The Type VII U-boats were German submarines whose construction was initiated in 1936. The length of the Type VII units, depending on the sub-type, ranged from 64.5 m to 77.6 m, width from 5.85 m to 7.3 m, and the underwater displacement - from 725 tons to 1181 tons. The maximum surface speed of the Type VII U-boats was approximately 17 knots, and the maximum underwater speed was approximately 8 knots. The main armament was 5 533 mm torpedo tubes with a total of 11-16 torpedoes carried on board the ship. The secondary armament consists of 1 88mm cannon, 1 20mm anti-aircraft cannon or 1 37mm cannon, and 2 duplicate 20mm cannons on the VII D and VII F.
The Type VII U-boats were the staple of the German weapon in the Battle of the Atlantic and created the series of the most produced submarines in naval history! Several subtypes of this class of ships were created in the course of serial production. Chronologically, the first was the Type VII A, which was created on the basis of the Type III U-boot that dates back to the roots of the First World War. Initially, it had only 4 torpedo tubes, but its design features were very good - for example, it could be submerged very quickly. Another type was the Type VII B, which carried more spare torpedoes and had a smaller turning radius under water. It also had a changed rudder system. The most frequently produced was the Type VII C, which was equipped with active sonar, but also had a greater maximum depth of immersion and in the first versions of this sub-type - a significantly increased range (on the surface up to about 16,300 km). The next version was the Type VII D, which acted as an underwater mine ship. The last one entered service was the Type VII F, which was designed as an underwater torpedo carrier by adding a special section behind the conning tower. However, due to the changes in the realities of combat in the Atlantic and the shortening of the patrol range of other U-boats, the Type VII F was used as an underwater transport. In the period from 1936 to 1945, about 700 submarines of this type were built.