(Type VIIA image). The Type VII‘s design was based on the Finnish Vetehinen-class submarines built in Finland in 1930. They were single hull boats with the pressure hull forming the outer hull in some areas. These submarines had a central ballast tank along with two in the bow and stern and two more on the sides of the hull. They were armed with 533mm torpedo tubes, an 88mm gun installed in front of the conning tower and a 20mm anti-aircraft gun installed in the aft.(Type VIIC image). The pressure hull was built with a 22 mm thick welded rolled steel plate and the submarine consisted of six circular sections plus a bow and stern end cap. Surrounding all the pressure hull was the external casing, leaving the space between them for free-flooding, housing ventilation ducts and storage areas. Between the deck and the highest part of the pressure hull there was a large space occupied by ducts and pipes as well as by the mounting on which the 88mm gun was located. There was also the gun locked system, a small dinghy, ammunition for the gun, and some reserve torpedoes. These spaces could be accessed through hatches or by lifting the deck plates.(Type VIIB image). The external decking of these submarines was of wooden planks to prevent as much as possible their freezing in winter conditions. The outer casing had numerous draining slots, which were distributed in different ways and numbers depending on the manufacturer. Between the outer casing and the pressure hull at the front there used to be a tube with a reserve torpedo in it or life rafts. Also in the forward part of the submarine was the hatch through which the torpedoes were loaded and behind this a small watertight magazine with ammunition for the 88mm gun. This allowed a quick use when necessary.(Type VIIB image). A retractable hydrophone array and a retractable winch were installed on the foredeck and retractable bollards were distributed in various parts along the boat as railings. There were differences between the conning towers of these submarines as the War progressed. Here, there were the supports for the periscopes and the aiming system for the torpedoes, called “uberwasserzieloptik” or “UZO”. In the last series the snorkel tubes were also installed here. Finally, at the stern of the outer casing there was a hatch through which the torpedoes were loaded for the stern tube, leaving this area clear of elements of any kind.(Type VIIC/41 image). The Type VII had different engines according to the sub-types. The VIIAs carried two MAN M6V 40/46 diesel engines for surface and two Brown, Boveri & Cie GG UB 720/8 electric motors when submerged. The VIIBs carried two supercharged MAN M6V 40/46 or two supercharged Germaniawerft F46 diesel engines for surface and two AEG GU 460/8-276 electric motors when submerged. Finally the VIICs carried two MAN M6V40/46 or two supercharged Germaniawerft M6V 40/46 for surface and two AEG GU 460/8-276, or two Brown, Boveri & Cie GG UB 720/8, or two Garbe, Lahmeyer & Co. RP 137/c or two Siemens-Schuckert-Werke (SSW) GU 343/38-8 electric motors when submerged.(Type VIIC image). The Type VIIs originally used the two standard Kriegsmarine torpedo types. They were designated as G7a and G7e and were Whitehead-type torpedoes with different guidance and detonation systems. The G7a had a range of 6 km and a top speed of 44 knots (81 km/h) and the G7e had the same range and a speed of only 30 knots (55 km/h). Despite being much slower, the G7e left no visible trail as it headed towards its target, making it highly appreciated by crews. The G7a, however, left a trail of bubbles that warned of its trajectory.(Type VIIB image). Two new torpedoes designated as T5 “Zaunkönig” and the Fat (“Flachenabsuchender (shallow searching) torpedo”) were subsequently deployed. The first was acoustic guidance and the second zigzagged randomly before hitting. The T5 was unsuccessful, since the British knew about it before its entry into service and created sound countermeasures (decoys), however the Fat (or Lut) always ended up hitting one of the ships in the convoy, which is why it became very popular. Anyway, at the end of 1944 the T5 was improved and reached a full effectiveness. Until now, the torpedo was directed to the ship that emitted the most noise in the enemy formation, but there were cases in which the torpedo turned against the submarine that had launched it.(Type VIIC/41 image). The main compartments of the Type VII submarines were as follows, from bow to stern: bow torpedo room, the senior non commissioned rank’s accommodation room, the officer’s accommodation room, the commander’s bunk along with the radio and sound detector rooms, the control room or “zentral”, the junior non commissioned rank’s accommodation room, the engine room and the motor room. Anyone can see what these compartments really were like by watching the exceptional movie entitled “Das Boot”, directed by Wolfgang Petersen in 1981 and which takes place mainly inside the U-96 (Type VIIC) submarine.