Type VII u-boats made up a large part of the u-boat fighting force in the Atlantic. This class of fighting ship helped the German Navy reign the high seas between America and England for years and became the face of the U-boat Scourge in general, so much so that its legacy was solidified in Hollywood lore through the motion picture "Das Boot". The Type VII covered six major variants, each improving upon the limitations of the previous design. In all, some 700 Type VII's were known to be commissioned from 1936 through 1945.
The Type VII had its early origins in a 1918 design of the UB III, which was then followed the Finnish-inspired Vetehinen class during the early 1930's. As was the case with other naval treaty limitations in the post-World War 1 world, Germany sought to construct weapons of war with optimized firepower and performance whenever possible while still (somewhat) adhering to the global terms, eventually giving birth to the Type VIIA, of which 10 were produced that weight in between 626 and 745 tons. The ground-work was laid for a line of submarines that would eventually give control of the seas to Germany for an extended length of time.
The Type VIIA series was designed and constructed during 1935-1937 and represented the new generation of German assault boats. Commissioned Type VIIA systems covered U-27 through U-36. These systems replaced the Type II vessels, featured four bow-facing torpedo tubes, a single stern-facing tube and 11 total torpedoes. Power was derived from two MAN AG 6-cylinder diesel engines (surfaced) and 2 x BBC GG UB 720/8 type electric motors (submerged). Performance was good (though fuel capacity was limited) and construction was primarily handled at Deschimag AG Weser at Bremen.
The Type VIIB followed the Type VIIA and tried to fix the fuel capacity limitation. This system appeared throughout 1936 and 1940 and featured external tanks holding some 33 tons of extra fuel. This directly increased the types range and other improvements included a second rudder for better steering control, an increase to overall speed, and an increase in torpedo carrying to 14. Power was a pair of MAN supercharged diesel engines (some fitted with Germaniawerft engines) along with twin AEG or BBC electric motors. The Type VIIB group produced some of the most famous U-boats of the war in this class. Designations covered U-45 through U-55, U-73 through U-87 and U-99 through U-102.
The Type VIIC appeared through 1940 and 1945 and immediately became the star of the Type VII group, making up over 75% of the groups entire total production. These U-boat types were similar in most respects to their two predecessors with the exception of a slight decrease in speed with an increase in overall weight. Some featured varying weapons loadouts but for the most part, diesel and electric engine performance were about the same as earlier models. As this type represented most of the operating Type VII's in the Atlantic, they appeared everywhere a German u-boat scourge was noted. Some 568 commissioned boats made up this powerful group.
The Type VIIC/41 appeared in about 90 production examples and were naturally based on the Type VIIC. These featured a reinforced pressure hull and reworked internal machinery to compensate for the added steel material. Overall, weapons and propulsion were pretty much the same as the VIIC's. Designations covered U-292 through U-328, U-827 and U-828, U-929 and U-930, U-995, U-997 through U-1025, U-1063 through U-1065, U-1103 through U-1110, U-1163 through U-1172, U-1271 through U-1279, and U-1301 through U-1308.
Other Type VII systems considered but never seeing full-blown production were the "U-flak" as four VIIC boats modified for surface escort duty with improved anti-aircraft armament. U-flaks saw initial success until the Royal Air Force adapted tactics when engaging the type, eventually forcing these flak variants back to their original operating duties under the water. Operational service for the converted U-flaks covered June 1943 through November 1943 before the project was abandoned altogether with limited success. The added firepower proved adept at engaging Allied aircraft (of which some 6 may have been shot down in that period) though the submarine's design still retained its vulnerabilities to enemy fire that could spell assured death for all the crew.
The Type VIIC/42 was contracted for a total of 164 but were eventually given up in favor of the improved and all-new design of the Type XXI. These would have seen a stronger hull and an increase in torpedo-carrying capability.
The Type VIID was produced in six examples (all being lost by war's end) and featured vertical launching tubes for mine dispersal (a fore-runner to modern-day ballistic submarines). This group encompassed U-213 through U-218.
The Type VIIF became the heaviest of the entire Type VII class, produced as torpedo carriers and noted by not having any deck armament. A total of 39 torpedoes could be carried and designations covered U-1059 through U-1062.
At any rate, the Type VII was indeed the cream of the U-boat class - sheer numbers dictated that fact but so did performance and the fear they inflicted on sailors and captains alike. The scourge of the U-boat would have not been so without the Type VII commanding the waters between England and the United States, giving Germany an edge for at least a while - that is until tactics and technology changed in the favor of the Allies. The Type VII would see aggressive combat against Allied shipping and warships through to the end of the war, solidifying its place in naval history. Along with its legacy, u-boat design ushered in a new age of submarines that would dominate the oceans of the world throughout the Cold War and beyond.