The Bayern class was a class of four super-dreadnought battleships built by the German Kaiserliche Marine. The class comprised Bayern, Baden, Sachsen, and Württemberg. Construction started on the ships shortly before World War I; Baden was laid down in 1913, Bayern and Sachsen followed in 1914, and Württemberg, the final ship, was laid down in 1915. Only Baden and Bayern were completed, due to shipbuilding priorities changing as the war dragged on. It was determined that U-boats were more valuable to the war effort, and so work on new battleships was slowed and ultimately stopped altogether. As a result, Bayern and Baden were the last German battleships completed by the Kaiserliche Marine.
The Mackensen class was the last class of battlecruisers to be built by Germany in World War I. The design initially called for seven ships, but three of them were redesigned as the Ersatz Yorck class. Of the four ships of the Mackensen class, Mackensen, Graf Spee, and Prinz Eitel Friedrich were launched, and Fürst Bismarck was not—but none were completed, after wartime shipbuilding priorities were redirected towards U-boats—and the ships were broken up in the early 1920s. The lead ship of the class was named for August von Mackensen, a prominent military commander during the war. In response to the Mackensen-class ships, the British Royal Navy laid down the Admiral-class battlecruisers, all but one of which would eventually be cancelled; the sole survivor, HMS Hood, was completed after the end of the war.
The Königsberg class, sometimes referred to as the K class, was a class of light cruisers of the German Reichsmarine and Kriegsmarine. The class comprised three ships named after German cities: Königsberg, Karlsruhe, and Köln, all built between 1926 and 1930. These ships were the first of the Reichsmarine with a modern cruiser design; their predecessor, Emden, was based on World War I-era designs. They were armed with a main battery of nine 15 cm (5.9 in) guns and with twelve 50 cm (20 in) torpedo tubes.
The Admiral Hipper class was a group of five heavy cruisers built by Nazi Germany's Kriegsmarine beginning in the mid-1930s. The class comprised Admiral Hipper, the lead ship, Blücher, Prinz Eugen, Seydlitz, and Lützow. Only the first three ships of the class saw action with the German Navy during World War II. Work on Seydlitz stopped when she was approximately 95 percent complete; it was decided to convert her into an aircraft carrier, but this was not completed either. Lützow was sold incomplete to the Soviet Union in 1940.
The Leipzig class was a class of two light cruisers of the German Reichsmarine and later Kriegsmarine; the class comprised Leipzig, the lead ship, and Nürnberg, which was built to a slightly modified design. The ships were improvements over the preceding Königsberg-class cruisers, being slightly larger, with a more efficient arrangement of the main battery and improved armor protection. Leipzig was built between 1928 and 1931, and Nürnberg followed between 1934 and 1935.
The O class was a planned class of three battlecruisers for the Kriegsmarine before World War II. Prompted by a perceived lack in ship numbers when compared with the British Royal Navy, the O class' design was born with the suggestion of modifying the P-class cruiser design with 380 mm (15 in) guns instead of 283 mm (11.1 in).
The P class was a planned group of twelve heavy cruisers of Nazi Germany's Kriegsmarine; they were the successor to the Deutschland-class cruisers. Design work began in 1937 and continued until 1939; at least twenty designs were submitted with nine of them being considered. There were three designs that were selected as the final contenders. One design was armed with six 283mm main guns in one triple turret forward and one more turret aft. It had two 150mm double secondary gun turrets as secondary armament with one being positioned above and just fore of the aft of the main 283mm main turret, and the other being in front and lower of the front main gun turret. This design had more beam than the other 2 designs. It also mounted 2 seaplanes on its fantail instead of the mid ship area. The final design was armed with six 28 cm (11 in) quick-firing guns in two triple turrets, as in the preceding Deutschland class. The ships were designated as Panzerschiff, and given the preliminary names P1–P12. They were an improved design over the preceding planned D-class cruisers, which had been canceled in 1934. Although the ships were already assigned to shipyards, construction never began on the P-class ships after the O-class battlecruiser design superseded them.
The Derfflinger class was a class of three battlecruisers of the Imperial German Navy. The ships were ordered for the 1912–13 Naval Building Program of the German Imperial Navy as a reply to the Royal Navy's two new Lion-class battlecruisers that had been launched a few years earlier. The preceding Moltke class and the incrementally improved Seydlitz represented the end of the evolution of Germany's first generation of battlecruisers. The Derfflinger class had considerable improvements, including a larger primary armament, all of which was mounted on the centerline. The ships were also larger than the preceding classes. The Derfflinger class used a similar propulsion system, and as a result of the increased displacement were slightly slower.
The Roon class was a pair of armored cruisers built for the German Kaiserliche Marine in the 1900s. The two ships of the class, Roon and Yorck, closely resembled the earlier Prinz Adalbert-class cruisers upon which they were based. The Roon class incorporated slight incremental improvements, including a pair of extra boilers. The ships were easily distinguished from their predecessors by the addition of a fourth funnel. Though the additional boilers were meant to increase the ships' speed, both vessels failed to reach their designed top speed. In addition, the ships had comparatively light armament and thin armor protection, so they compared poorly with their foreign contemporaries, particularly the armored cruisers of their primary opponent, the British Royal Navy.
The Prinz Adalbert class was a group of two armored cruisers built for the German Kaiserliche Marine under the terms of the Second Naval Law. Two ships of the class were built, Prinz Adalbert and Friedrich Carl, between 1900 and 1904. The two ships were heavily based on the previous armored cruiser, Prinz Heinrich, with a series of incremental improvements. Their armor layout was revised slightly to improve internal protection and their main battery consisted of four 21 cm (8.3 in) guns instead of the two 24 cm (9.4 in) carried by Prinz Heinrich. The new ships also received more powerful propulsion systems, making them slightly faster. Prinz Adalbert spent her peacetime career as a gunnery training ship while Friedrich Carl initially served as the flagship of the fleet's reconnaissance forces. By 1909, she had been replaced by more modern cruisers and joined Prinz Adalbert as a training vessel.
