Mackensen - class battlecruiser The " Mackensen " class was the last class of battlecruiser s to be built by Germany in World War I . The class was to have comprised four ships : " Mackensen " , the name ship , " Graf Spee " , " Prinz Eitel Friedrich " , and " Fürst Bismarck " . None of the vessels were completed , as shipbuilding priorities were redirected towards U - boats . They were broken up in the early 1920s . The design of the " Mackensen " s was a much improved version of the previous . They featured a new , more powerful 35 cm ( 13 . 8 inch ) gun . The " Mackensen " - class ships featured more powerful engines that gave the ships a higher top speed and a significantly higher cruising range . The " Mackensen " design provided the basis for the subsequent , which incorporated even larger 38 cm ( 15 inch ) main - battery guns , as a response to the Royal Navy ' s s . These last three ships are referred to as the " Ersatz Yorck " class , as the first ship of the class was designed to replace the armored cruiser , which had struck German mines early in the war and sunk . However , very little construction progress was made on these later ships . In response to the " Mackensen " - class ships , the British laid down the s for the Royal Navy , all but one of which would eventually be canceled ; the sole survivor , , was completed after the end of the war . Design . The fourth and final Naval Law , passed in 1912 , governed the building program of the German navy during World War I . The Navy Office decided the Navy should construct one battleship and one battlecruiser every year between 1913 and 1917 , with an additional unit of both types in 1913 and 1916 . By February 1915 , the German High Command had realized that the war would not be won with a lightning campaign as in 1870 . Therefore , the Navy department decided to replace the six armored and seven light cruisers that had been sunk by that point in the war . Kaiser Wilhelm II requested the new ships be armed with 38 cm ( 15 inch ) guns ; Admiral Friedrich von Ingenohl , the commander in chief of the High Seas Fleet , preferred the 30 . 5 cm gun of the preceding " Derfflinger " - class ships . As a compromise , the new battlecruisers were to be armed with eight 35 cm ( 13 . 8 inch ) guns . The design staff was generally in agreement with the standard practice of using coal - fired boilers for two - thirds of the power plant , with the remainder being oil - fired boilers . Coal - fired boilers were preferred because the coal , stored in the sides of the ship , provided additional protection , particularly for the battlecruisers . There was a problem with any enlargement of the new ships over the preceding designs . The Imperial dry docks were only deep enough for ships with a draft of . This meant that an increase in displacement would necessitate a longer and wider hull . This was compounded by restrictions on width imposed by the locks of the canal in Wilhelmshaven . General characteristics . The " Mackensen " - class ships were long , had a beam of , and a draft of forward and aft . The ships were designed to displace on a standard load , and up to fully laden . The " Mackensen " s hulls were composed of longitudinal steel frames , over which the outer hull plates were riveted . This was the same type of construction as in the preceding " Derfflinger " - class battlecruisers , and was intended to save weight compared to the traditional method of construction , which incorporated both longitudinal and transverse frames . The ships ' hulls contained 18 watertight compartments and a double bottom that ran for 92 % of the length of the hull . This was significantly greater than the older " Derfflinger " - class ships , which had a double bottom for only 65 % of the length of the hull . The ships as designed required a crew of 46 officers and 1 , 140 enlisted sailors . Service as a squadron flagship would increase that number by an additional 14 officers and 62 sailors . The vessels carried a number of small boats , including two picket boats , one barge , two launches , two cutters , and three yawls . Machinery . The ships of the " Mackensen " class were equipped with four sets of marine - type turbine engines , each of which drove a three - bladed screw that was 4 . 2 m in diameter . The turbines mounted in " Fürst Bismarck " were equipped with Föltinger fluid transmission , while those on the other three ships were two sets of direct coupled turbines with geared transmissions . The ships had 24 coal - fired marine - type single ended boilers and eight oil - fired marine - type boilers . The power plants were designed to provide 90 , 000 shaft horsepower and 295 revolutions per minute . Maximum speed was rated at . The vessels were designed to store of coal and of oil in purpose - built storage spaces , though the hull areas between the torpedo bulkhead and the outer wall of the ship were used to store additional fuel . Maximum fuel capacity was of coal and of oil . This was estimated to give a range of up to about at a cruising speed of . Electrical power on the vessels was provided by eight diesel generators that put out 2 , 320 kilowatts at 220 volts . The ships were equipped with a pair of rudders mounted side by side , as opposed to the tandem rudders used on the " Derfflinger " - class ships . Armament . The " Mackensen " s were equipped with a main battery of eight new 35 cm ( 13 . 8 inch ) SK L / 45 guns in four twin gun turret s . The turrets were mounted in superfiring pairs fore and aft of the main superstructure . The guns were placed in Drh LC / 1914 mountings , which could elevate to 16 degrees and depress to −8 degrees . The guns were supplied with a total of 720 armor - piercing shells , or 90 per gun . The weapons were designed to fire 600 kg ( 1 , 323 lb ) shells at a rate of fire of around 2 . 