Ersatz Yorck class battlecruiser
Encyclopedia
The Ersatz Yorck class were a group of three battlecruisers ordered for the Imperial German Navy
Kaiserliche Marine
The Imperial German Navy was the German Navy created at the time of the formation of the German Empire. It existed between 1871 and 1919, growing out of the small Prussian Navy and Norddeutsche Bundesmarine, which primarily had the mission of coastal defense. Kaiser Wilhelm II greatly expanded...

 in April 1915. The name derived from the fact that the lead ship was intended as a replacement (German:
ersatz
Ersatz
Ersatz means 'substituting for, and typically inferior in quality to', e.g. 'chicory is ersatz coffee'. It is a German word literally meaning substitute or replacement...

) for the armored cruiser
Armored cruiser
The armored cruiser was a type of warship of the late 19th and early 20th centuries. Like other types of cruiser, the armored cruiser was a long-range, independent warship, capable of defeating any ship apart from a battleship, and fast enough to outrun any battleships it encountered.The first...

  lost to mines in 1914. They were a slightly enlarged version of the , armed with 38 cm (15 in) guns as opposed to the 35 cm (13.8 in) 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 Admiral class battlecruisers
Admiral class battlecruiser
The Admiral-class battlecruisers were a class of four British Royal Navy battlecruisers designed near the end of World War I. Their design began as a improved version of the s, but it was recast as a battlecruiser after Admiral John Jellicoe, commander of the Grand Fleet, pointed out that there was...

 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 SMS Yorck, which had been sunk by German mines in 1914, and and , both of which had been sunk at the Battle of the Falkland Islands
Battle of the Falkland Islands
The Battle of the Falkland Islands was a British naval victory over the Imperial German Navy on 8 December 1914 during the First World War in the South Atlantic...

 also in 1914.

As with the
Mackensens, the three ships of the Ersatz Yorck class were never completed. This was primarily due to shifting wartime construction priorities; U-boat
U-boat
U-boat is the anglicized version of the German word U-Boot , itself an abbreviation of Unterseeboot , and refers to military submarines operated by Germany, particularly in World War I and World War II...

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.

General characteristics

The
Ersatz Yorck class ships were an enlargement of the previous Mackensen class ships. They were 227.8 m (747.4 ft) long, compared to 223 m (731.6 ft) on the earlier vessels. Ersatz Yorck had the same beam as the earlier vessels, at 30.4 m (99.7 ft), and the same draft of 9.3 m (30.5 ft). The ships were planned to displace 33500 metric tons (32,970.8 LT) at standard weight, and up to 38000 MT (37,399.7 LT) fully laden. This was approximately 2500 MT (2,460.5 LT) heavier than the Mackensens. The Ersatz Yorck class ships' hulls were to have been constructed with longitudinal steel frames with the outer plating rivet
Rivet
A rivet is a permanent mechanical fastener. Before being installed a rivet consists of a smooth cylindrical shaft with a head on one end. The end opposite the head is called the buck-tail. On installation the rivet is placed in a punched or pre-drilled hole, and the tail is upset, or bucked A rivet...

ed 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
Steam turbine
A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. Its modern manifestation was invented by Sir Charles Parsons in 1884....

, each of which drove a 3-bladed screw
Propeller
A propeller is a type of fan that transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the airfoil-shaped blade, and a fluid is accelerated behind the blade. Propeller dynamics can be modeled by both Bernoulli's...

 that was 4.2 m (13.8 ft) 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
Hermann Föttinger
Hermann Föttinger was a German engineer and inventor. In the course of his life he submitted over 100 patent applications, but he is most notable for inventing fluid coupling....

 Fluid transmission
Fluid coupling
A fluid coupling is a hydrodynamic device used to transmit rotating mechanical power. It has been used in automobile transmissions as an alternative to a mechanical clutch...

 for their turbines, while
Ersatz Scharnhorsts turbines retained direct coupled geared transmissions. The ships were to have electrical power provided by diesel generators. The Ersatz Yorcks were intended to mount a pair of twin rudder
Rudder
A rudder is a device used to steer a ship, boat, submarine, hovercraft, aircraft or other conveyance that moves through a medium . On an aircraft the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane...

s alongside each other for steering.

The power plant was rated 90,000 shaft horsepower and 295 revolutions per minute
Revolutions per minute
Revolutions per minute is a measure of the frequency of a rotation. It annotates the number of full rotations completed in one minute around a fixed axis...