The Scharnhorst class was the last class of traditional armored cruisers built by the German Kaiserliche Marine. The class comprised two ships, Scharnhorst and Gneisenau. They were larger than the Roon-class cruisers that preceded them; the extra size was used primarily to increase the main armament of 21 cm (8.2 inch) guns from four to eight. The ships were the first German cruisers to reach equality with their British counterparts. The ships were named after 19th century Prussian army reformers, Gerhard von Scharnhorst and August von Gneisenau.
The Wiesbaden class of light cruisers was a class of ships built by the German Kaiserliche Marine shortly before the outbreak of World War I. Two ships were built in this class, Wiesbaden and Frankfurt. They were very similar to the preceding design, the Graudenz class, though they were armed with eight 15 cm SK L/45 guns instead of the twelve 10.5 cm SK L/45 guns on the earlier vessels. The ships had a top speed of 27.5 knots.
The Brummer class consisted of two light mine-laying cruisers built for the Imperial German Navy in World War I: SMS Brummer and SMS Bremse. When the war broke out, the Germans had only two older mine-laying cruisers. Although most German cruisers were fitted for mine-laying, a need for fast specialized ships existed. The Imperial Russian Navy had ordered sets of steam turbines for the first two ships of the Svetlana-class cruisers from the AG Vulcan shipyard in Stettin. This machinery was confiscated on the outbreak of war and used for these ships. Both vessels were built by AG Vulcan.
The Königsberg class was a group of four light cruisers built for the German Imperial Navy. The class comprised four vessels: SMS Königsberg, the lead ship, SMS Nürnberg, SMS Stuttgart, and SMS Stettin. The ships were an improvement on the preceding Bremen class, being slightly larger and faster, and mounting the same armament of ten 10.5 cm SK L/40 guns and two 45 cm (17.7 in) torpedo tubes.
The Ersatz Yorck class was a group of three battlecruisers ordered but not completed for the German Kaiserliche Marine in 1916. The three ships had originally been ordered as additions to the Mackensen class, but developments abroad, particularly the British Renown-class battlecruisers, led to the navy re-designing the ships. The primary change was an increase of the main battery from eight 35-centimeter (14 in) guns to eight 38 cm (15 in) weapons. Work on the first ship had already begun by the time the navy decided to re-design the ships, so the design staff was constrained by the need to use the material already assembled.
The Königsberg class of light cruisers was a group of four ships commissioned into Germany's Kaiserliche Marine shortly before the end of World War I. The class comprised Königsberg, Karlsruhe, Emden, and Nürnberg, all of which were named after light cruisers lost earlier in the war. The ships were an incremental improvement over the preceding Wiesbaden-class cruisers, and were armed with a main battery of eight 15 cm (5.9 in) SK L/45 guns and had a designed speed of 27.5 knots.
The Karlsruhe class of light cruisers was a pair of two ships built for the German Imperial Navy before the start of World War I. The ships—SMS Karlsruhe and Rostock—were very similar to the previous Magdeburg-class cruisers, mounting the same armament and similar armor protection, though they were larger and faster than the earlier ships. Both vessels were laid down in 1911, and launched one day apart, on 11 and 12 November 1912. Karlsruhe joined the fleet in January 1914, but fitting out work lasted slightly longer on her sister; Rostock was commissioned the following month.
L 20e α was a design for a class of battleships to be built in 1918 for the German Kaiserliche Marine during World War I. Design work on the class of battleship to succeed the Bayern-class battleships began in 1914, but the outbreak of World War I in July 1914 led to these plans being shelved. Work resumed in early 1916 and lessons from the Battle of Jutland, fought later that year, were incorporated into the design. Reinhard Scheer, the commander of the fleet, wanted larger main guns and a higher top speed than earlier vessels, to combat the latest ships in the British Royal Navy. A variety of proposals were submitted, with armament ranging from the same eight 38 cm (15 in) guns of the Bayern class to eight 42 cm (16.5 in) guns.
The D-class cruisers were a pair of German heavy cruisers, classified as panzerschiffe by the Reichsmarine. The ships were improved versions of the preceding Deutschland-class cruisers, authorized by Adolf Hitler in 1933. They were intended to counter a new French naval construction program. Displacement increased to 20,000 long tons (20,000 t), 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 Dunkerque-class battleship. The construction contracts for both ships were superseded by the Scharnhorst-class battleships.
The H class was a series of battleship designs for Nazi Germany's Kriegsmarine, which were intended to fulfill the requirements of Plan Z in the late 1930s and early 1940s. The first variation, "H-39," called for six ships to be built, essentially as enlarged Bismarck-class battleships with 40.6 cm (16 in) guns and diesel propulsion. The "H-41" design improved the "H-39" ship with still larger main guns, eight 42 cm (16.5 in) weapons, and reinforced deck armor. The Construction Office of the Oberkommando der Marine (OKM) concluded their work with the "H-41" design, and were not involved in subsequent plans. Two of them, "H-42" and "H-43", increased the main battery yet again, with 48 cm (18.9 in) pieces, and the enormous "H-44" design ultimately resulted with 50.8 cm (20 in) guns. The ships ranged in size from the "H-39", which was 277.8 m long on a displacement of 56,444 t, to the "H-44", at 345 m on a displacement of 131,000 t. Most of the designs had a proposed top speed in excess of 30 knots (56 km/h).
Kriegsmarine 