(Type VIIC/41 image). The bow torpedo room contained four tubes and a roof-mounted system for handling the torpedoes, as well as the hatch through which they were loaded into the submarine. There were three double bunks for junior ratings and compressed air cylinders, as well as a few folding tables. Under the deck of this room were housed two reload torpedoes and under them two bow trim tanks. Only four double bunks were installed in the senior non commissioned rank’s accommodation room.(Type VIIC image). The officer’s accommodation room housed two more double bunks, but typically only three were used. The commander was the only crew member with a tiny quarter, separated by a simple curtain. The radio and sound detector operators were placed in this area of the boat to dispatch instantly with the captain if necessary. Under the deck in this area, ammunition was kept for the 88mm gun and the front batteries were installed.(Type VIIC image). Following the officer’s accommodation room, was the most important area of the submarine, known as “zentral”. The boat was controlled entirely from here and where the periscope motor, ventilation controls, the main bilge pump and the drinking water tank were. The optical and navigation elements were also here. Above this space was the conning tower, where the commander’s attack station was. This station had the attack periscope, a compass, the attack computer and the hatch that allowed to go outside the conning tower. Under the deck of this compartment were some fuel tanks and ballast tanks.(Type VIIB image). Behind the “zentral” was the junior non commissioned rank’s accommodation room which contained eight double bunks, the small kitchen, the aft w.c. and a small pantry. Under the deck in this area were the aft batteries. The next compartment was occupied entirely by the two diesel engines, followed by the room with the two electric engines. All the engines were coupled to the two shafts of the submarine. In this last compartment were the electrical controls, a compressor for refrigerated storage and the aft torpedo tube, which was installed between the two rudders of the boat. Under this deck were the stern trim tanks.(Type VIIC image). The 703 Type VII submarines were built by 16 different companies. They were the following: Blohm & Voss, Hamburg (181 boats), Bremer Vulcan, Vegesack (74 boats), Danziger Werft, Danzig (42 boats), Deschimag, Bremen (6 boats), Deutsche Werke, Kiel (30 boats), Flender Werft, Lübeck (42 boats), Flensburger Schiffsbau, Flensburg (28 boats), Germaniawerft, Kiel (80 boats), Howaldtswerke AG, Kiel (65 boats), Kriegsmarinewerft, Wilhelmshaven (29 boats), Neptun Werft, Rostock (10 boats) , Nordseewerke, Emden (30 boats), Oderwerke, Stettin (2 boats), Schichau-Werke, Danzig (64 boats), Stülcken Sohn, Hamburg (26 boats) and Vulcan, Stettin (1 boat).(Type VIIB image). While the Type VIIs were not excellent boats, they did dive quite quickly, which made them safer than other German submarines. However, the internal space was too small, which had an unfavorable influence on the crews, as well as the number of torpedoes carried on board and the limited range. They were boats designed to operate in the North Sea and neighboring Western waters, but they were mechanically reliable. Thanks to their huge number they were the most influential German submarines in WWII.(Type VIIA image). It is estimated that the Type VII carried out some 2,600 war cruises in which about 400 boats were lost by enemy action, and in most cases with all hands. It is estimated that almost 1,400 enemy ships were sunk, of which 190 were warships. Around 70% of the crew members who died in German submarines did so in a Type VII boat. The first Type VIIs to enter service were those of the VIIA sub-type in 1936. Its distinctive visual feature with the rest of the boats was a “hump” on the external stern torpedo tube, on the aft deck. Ten units were built that carried numerals from U-27 to U-36.(Type VIIB image). The sub-type VIIBs carried some improvements such as more fuel capacity, twin rudders to improve their turning capacity and the installation of the stern torpedo tube inside the pressure hull. Turbochargers were installed in the diesel engines and compensating tanks were installed, which were filled with sea water as the fuel was consumed, in this way the danger of rolling was avoided when navigating on the surface. The increased fuel load allowed the surface range to be extended by about 4,600 km. These submarines were 2.10 meters longer and about 120 tons heavier than the VIIA. 24 boats of this type were built.