Double hull boat

Than Double hull boat is called U-boats , which were designed for a specific ship design and manufacturing. envelope Two boats were mainly in the First and the Second World War in action. After the end of World War II, they were gradually replaced by Einhüllenboote with a hydrodynamically optimized hull form replaced. One exception, however, most Russian nuclear submarines.

Until the mid-19th Century, the first underwater vehicles have been built as Einhüllenboote, but this was mainly due to the lack of technical possibilities. It was only towards the middle / end of the 19th Century did the developers, the propeller and the rudder depth of submarines so the fuselage to mount that the vehicles could be moved independently and controlled, without being held to the surface of a support vehicle. These technical innovations brought some benefits to the submarine construction with him. So now the construction of the shells have been strengthened by increased metal inserts, until finally in the early 20th Century managed to build the first submarines of a complete steel hull, such as the boats of trout -class show. The benefits of these boats were quickly apparent, as they were particularly improved seaworthiness visible at surface running, and also offered a much higher stability of the hull and the pressure hull shell . Since the 20th of the first submarines Century, primarily through water and only drove for aggressive purposes or to flee toWarlords went to these boats had also another claim in the design and construction are provided. To the U-boats thus "seaworthy" to make, they were changed constructionally and result were the so-called " two-shell boats . "

Two shell boats are characterized in that at the cylindrical shaped submarine pressure body of metal, the first Sheath diving cells as second Casing were wrapped. This has the particular advantage that thereby gained more space in the proper pressure hull for crew, controls and weapons because "Evacuate" immersion tanks could. In addition to that so now one for the surface running more suitable external configuration was enabled. Since the so-called second Case in immersion condition inside and out was under the same pressure needed, this also not to be particularly strong, increasing the weight of the submarine has not increased significantly. The changes in weight due to fuel consumption is compensated by also located outside the pressure hull, semi-open-bunker fuel oil into the sea water could flow in.
With the increasing towards the end of World War II technical development gradually disappeared after the water aspect of submarines and was therefore again less demands on the stability of a corresponding body. So the received two-shell boat initially a hydrodynamically clean, smooth shape, and American developments in the experimental submarine USS Albacore eventually led to today mostly built teardrop.

Russian subs

Many Russian nuclear submarines such as the Akula class , Sierra class and Oscar class are Zweihüllenbote, the distance between the first shell and the actual printing body can be several meters, depending on the class. The reason for this design feature is the better protection against explosions (ie, torpedoes , depth charges), so most ships can not be sunk with a warhead weight below 50 kg.