Seydlitz was a heavy cruiser of the German Kriegsmarine, fourth in the Admiral Hipper class, but was never completed. The ship was laid down in December 1936 and launched in January 1939, but the outbreak of World War II interrupted her completion at approximately 90 percent. The unfinished ship remained inactive until March 1942, when the Kriegsmarine decided to pursue aircraft carriers over surface combatants. Seydlitz was among the vessels chosen for conversion into auxiliary aircraft carriers.
Renamed Weser, the ship was to have had a complement of ten Bf 109 fighters and ten Ju 87 divebombers. Work was not completed, however, and the incomplete vessel was towed to Königsberg where she was eventually scuttled.
General characteristics (as cruiser)
Class and type: Admiral Hipper-class cruiser
Displacement: Design: 17,600 t (17,300 long tons; 19,400 short tons)
Full load: 19,800 long tons (20,100 t)
Length: 210 m (689 ft 0 in) overall
Beam: 21.8 m (71 ft 6 in)
Draft: Full load: 7.9 m (26 ft)
Propulsion: 3 × Blohm & Voss steam turbines
3 × three-blade propellers
100,000 hp (75 MW)
Speed: 32 knots (59 km/h; 37 mph)
Complement: 42 officers
1,340
Armament: 8 × 20.3 cm (8.0 in) guns
12 × 10.5 cm (4.1 in) guns
12 × 3.7 cm (1.5 in) guns
8 × 2 cm (0.79 in) guns (20×1)
6 × 53.3 cm (21 in) torpedo tubes
Armor: Belt: 70 to 80 mm (2.8 to 3.1 in)
Armor deck: 20 to 50 mm (0.79 to 2.0 in)
Turret faces: 105 mm (4.1 in)
Aircraft carried: 3 aircraft
Aviation facilities: 1 catapult
General characteristics (as aircraft carrier)
Displacement: Design: 17,139 t (16,868 long tons; 18,893 short tons)
Length: 216 m (708 ft 8 in) overall
Draft: Full load: 6.65 m (21.8 ft)
Armament: 10 × 10.5 cm guns
10 × 3.7 cm guns
24 × 2 cm guns
Aircraft carried: 20 aircraft,