Königsmarck-class Battlecruiser
 KMS Königsmarck in 1914
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| Class overview | |
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| Name: | Königsmarck class |
| Builders: | Isenstadt Naval Works |
| Operators: | Arcaenian Königsmarine |
| Built: | 1909-1913 |
| Planned: | 3 |
| Completed: | 3 |
| General characteristics (as built) | |
| Type: | Battlecruiser |
| Displacement: |
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| Length: | 200 m |
| Beam: | 28.5 m |
| Draft: | 9.3 m |
| Installed power: |
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| Propulsion: |
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| Speed: | 28 knots |
| Range: | 4,200 nautical miles (7,800 km) at 14 knots (26 km/h) |
| Complement: | 1,100 |
| Armament: |
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| Armor: |
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Design
General characteristics
The Königsmarck-class ships had an overall length of 200 meters, a beam of 28.5 meters, and a draft of 9.3 meters at full load. They displaced 24,900 tonnes at normal load and 28,500 tonnes at full load. The ships had a double bottom which ran for 75% of the length of the hull. The hull was constructed from longitudinal steel frames made of mild steel with riveted on outer hull plates and was divided longitudinally into 17 watertight compartments.
Propulsion
The Königsmarck-class ships were equipped with two sets of steam turbines with two high pressure turbines and two low pressure turbines each driving a three bladed propeller that was 3.90 meters in diameter. The high pressure turbines directly drove the outer two propeller shafts while the low pressure turbines directly drove the inner two propeller shafts. Steam for the turbines was provided by twenty-eight small-tube coal-fired boilers that had two fire boxes per boiler. The boilers were divided into three boiler rooms with the exhausts directed into a pair of funnels. The engines were designed to produce 64,000 shp (48,000 kW) at 290 RPM and give the ships a top speed of 26.5 knots. Using forced draft on trials the engines provided up to 89,000 shp (66,000 kW) of power with a resulting top speed of 28 knots. The ships carried up to 3,600 tonnes of coal which gave the ships a maximum range of 4,200 nautical miles (7,800 km) at a cruising speed of 14 knots (26 km/h). Electrical power was provided by a pair of turbo generators and a pair of diesel generators that provided 1,800 kW at 220 V. Each ship was equipped with two rudders mounted side-by-side behind the inner two propeller shafts.
Armament
Main battery
The primary armament of the Königsmarck-class battleships consisted of four 30.5 cm SK L/50 guns mounted in four two-gun turrets in two superfiring pairs along the centerline, one pair forward and one pair aft with the aft turrets separated by the ship's engine rooms. The guns were designed to fire 405 kg (893 lb) kg projectiles at a muzzle velocity of [convert: invalid number] out to a maximum range of 23,200 m (25,400 yd) at an elevation of 20 degrees. The Psgr. L/3.4 armor piercing shell had a length of 3.4 calibers and was fitted with a hard armor piecing cap and contained an 11.5kilogram TNT bursting charge. The Spgr. L/3.8 high explosive shell had a length of 3.8 calibers and contained a 26.5 kilogram TNT bursting charge and was fitted with a base mounted fuze that would detonate 3 to 6 meters behind the point of impact when impacting unarmored or lightly armored parts of a ship. Armor piecing shells were painted blue while high explosive shells were painted yellow. Total ammunition stowage was 720 rounds or 90 rounds per gun with the typical shell allotment being 65 AP rounds and 35 HE rounds per gun. Rate of fire was around 2-3 rounds per minute per gun. The guns used a horizontal sliding wedge breech block with the propellant charge consisted of a 34.5 kg (76 lb) fore charge contained in a silk bag and a 91 kg (201 lb) main charge contained in a brass case which sealed the breech of the gun. The gun turrets were trained and loaded with electric motors with elevation being hydraulically powered. The turrets were capable of traversing +150 / -150 degrees from centerline at a speed of 3 degrees per second and elevating from -5 to +20 degrees at a speed of 5 degrees per second. Hydraulic power for each turret was provided by two triple cylinder pumps driven by electric motor. The projectile rammers were hydraulically powered with fluid being supplied directly from the elevation pumps. The wedge breech mechanisms on each gun were hydraulically powered but could also be manually operated.
