production numbers
Already before this management decision the Navy had taken the fact into account that the existing mass of boats of the type VII C had become hopelessly obsolete. They were rather over-water than diving boats and offered best targets to the “killer groups” of the British Navy. On June 19, 1943 the shipyard company Deschimag A.G " Weser " in Bremen delivered the prototype of a new submarine generation, the type XXI submarine. It was a further development of the true miracle boat of the type XVIII which provided a Walter drive. At this technical sensation diesel was oxidized by catalytically corroded hydrogen peroxide. This resulted in a carbon dioxide water steam mixture which drove the generator of the boat, the exhaust fumes, or exhaust steam, dissolved completely in the seawater. This meant nothing else that contrary to the conventional boats this type could unlimitedly operate under water. A side-effect of the construction and the drive was also an outrageously high sub-water speed. It could run faster under water than the type VII C boats could run above water. A revolution in the submarine construction had started.
But the new technology was treacherous and took more development time than calculated. Since the course of war allowed no more long development, the new boat type was fitted with the old propulsion system, new more efficient accumulators and improved snorkel technology. The improved battery capacity ensured a sub-water speed of 17.5 knots at one and a half hours of operation, 12 -14 knots in case of a twelve-hour journey and even eleven days under water in case of silent running. That was a technical sensation and a fright for the Allied submarine counter-intelligence.
Speer appointed the president of Magirus Trucks Works, Otto Merker, as chief of the new submarine construction team. Merker was fascinated by the American assembly line production of Liberty ships and thought to use the same principle in the submarine fabrication. Section-building was the magic word. Merker intended to carry out the making in three steps. A decentralised construction of eight sections in inland factories, completion of the ex- and interior on specialised shipyards as well as the final assembly on major shipyards, instead of eleven months to construct a submarine only two were needed with the new method.
The Organisation Todt (OT) was responsible for all great construction projects of the III. Reich, 1.36 million workers formed the OT in 1944. In the 1930s they built motorways and the Siegfried Line, later the Atlantic Wall, the submarine bunker in France, Helgoland and Hamburg and many other large-scale projects like bombproof factories, tunnels and more. Toward the end of 1942 the plan matured to build a gigantic central submarine shipyard. A factory that not only serviced or repaired (like at the Atlantic) but produced as well. Farge, a rural suburb of Bremen located downriver offered all advantages for a perfect location. The river Weser was an economical transport route, two big shipyards lay next-door: Vulkan and Deschimag. Both were in the military sub-area X which almost was turned over exclusively to armament and had correspondingly fully developed stores and infrastructure at their disposal.
The organizational model for “Valentin” provided the following sequence. Two shipyards should build the sections. Sections 1, 2, 7 and 8 with Blohm & Voss in Hamburg, the sections 3,4,5 and 6 at the Deschimag. Two big bunkers were built, "Wasp" on the Blohm & Voss area, "Hornet" in Bremen near the Deschimag. The orders to erect the bunkers were issued at the beginning of 1943 and should result for in record time. “Valentin” already should deliver three boats in March 1945, a monthly production of 14 XXI types was planned for August.
Planning and static of the project was in the hands of the Cologne construction company Agatz & Bock. They designed almost all big buildings for the Marine. Wayss & Friday, Hochtief, Lenz Bau as well as Tesch took on the execution, summarized under the contraction ARGE-NORD. The companies Hermann Möller, Robert Kögel and August Reiners formed ARGE-SÜD. More than 50 companies should participate in the construction site at long last.
The excavations started in summer 1943, the foundation were concreted in October. In Mrach 1944 the entire construction site had prospered, that one could start with the concrete high-rise buildings. The measures of this monster were gigantic. 426 m long, 67 or 97 m wide and 25 m high. The wall thickness was 4.50 m, the ceiling strength 10 m. The mass of gravel, cement and structural steel was so gigantic that material even had to be rushed to the site from the Balkans by train and ship. The difficulties of the procurement of materials increased with the intensification of the Allied bomber attacks. Other projects like aeroplane bunkers had to be deferred to be able to finish the ”Valentin” project.
Although most modern methods were used such as concrete transport by compressed air, between 10,000 and 12,000 people worked daily on the construction site. Most of them were forced labour convicts, concentration camp prisoners, Italian armed forces internees, Russian prisoners of war. Over 4,000 died because of the dreadful working conditions. The daily working time was 12 hours. The wages of Reichsmark 6,- per hour which the building firms had to pay, went directly into the bags of the Reichssicherheitshauptamt (RSHA), the SS Reichs Security Main Office.The provisioning was a catastrophe. Guard Plothe who summoned to an English military court in 1948 stated: "The meal was bad. 1 to 2 prisoners died daily". Another ten defendants were sentenced besides Plothe who went to jail for seven years. Six of them were sentenced to six months and seven years, three defendants, among them the Gestapo's head of administration of Bremen, responsible for clothing and food, Grauer –Carstensen, were acquitted.
“Valentin” was actually a bi-part construction. The 350 metre long assembly hall is prolonged by a 70 metre long sector which housed the workshops, offices, storerooms, heating, smithy and similar. Today this part is used as a material depository by the Bundeswehr, the German Federal Army. In the assembly hangar the assembly line production was slated. This method was new ground for German planning managers. Eight sections had to be fitted together. The beginning of the process was the installation of the diesel engine and the keel ballast. The true assembly line then got started.
Assembly point 1-2: Lay down keel of all sections with new forms where pressure body welding work could be carried out without the boat body having been able to tense up or go out of shape.
Assembly point 3-5: Electric welding in the various sections. To this there were special hanging scaffoldings which had to be removed as of assembly point 6.
Assembly point 6-8: Machine installation, line connection, tank tests, fixing of the “tower”.
Assembly point 9-11: Installation of snorkels and periscopes with the help of a 5 t crane.
Assembly point 12: Work on view instruments, aerials, contribution of the boat equipment as well as load of the accumulators.
Assembly point 13: Launching, submerge- and engine tests.
Three boat motions within the bunker were scheduled: lengthwise, crosswise drive and
launch drive. These were necessary to keep the bunker practicable in extent and form. At the end of the assembly was the tank for the submerge and engine tests as well as for the section delivery . Because of the sensibility of this plant a special bomb protection was installed by two 10 m gates arranged behind each other.
The end came in March 27, 1945. Parts of the interior furnishings were already installed and the sluice dock completed. However, a heavy air raid of the Royal Air Force wrecked all efforts. Two "Grand Slam" bombs of 10 t each struck a not finished yet ceiling area. They penetrated two meters deep into the 4.5 m strong ceiling and exploded. The force nevertheless did not suffice to break through the roof, however, pieces of 1,600 t of concrete fell from the ceiling and wrecked two mobile cranes. Three days later the Americans threw a 2.5 t bomb on the roof. But it did not cause any damage. But construction came to a sudden halt.
However, the operation “Valentin” was only just finished for a shipyard from the north of Bremen in 1971. Until then it tried to assert demands against the OT and Wehrmacht in the amount of 67,8 million Reichsmark from the regional finance office in Bremen.