Design work on the class began in 1892 and lasted until 1894. The ships of the Kaiser Friedrich III class marked a significant departure from the previous Brandenburg-class battleships. Influenced by the Japanese cruisers' victory over a heavier-armed Chinese fleet at the Battle of Yalu, heavy-caliber guns designed to penetrate armor were abandoned and replaced with smaller quick-firing guns. These guns were intended to raze the superstructure of enemy battleships and demoralize the crew. The propulsion system was improved and reorganized to incorporate a third propeller shaft. The armor system, however, remained similar to that employed on the Brandenburgs.
Line-drawing of the Kaiser Friedrich III
The Kaiser Friedrich III-class ships were 120.9 meters (396 ft 8 in) long at the waterline and 125.3 m (411 ft 1 in) overall. They had a beam of 20.4 m (66 ft 11 in) and a draft of 7.89 m (25 ft 11 in) forward and 8.25 m (27 ft 1 in) aft. The ships displaced 11,785 metric tons (11,599 long tons) at full load. Transverse and longitudinal steel frames were used to build the hulls for the Kaiser Friedrich III-class ships. Steel hull plates were riveted to the frame. The hull contained twelve watertight compartments and a double bottom that ran for 70 percent of the hull.
The German navy regarded them as excellent sea vessels. They had a tight turning circle and were very responsive. The ships rolled up to 15° and had a roll period of 12 seconds. They suffered only minor speed loss in heavy seas, but up to 40 percent with the rudder hard over. Their metacentric height was between .917 to 1.18 m (3 ft 0.1 in to 3 ft 10.5 in). The ships carried a number of smaller boats, including two picket boats, two launches, one pinnace, two cutters, two yawls, and two dinghies. The crew numbered 39 officers and 612 enlisted men. When serving as a squadron flagship, a ship had its crew augmented by another 12 officers and between 51 to 63 enlisted men.
The Kaiser Friedrich III-class battleships were powered by three 3-cylinder vertical triple expansion engines that drove three screws. Kaiser Friedrich III, Kaiser Barbarossa, and Kaiser Wilhelm der Grosse were equipped with three 3-bladed screws that were 4.5 m (14 ft 9 in) in diameter. Kaiser Karl der Grosse and Kaiser Wilhelm II were equipped with two of the 3-bladed screws on the outer shafts and a four-bladed screw that was 4.2 m (13 ft 9 in) in diameter on the center shaft. Kaiser Friedrich III had four Thornycroft and eight cylindrical boilers; Kaiser Wilhelm II had a similar arrangement, except the Thornycroft boilers were replaced by Marine-type boilers. Kaiser Wilhelm der Grosse was equipped with four Marine and six cylindrical boilers, while Kaiser Barbarossa had four Thornycroft and six cylindrical boilers. Kaiser Karl der Grosse had two Marine boilers, two Marine double boilers, and six cylindrical boilers.
The powerplants were rated at 13,000 metric horsepower (12,822 ihp; 9,561 kW), but on trials could produce up to 13,950 PS (13,760 ihp; 10,260 kW). This generated a top speed of 17.5 knots (32.4 km/h; 20.1 mph). The ships carried 650 metric tons (640 long tons; 720 short tons) of coal, although the use of additional spaces within the ships increased fuel capacity to 1,070 metric tons (1,050 long tons; 1,180 short tons). This provided a maximum range of 3,420 nautical miles (6,330 km; 3,940 mi) at a cruising speed of 10 knots (19 km/h; 12 mph). Electrical power was supplied by five 320 kW 74 Volt generators in Kaiser Friedrich III and Kaiser Wilhelm II, and four 240 kW 74 V generators in the other three ships.
The ships' armament consisted of a main battery of four 24 cm (9.4 in) SK L/40 guns in twin gun turrets,[a] one fore and one aft of the central superstructure. The guns were mounted in Drh.L. C/98 turrets, which allowed elevation to 30° and depression to −5°. At maximum elevation, the guns could hit targets out to 16,900 meters (18,500 yd). The guns fired 140-kilogram (310 lb) shells at a muzzle velocity of 690 m/s (2,263 ft/s). They had a rate of fire of three to four shots per minute. Each gun was supplied with 75 shells, for a total of 300.
Secondary armament included eighteen 15 cm (5.9 inch) SK L/40 guns; six were emplaced in single turrets amidships and twelve were mounted in MPL casemates.[b] These guns fired armor-piercing shells at a rate of 4–5 per minute. The ships carried 120 shells per gun, for a total of 2,160 rounds total. The guns could depress to −7 degrees and elevate to 20 degrees, for a maximum range of 13,700 m (14,990 yd). They were manually elevated and trained.
The ships also carried twelve 8.8 cm (3.45 in) SK L/30 quick-firing guns, also mounted in casemates. These guns were supplied with between 170 and 250 shells per gun. These guns fired 13.8 kg (30.4 lb) at a muzzle velocity of 590 m/s (1,936 ft/s). Their rate of fire was approximately 15 shells per minute; the guns could engage targets out to 10,500 m (11,480 yd). The gun mounts were manually operated. The ships' gun armament was rounded out by twelve machine guns.
The ships were also armed with six 45 cm torpedo tubes, all in above-water swivel mounts. Four tubes were mounted on the sides of the ship, another in the bow, and the last in the stern. These weapons were 5.1 m (16 ft 9 in) long and carried an 87.5 kg (193 lb) TNT warhead. They could be set at two speeds for different ranges. At 26 knots (48 km/h; 30 mph), the torpedoes had a range of 800 m (870 yd). At an increased speed of 32 knots (59 km/h; 37 mph), the range was reduced to 500 m (550 yb).
The Kaiser Friedrich III-class ships were armored with steel produced by Krupp. They had an armor belt that was 300 millimeters (12 in) thick in the central portion of the hull at the waterline. It tapered to 150 mm (5.9 in) in the forward section and 200 mm (7.9 in) in the rear, although the belt did not extend fully aft. The lower portion of the belt ranged in thickness from 100 to 180 mm (3.9 to 7.1 in). The entire belt was backed with 250 mm (9.8 in) of teak. The armored deck was 65 mm (2.6 in) thick.
The conning tower was protected by armored sides that were 250 mm thick and a roof that was 30 mm (1.2 in) thick. Each main-battery turret had a 50 mm (2.0 in) thick roof and 250 mm thick sides. The 15 cm guns mounted in turrets were protected by 150 mm thick sides and 70 mm (2.8 in) thick gun shields. Those in the casemates also had 150 mm worth of armor protection.