Secondary battery
The secondary battery of the ships consisted of twelve 15 cm (5.9 in) SK L/45 guns mounted in armored casemates mounted along the sides of the superstructure. The guns fired 45.3 kg (100 lb) shells at a muzzle velocity of 835 meters per second (2,740 ft/s) and were loaded with a 13.7 kg (30 lb) RPC propellant charge contained in a brass case. Each casemate had its own magazines and ammunition hoists which could supply up to 7 complete rounds per gun per minute. Each gun could depress to −7 degrees and elevate to 20 degrees with a maximum range of 13,500 m (14,800 yd) at 20 degrees elevation. Each ship was supplied with 1,920 rounds of 15 cm ammunition with 160 rounds per gun.
For defense against torpedo boats the ships were also equipped with eight 10.5 cm (4.1 in) SK L/45 guns in open mountings on the deck, four of them were located around the forward smokestack and four more around the C turret. The guns fired 17.4 kg (38 lb) shells at a muzzle velocity of 710 meters per second (2,300 ft/s) and were loaded with a 3.2 kg (7.1 lb) RPC propellant charge contained in a brass case. The guns could elevate from -10 to +30 degrees and has a maximum firing range of 12,700 m at 30 degrees elevation. Later in service these were replaced with high angle FlaK mountings which allowed elevation from -5 to +70 degrees with an AA ceiling of 8,200 meters and a maximum surface range of 15,100 meters at 45 degrees elevation.
Torpedo armament
As was typical for capital ships of the era the ships were armed with submerged torpedo tubes with one 50 cm (27.6") tube in the bow, and two 50 cm tubes on each broadside, and one 50 cm tube in the stern with a total of 11 torpedoes stored on board. The torpedoes were the G6D type which were 6 meters (20 ft) long and carried a 160 kg (350 lb) Hexanite warhead. The torpedoes used kerosene wet-heater engine and had a range of 8,400 m (9,200 yd) at a speed of 27 knots or 3,500 m (3,800 yd) at a speed of 35 knots.
Armor
The main armor belt of the ships was 300 mm (11.8 in) thick face hardened cemented armor mounted on 50 mm thick teak and ran from slightly forward of the forward main battery barbette to slightly aft of the rear main battery barbette and protected the central citadel of the ship containing the ammunition magazines and the machinery spaces. The main strake extended from 2 meters above above the waterline to 0.4 meters below it where it tapered to 150mm at its lower edge, ending 1.7 meters below the waterline. Directly above the main belt armor was a 230 mm (9.1 in) thick strake of armor plating extending up to the main deck which covered the sides of the hull above the main belt. Forward of the A turret the belt armor was stepped down to 120 mm (4.7 in) and then to 100 mm (3.9 in) ending in a 120 mm (4.7 in) thick transverse bulkhead located 16 meters from the bow with a 30 mm (1.2 in) thick splinter bulkhead extending from the bulkead all the way to the front of the bow. Aft of the D turret the belt stepped down to 100 mm (3.9 in) and ended in a transverse bulkhead 100 mm (3.9 in) located 4.6 meters from the stern. he main armor deck was 30 mm (1.2 in) thick over the central citadel with 50 mm (2.0 in) thick sloped sections on either side of the main armor deck extending down at a 30 degree angle to meet the lower edge of the belt armor. Aft of the central citadel the thickness of the armor deck increased to 80 mm (3.1 in) thick and which along with the aft extension of the main belt armor formed an armored raft designed to protect the steering gear of the ships. An additional a 30 mm (1.2 in) thick longitudinal splinter bulkhead extended from inboard edges of the sloped part of the armor deck up to the forecastle deck.
The main battery turrets had 250 mm (9.8 in) thick faces, 200 mm (7.9 in) thick sides, and 210 mm (8.3 in) thick rears to balance them while the turret roofs were 100 mm (4.1 in) thick. The main battery turret barbettes were 230 mm (9.1 in) above deck and 200 mm (7.9 in) below deck. The 15 cm casemate guns had 150 mm (5.9 in) thick armor plating for the casemates while the guns themselves had 80 mm (3.1 in) thick shields to protect the crews from shell splinters. The forward conning tower had 350 mm (13.8 in) thick sides and an 80 mm (3.1 in) thick roof while the aft conning tower had 200 mm (7.9 in) thick sides and an 50 mm (2.0 in) thick roof.