(Type VIIB image). Some VIIB submarines were operated by some of the most famous U-boat aces. Like Gunther Prien’s U-47 that on October 14, 1939 sank the battleship HMS Royal Oak in Scapa Flow or the U-48, which was the most effective of the entire war, having sunk 55 ships totaling 321,000 tons. Other aces such as Otto Kretschmer and Joachim Schepke also served on VIIB submarines, the U-99 and the U-100 respectively.(Type VIIC image). Without doubt the most successful sub-type was the VIIC, of which 568 units were built between 1940-45. These boats carried a new S-Gerät active sonar and some minor mechanical improvements. These submarines were 60 cm longer than the VIIBs and about 8 tons heavier. However, the general characteristics were similar to those of the VIIB, carrying 14 torpedoes and having a range of about 15,700 km. From 1944 snorkels were installed in many of them. This sub-class in turn had two variants, VIIC/41 and VIIC/42, but the last did not enter in service. Of the first variant, 91 boats were built, but of the second variant, none were completed.(G class image). On May 1, 1942, U-573, belonging to the Type VIIC class, was in the Mediterranean when it was attacked by a RAF aircraft that damaged it with two depth charges. The next day the submarine managed to reach the Cartagena Arsenal in Spain. Her intention was to be minimally repaired in order to return to Germany, but a series of problems with the interpretation of the role of the Neutral nations in these cases, made this not possible. In addition, the Spanish submarine specialists soon wanted to be able to access the submarine and evaluate its modern equipment such as the submarine telephone or its great hydrophonic equipment, composed by 46 elements.(G class image). After various negotiations with the Kriegsmarine, the Spanish Navy ended up buying the U-573 for 1.5 million Reichmarks, about 6.5 million pesetas of the time (39,000 euros). On August 2, the submarine was commissioned with designation “G-7” but it would not enter service with the Submarine Flotilla until November 1947. The reason for this huge delay was the state in which the U-573 was transferred to Spanish hands. In addition to the damage caused by the RAF ASW aircraft, we had to add the damage caused by the crew before abandoning it and the shortage of original spare parts and specialists to repair it.(G class image). On June 15, 1961 its designation was changed and it became “S-01”. For 23 years in a row she became a true “master” for the Navy submariners. She was discharged on May 2, 1970, exactly 28 years after arriving in Cartagena. Unfortunately the ship was totally scrapped, missing an excellent opportunity to have been able to turn it into a unique museum, but in those years, the military culture in Spain was not cared for at all, a shame.(Type VIIC/41 image). The VIIC/41 variant had some modifications with respect to the VIIC such as a 2.5mm thicker pressure hull that allowed increasing its diving depth from 100 to 125 meters and the crush depth from 250 to 300 meters. Lighter machinery was installed and many electrical elements were changed, which saved about 11 tons of weight, although its length was increased by 10 cm to improve seaworthiness. Submarine U-995 has been preserved as Laboe Naval Memorial in Kiel since October 1971.(Type VIID image). The Type VIID were designed as minelayer submarines and a 10-meter hull section was added to allow it to carry more fuel, new trim tanks, more food storage and 15 mines. The mines were carried in three banks of five vertical tubes, from where they were launched. They maintained the armament of the other Type VII submarines and their range increased, although speed and maneuverability was impaired by the increased weight.(Type VIIF image). Four Type VIIF submarines were manufactured that served as resupply submarines. They had an extra section of 10.50 meters which allowed them to carry an additional 24 torpedoes, two extra crew members and refrigerated food. Their mission was to reload torpedoes to first-line submarines that had spent theirs. This subclass kept the same armament as the rest, except that it lacked the 88mm deck gun.(Type VIIC image). It is said that Hitler’s alleged flight to Argentine lands at the end of WWII could have occurred in the submarine U-977 (Type VIIC) commanded by Heinz Schäffer that left Kristiansand, Norway. It is said that the submarine had been specially conditioned and the amount of fuel increased in order to reach Argentina directly. This hypothesis has the support of several researchers, who after questioning the testimony of Hugh Trevor-Roper, a British historian who wrote about Hitler’s last days, have investigated the confirmed crossing of this submarine to Argentina, where it was handed over to the authorities in July 1945. Mr. Trevor-Roper’s book was questioned years ago after admitting that he had not spoken personally with the people who claimed to have seen Hitler’s corpse in the Reich Chancellery, so this hypothesis of Hitler’s escape could have some hint of reality.
