D-class cruiser (Germany)

D-class cruiser (Germany)
The D-class cruisers were a pair of German heavy cruisers, classified as ("armored ships") by the (Navy of the Realm). The ships were improved versions of the preceding s, authorized by Adolf Hitler in 1933. They were intended to counter a new French naval construction program. Displacement increased to , but Hitler allowed only increases to armor, prohibiting additions to the ships' main battery armament. Only one of the two ships was laid down, but work was canceled less than five months after the keel was laid. It was determined that the designs should be enlarged to counter the new French . The construction contracts for both ships were superseded by the s.
Design
The ships were designed as follow-ons to the s. In 1933, the rise of the Nazi Party brought Adolf Hitler to power in Germany. At the time, he opposed a large-scale naval rearmament program, but decided to allow limited construction to counter French naval expansion. He therefore authorized the (Navy of the Realm) to build two additional (armored ships) to supplement the three s. He stipulated that displacement be limited to and the primary battery would remain two triple gun turrets mounting guns. Admiral Erich Raeder, the commander in chief of the , advocated increasing the armor protection for the new and inquired about the possibility of including a third triple turret. It was determined, however, that a third turret could not be added to the ship and still remain within the 19,000 ton limit prescribed by Hitler.
The ships were designed under the contract names D and E, and designed under the provisional names and as replacements for the old pre-dreadnought battleships and . The contract for the first ship, D, was awarded on 25 January 1934 to the in Wilhelmshaven. The ship's keel was laid on 14 February. That month, the decided to alter the designs to counter the new s building in France. Displacement was increased to and a third 28 cm triple-turret was added. Construction on D was therefore halted on 5 July, and E was never laid down. The construction contracts were canceled and reallocated for the two battleships of the .
Characteristics
The ships were long overall, and at the waterline. The ships would have had a beam of and a draft of . The finalized design displaced at the designed displacement. "D" was to have been fitted with accommodations to serve as a fleet flagship. The ships would have been turbine-powered; the engines were designed to provide and a top speed of . The number of and type of boilers for the turbines is unknown, but they would have been vented through two large funnels.
The ships would have been similarly equipped to the preceding -class ships. The ships would have mounted a main battery of six of the same /52 C/28 quick-firing guns in the same triple turret mounts, though eight guns were considered, had there been a quadruple turret available. The guns had an actual bore diameter of , and fired both armor-piercing and high-explosive shells; both shells weighed 300 kg (661.4 lb). The guns used two sets of propellant charges: a 36.0 kg (79.4 lb) fore charge in a silk bag and a 71.0 kg (156.6 lb) main charge in a brass case. The shells were fired at 910 meters per second (2,986 fps), and at maximum elevation of 40 degrees, a range of 36,475 m (39,890 yards). The guns had a rate of fire of 2.5 rounds per minute. The guns were supplied by a total of 900 shells, for a total of 150 rounds per gun.
The design's secondary battery comprised eight /55 SK C/28 quick-firing guns in four twin turrets, two abreast the conning tower and the other pair abreast the rear funnel. The guns fired a shells at a muzzle velocity of . With a maximum elevation of 40°, the guns could fire out to . These guns had already been ordered by the time construction of the ships was canceled; their availability influenced the design of the class, which mounted eight of their twelve 15 cm guns in dual turrets.
The heavy anti-aircraft battery consisted of eight SK C/33 guns in twin mountings. The mounts were the Dopp LC/31 type, originally designed for earlier SK C/31 guns. The LC/31 mounting was triaxially stabilized and capable of elevating to 80°. This enabled the guns to engage targets up to a ceiling of . Against surface targets, the guns had a maximum range of . The guns fired fixed ammunition weighing ; the guns could fire HE and HE incendiary rounds, as well as illumination shells. A number of various other anti-aircraft guns were also to be fitted, but the details were not determined before the class was canceled. The ships were also armed with an unknown number of torpedo tubes.
The D-class ships used steel manufactured by Krupp for their armor. The ships' upper deck armor was thick. The main armored deck was forward, amidships, and decreased to 70 mm towards the stern. The conning tower was quite heavily armored, with side armor thick. The main armored belt was thick, and the upper citadel armor was thick.
Footnotes
References
Cruisers of the Reichsmarine
Proposed ships of Germany