Ersatz Yorck - class battlecruiser The " Ersatz Yorck " class was a group of three battlecruisers ordered for the Imperial German Navy in April 1915 . The name derived from the fact that the lead ship was intended as a replacement ( German : " ersatz " ) for the armored cruiser lost to mines in 1914 . They were a slightly enlarged version of the , armed with guns as opposed to the weapons on the preceding design . The boilers would have been trunked into a single massive funnel . The three ships were originally ordered as part of the " Mackensen " class but the design was changed when details of the British s became known to German intelligence . The vessels were ordered under the provisional names " Ersatz Yorck " , " Ersatz Gneisenau " , and " Ersatz Scharnhorst " . They were considered to be replacements for the armored cruisers , which had been sunk by German mines in 1914 , and and , both of which had been sunk at the Battle of the Falkland Islands also in 1914 . As with the " Mackensen " s , the three ships of the " Ersatz Yorck " class were never completed . This was primarily due to shifting wartime construction priorities ; U - boat s were deemed more important to Germany ' s war effort , and so work on other types of ships was slowed or halted outright . The lead ship , " Ersatz Yorck " , was the only vessel of the three to have construction begin , though she was over two years from completion by the time work was abandoned . With the hull incomplete , the ship could not be launched and towed to ship - breakers ; as a result , " Ersatz Yorck " was broken up in situ . Design . General characteristics . The " Ersatz Yorck " - class ships were an enlargement of the previous " Mackensen " - class ships . They were long , compared to on the earlier vessels . " Ersatz Yorck " had the same beam as the earlier vessels , at , and the same draft of . The ships were planned to displace at standard weight , and up to fully laden . This was approximately heavier than the " Mackensen " s . The " Ersatz Yorck " - class ships ' hulls were to have been constructed with longitudinal steel frames with the outer plating riveted on . Machinery . As with all German battlecruisers that had been built , the " Ersatz Yorck " - class ships would have been equipped with four sets of Parsons turbine engines , each of which drove a 3 - bladed screw that was in diameter . The turbines were supplied with steam by 24 coal - fired Schulz - Thornycroft single ended boilers and 8 oil - fired Schulz - Thornycroft double ended boilers . " Ersatz Yorck " and " Ersatz Gneisenau " were intended to use Föttinger fluid transmission for their turbines , while " Ersatz Scharnhorst " s turbines retained direct coupled geared transmissions . The ships were to have electrical power provided by diesel generators . The " Ersatz Yorck " s were intended to mount a pair of twin rudders alongside each other for steering . The power plant was rated 90 , 000 shaft horsepower and 295 revolutions per minute , the same as the preceding " Mackensen " - class ships . Their slightly greater size reduced their speed somewhat , from in the " Mackensen " - class ships to for the new vessels . The ships were designed to store of coal and of oil in purpose - designed fuel bunkers . However , the areas of the hull between the torpedo bulkhead and the outer wall of the ship were also used for fuel storage . This additional space provided an increased total of of coal and of oil . With fuel stores topped off , the ships were estimated to have been able to steam for at a cruising speed of . Armament . The ships ' main battery was to have consisted of eight SK L / 45 guns in four Drh LC / 1913 twin gun turret s , placed in superfiring pairs fore and aft of the superstructure . These were the same " Langer Max " guns as those mounted on the s . The guns could initially depress to −8 degrees and elevate to 16 degrees ; this provided maximum range of 20 , 400 m . The gun mountings were modified to allow elevation up to 20 degrees ; the range was correspondingly increased to 23 , 200 m . The turrets could train 150 degrees to either side of the centerline . The main battery was supplied with a total of 720 shells or 90 rounds per gun . The guns had a rate of fire of around 2 . 5 shells per minute . Post - war tests conducted by the British Royal Navy showed that the guns on the battleship could be ready to fire again 23 seconds after firing ; this was significantly faster than their British contemporaries , the 38 cm guns on the , which took 36 seconds between salvos . The guns fired armor - piercing shells with a RPC / 12 propellant charge in a brass cartridge . The shells were fired at a muzzle velocity of 800 meters per second ( 2 , 625 fps ) . Each gun was expected to fire 300 shells before replacement was required . The ships ' secondary battery consisted of twelve 15 cm 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 , and were loaded with a 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 shells , and had an effective ceiling of 9 , 150 m at 70 degrees . As was standard for warships of the period , the " Ersatz Yorck " s were equipped with submerged torpedo tubes . There were three tubes : one in the bow , and one on each flank of the ship . The torpedoes were the H8 type , which were 8 m long and carried a Hexanite warhead . The torpedoes had a range of when set at a speed of 36 knots ; at a reduced speed of 30 knots , the range increased significantly to . Armor . The " Ersatz Yorck " - class ships were protected with Krupp cemented steel armor , as was the standard for German warships of the period . The armor layout was identical to the preceding " Mackensen " class , which was itself 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 . Three ships were ordered for the new design . " Ersatz Yorck " , a replacement for the armored cruiser , was ordered from AG Vulcan in Hamburg , laid down in July 1916 under construction number 63 . After 1917 , work on the ship only took place in order to keep dockyard workers occupied . Construction was suspended to concentrate on the U - boat program , and the hull frames that had been assembled were subsequently scrapped on the slip . " Ersatz Gneisenau " , a replacement for the armored cruiser , was ordered from Germaniawerft in Kiel under construction number 250 . Work was not started due to shifting priorities , though some material had been constructed . The diesel engines that had been built were subsequently installed on the first four Type U 151 U - boat s , , , and . " Ersatz Scharnhorst " , a replacement for the armored cruiser , was ordered from Blohm + Voss in Hamburg under construction number 246 . Construction never began on her as well , due to shifting priorities . However , the design formed the basis for the s built by the Kriegsmarine in the mid - 1930s . Notes . Footnotes Citations References . Online sources