5 shots per minute . The shells were fired with a muzzle velocity of 815 meters per second ( 2 , 674 f / s ) . As with other heavy German guns , these weapons used a fore propellant charge in a silk bag with a main charge in a brass case . These guns could hit targets out to a maximum distance of 20 , 000 m ( 21 , 870 yards ) . The ships ' secondary battery consisted of fourteen 15 cm ( 5 . 9 in ) SK L / 45 quick - firing guns mounted in armored casemate s along the central superstructure . Each gun was supplied with 160 rounds , and had a maximum range of 13 , 500 m , though this was later extended to 16 , 800 m . The guns had a sustained rate of fire of 5 to 7 rounds per minute . The shells were 45 . 3 kg ( 99 . 8 lb ) , and were loaded with a 13 . 7 kg ( 31 . 2 lb ) RPC / 12 propellant charge in a brass cartridge . The guns fired at a muzzle velocity of 835 meters per second ( 2 , 740 ft / s ) . The guns were expected to fire around 1 , 400 shells before they needed to be replaced . The ships were also armed with eight 8 . 8 cm ( 3 . 45 in ) L / 45 Flak guns in single pedestal mounts . Four were arranged around the rear superfiring main battery turret and the other four around the forward conning tower . The Flak guns were emplaced in MPL C / 13 mountings , which allowed depression to −10 degrees and elevation to 70 degrees . These guns fired 9 kg ( 19 . 8 lb ) shells , and had an effective ceiling of 9 , 150 m at 70 degrees . As was standard for warships of the period , the " Mackensen " s were equipped with submerged torpedo tubes . There were five tubes : one in the bow , and two on each flank of the ship . The torpedoes were the H8 type , which were long and carried a 210 kg ( 463 lb ) Hexanite warhead . The torpedoes had a range of 6 , 000 m ( 6 , 550 yd ) when set at a speed of 36 knots ; at a reduced speed of 30 knots , the range increased significantly to 14 , 000 m ( 15 , 310 yd ) . Armor . The " Mackensen " - class ships were protected with Krupp cemented steel armor , as was the standard for German warships of the period . The armor layout was very similar to the armor scheme on the preceding " Derfflinger " - class ships . They had an armor belt that was thick in the central citadel of the ship , where the most important parts of the ship were located . This included the ammunition magazines and the machinery spaces . The belt was reduced in less critical areas , to forward and aft . The belt tapered down to at the bow , though the stern was not protected by armor at all . A thick torpedo bulkhead ran the length of the hull , several meters behind the main belt . The main armored deck ranged in thickness from 30 mm thick in less important areas , to in the sections that covered the more critical areas of the ship . The forward conning tower was protected with heavy armor : the sides were 300 mm thick and the roof was thick . The rear conning tower was less well armored ; its sides were only thick and the roof was covered with of armor plate . The main battery gun turrets were also heavily armored : the turret sides were thick and the roofs were thick . The 15 cm guns had worth of armor plating in the casemates ; the guns themselves had thick shields to protect their crews from shell splinters . Construction and cancellation . Four ships were planned in the class : " Mackensen " , " Graf Spee " , " Prinz Eitel Friedrich " , and " Fürst Bismarck " . " Mackensen " — ordered under the provisional name " Ersatz Victoria Louise " — was named after Field Marshal August von Mackensen . The ship was laid down 30 January 1915 at Blohm & Voss in Hamburg , under construction number 240 . She was launched on 21 April 1917 , but construction was halted about 15 months before she would have been completed . " Mackensen " was stricken from the German navy , according to the terms of the Treaty of Versailles , on 17 November 1919 . She was sold for scrap and eventually broken up in 1922 at Kiel - Nordmole . " Graf Spee " was named for Vice Admiral Maximilian von Spee , the commander of the German East Asia Squadron ; he was killed when his squadron was annihilated at the Battle of the Falkland Islands in 1914 . " Graf Spee " was laid down 30 November 1915 in the Schichau yards in Danzig ( now Gdańsk , Poland ) , under the provisional name " Ersatz Blücher " . She was launched on 15 September 1917 . Construction stopped about 12 months away from completion ; " Graf Spee " was the furthest along of all four ships when work was halted . She too was struck on 17 November 1919 ; on 28 October 1921 the unfinished hull was sold for 4 . 4 million Marks and broken up in Kiel - Nordmole . " Prinz Eitel Friedrich " , ordered as " Ersatz Freya " — a replacement for , was named for one of Kaiser Wilhelm II ' s sons , Eitel Friedrich . She was laid down on 1 May 1915 at Blohm & Voss under construction number 241 . She was 21 months away from completion when she was launched to clear the slip on 13 March 1920 and was broken up at Hamburg in 1921 . At the launching ceremony , dockyard workers named the ship " Noske " , after " Reichswehr " Minister Gustav Noske . " Fürst Bismarck " , ordered as " Ersatz A " , was named for the famous German chancellor Otto von Bismarck . The ship was laid down on 3 November 1915 at the Kaiserliche Werft Wilhelmshaven under construction number 25 . She was about 26 months from completion when work ended . She was never launched ; instead , the vessel was broken up on the slip in 1922 . The primary reason construction halted on the four ships was the shifting of ship building priorities from capital ships to U - boat s . In the last two years of the war , what little resources were available to the navy were directed towards U - boat construction ; this caused a shortage of construction materials and slower build times for large warships . The RMA filed a report dated 1 February 1918 , which stated that capital ship construction had ground to a halt , primarily due to the shifting priorities to the U - boat war . Notes . Footnotes Citations References . Online sources