L 20e α-class battleship

Class overview
Name	L 20 α class
Operators	Kaiserliche Marine
Preceded by	Bayern class
Succeeded by	None
Planned	Unknown
Completed	None
General characteristics
Type	Battleship
Displacement	Normal: 43,800 t (43,100 long tons; 48,300 short tons) Full load: 48,700 t (47,900 long tons; 53,700 short tons)
Length	238 m (781 ft)
Beam	33.5 m (110 ft)
Draft	Normal: 9 m (29 ft 6 in) Full load: 9.9 m (32 ft 6 in)
Installed power	100,000 shaft horsepower (75,000 kW)
Propulsion	2 or 4 shafts, 2 or 4 steam turbines 22 Schulz-Thornycroft boilers
Speed	26 kn (48 km/h; 30 mph)
Armament	8 × 42 cm (16.5 in) SK L/45 guns 12 × 15 cm (5.9 in) SK L/45 guns 8 × 8.8 cm (3.45 in) or 10.5 cm (4.1 in) Flak L/45 guns 3 × 60 cm (23.6 in) or 70 cm (27.6 in) torpedo tubes
Armor	Belt: 130 to 350 mm (5.1 to 13.8 in) Bulkheads: 60 to 250 mm (2.4 to 9.8 in) Battery: 170 mm Barbettes: 100 to 350 mm (3.9 to 13.8 in) Turrets: 150 to 350 mm (5.9 to 13.8 in) Conning Tower: 150–350 mm

L 20 α was a design plan for a class of battleships to be built in 1918 for the Kaiserliche Marine during World War I. The design was selected on 2 October 1917, and construction was to have started 11 September 1918. The ships would have been significantly larger than the preceding Bayern class battleships, at 238 m (781 ft) long, compared to 180 m (590 ft) for the preceding ships. The ships would have been the first German warship to have mounted guns larger than 40.6 cm (16 in). However, Germany's declining war situation and the transfer of emphasis within the Navy from capital ships to submarines meant that the ships would never be constructed.

Design

In January 1916, Vice Admiral Reinhard Scheer became commander in chief of the High Seas Fleet. Following the Battle of Jutland on 31 May – 1 June 1916, Scheer pushed for new, more powerful battleships. He demanded the new ships have guns of 42 cm (16.5 in) caliber, an armored belt 350 mm (14 in) thick, and be capable of speeds of up to 32 knots (59 km/h; 37 mph), all on a displacement of up to 50,000 metric tons (49,000 long tons; 55,000 short tons).

During the design process, it was decided that the utmost concern was that the ships could be built quickly and placed into service. The ships were to discard the use of broadside belt armor below the waterline, the attachment of which was an extremely long process. It was believed that the higher speed of the class—26 knots (48 km/h; 30 mph)—would make up for the vulnerability to torpedo attack and make the armor unnecessary. The initial designs called for three main battery turrets, each mounting a pair of new 42 cm (16.5 inch) guns, though this was later increased to four twin turrets. However, the work that would have been necessary to design and test the new turret clashed with U-boat construction, which had become the priority of the Navy. Krupp, the firm that had been awarded the contract to conduct the testing, informed the Reichsmarineamt (RMA— the Imperial Navy Office) that design work on the new turret would have to wait. Admiral von Capelle accepted the news without much objection. The RMA filed a report dated 1 February 1918, which stated that capital ship construction had ground to a halt, primarily due to the shifting priorities to the U-boat war.

Armament

The main battery was arranged in four twin turrets, as in the preceding Bayern class, in a superfiring arrangement on the centerline. The aft pair of turrets were separated by engine rooms. The four turrets mounted two 42 cm (16.5 in) SK L/45 guns, for a total of eight guns on the broadside. The ships were to have been armed with a secondary battery of twelve 15 cm (5.9 in) guns mounted in casemates. The anti-aircraft battery was to have consisted of either eight 8.8 cm (3.45 in) Flak L/45 guns or eight 10.5 cm (4.1 in) Flak L/45 guns. The design was to have been equipped with three submerged torpedo tubes, either 60 cm (23.6 cm) or 70 cm (27.6 in) in diameter. One tube was placed in the bow, the other two on either beam to the rear of the engine rooms.

Armor

The ships had a 350 mm (14 in) armored belt, and ran from slightly forward of the fore barbette to slightly aft of the fourth barbette. The belt began 35 cm below the waterline to 195 cm (77 in) above it. The barbettes were also 350 mm thick on the front and sides, but decreased to 250 mm (9.8 in) on the rear. The main gun turrets had 350 mm faces, 250 mm sides, 305 mm (12.0 in) rears, and 150 to 250 mm (5.9 to 9.8 in) roofs. The ships' armored deck was to have been 50 mm (2.0 in) thick forward, increased to 50 to 60 mm (2.0 to 2.4 in) amidships, and 50 to 120 mm (2.0 to 4.7 in) aft. The ships were also to have had a forecastle deck that was 20 to 40 mm (0.79 to 1.57 in) thick. The ships were also protected by a torpedo bulkhead that was 50–60 mm thick. A sloped 30 mm (1.2 in) thick splinter bulkhead, designed to protect against shell fragments, extended from the top of the torpedo bulkhead up to the upper deck.

Machinery and other characteristics

The ships were to have been powered by 6 oil-fired and 16 coal-fired boilers, and either 2 or 4 sets of steam turbines. The design was to have a single funnel trunked from the engine rooms. The ships would have stored 2,950 metric tons (2,900 long tons; 3,250 short tons) of coal and 1,970 metric tons (1,940 long tons; 2,170 short tons) of fuel oil. The ships were intended to have a single tripod foremast, as was typical for German battleships of the period.

References

• Gardiner, Robert; Gray, Randal, eds. (1984). Conway's All the World's Fighting Ships: 1906-1922. Annapolis: Naval Institute Press. ISBN 0870219073.
• Herwig, Holger (1980). "Luxury" Fleet: The Imperial German Navy 1888-1918. Amherst, New York: Humanity Books. ISBN 9781573922869.
• Weir, Gary (1992). Building the Kaiser's Navy. Annapolis: Naval Institute Press. ISBN 1557509298.