, the same as the preceding
Mackensen class ships. Their slightly greater size reduced their speed somewhat, from 28 knots (15.2 m/s) in the Mackensen class ships to 27.3 knots (14.9 m/s) for the new vessels. The ships were designed to store 850 MT (836.6 LT) of coal and 250 MT (246.1 LT) of oil in purpose-designed fuel bunkers. However, the areas of the hull between the torpedo bulkhead
Torpedo bulkhead
A torpedo bulkhead is a type of armor common on the more heavily armored warships, especially battleships and battlecruisers of the early 20th century. It is designed to keep the ship afloat even if the hull was struck underneath the belt armor by a shell or by a torpedo...

 and the outer wall of the ship were also used for fuel storage. This additional space provided an increased total of 4000 MT (3,936.8 LT) of coal and 2000 MT (1,968.4 LT) of oil. With fuel stores topped off, the ships were estimated to have been able to steam for 5500 nautical miles (10,186 km) at a cruising speed of 14 kn (7.6 m/s).

Armament

The ships' main battery was to have consisted of eight 38 cm (15 in) SK L/45 gunsIn Imperial German Navy gun nomenclature, "SK" (Schnellfeuerkanone) denotes that the gun quick firing, while the L/45 denotes the length of the gun. In this case, the L/45 gun is 45 calibers, meaning that the gun barrel is 45 times as long as it is in diameter. in four Drh LC/1913 twin gun turret
Gun turret
A gun turret is a weapon mount that protects the crew or mechanism of a projectile-firing weapon and at the same time lets the weapon be aimed and fired in many directions.The turret is also a rotating weapon platform...

s, placed in superfiring pairs
Superfire
The idea of superfire is to locate two turrets in a row, one behind the other, but with the second turret located above the one in front so that the second turret could fire over the first...

 fore and aft of the superstructure
Superstructure
A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships...

. 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
Rate of fire
Rate of fire is the frequency at which a specific weapon can fire or launch its projectiles. It is usually measured in rounds per minute , or per second .-Overview:...

 of around 2.5 shells per minute. Post-war tests conducted by the British Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 showed that the guns on the battleship Baden 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 750 kg (1,653.5 lb) armor-piercing shells with a 277 kg (610.7 lb) RPC/12 propellant
Propellant
A propellant is a material that produces pressurized gas that:* can be directed through a nozzle, thereby producing thrust ;...

 charge in a brass cartridge. The shells were fired at a muzzle velocity
Muzzle velocity
Muzzle velocity is the speed a projectile has at the moment it leaves the muzzle of the gun. Muzzle velocities range from approximately to in black powder muskets , to more than in modern rifles with high-performance cartridges such as the .220 Swift and .204 Ruger, all the way to for tank guns...

 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
Casemate
A casemate, sometimes rendered casement, is a fortified gun emplacement or armored structure from which guns are fired. originally a vaulted chamber in a fortress.-Origin of the term:...

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
Rate of fire
Rate of fire is the frequency at which a specific weapon can fire or launch its projectiles. It is usually measured in rounds per minute , or per second .-Overview:...

 of 5 to 7 rounds per minute. The shells were 45.3 kg (100 lb), and were loaded with a 13.7 kg (30 lb) RPC/12 propellant
Propellant
A propellant is a material that produces pressurized gas that:* can be directed through a nozzle, thereby producing thrust ;...

 charge in a brass cartridge. The guns fired at a muzzle velocity
Muzzle velocity
Muzzle velocity is the speed a projectile has at the moment it leaves the muzzle of the gun. Muzzle velocities range from approximately to in black powder muskets , to more than in modern rifles with high-performance cartridges such as the .220 Swift and .204 Ruger, all the way to for tank guns...

 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
Conning tower
A conning tower is a raised platform on a ship or submarine, often armored, from which an officer can con the vessel; i.e., give directions to the helmsman. It is usually located as high on the ship as practical, to give the conning team good visibility....

. 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 (20 lb) shells, and had an effective ceiling of 9,150 m at 70 degrees.

As was standard for warships of the period, the Ersatz Yorcks were equipped with submerged torpedo tubes. There were three 60 cm (23.6 in) 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 210 kg (463 lb) Hexanite warhead. The torpedoes had a range of 6000 m (6,561.7 yd) when set at a speed of 36 knots; at a reduced speed of 30 knots, the range increased significantly to 14000 m (15,310.6 yd).

Armor

The Ersatz Yorck class ships were protected with Krupp
Krupp
The Krupp family , a prominent 400-year-old German dynasty from Essen, have become famous for their steel production and for their manufacture of ammunition and armaments. The family business, known as Friedrich Krupp AG Hoesch-Krupp, was the largest company in Europe at the beginning of the 20th...

 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.The figures listed here are those for the Derfflinger class; specific figures for the Ersatz Yorck class are unknown. German naval historian Erich Gröner states "The outfit of Krupp armour was similar to that of the Derfflinger class. See: Gröner, p. 57 They had an armor belt that was 300 mm (11.8 in) 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 120 mm (4.7 in) forward and 100 mm (3.9 in) aft. The belt tapered down to 30 mm (1.2 in) at the bow
Bow (ship)
The bow is a nautical term that refers to the forward part of the hull of a ship or boat, the point that is most forward when the vessel is underway. Both of the adjectives fore and forward mean towards the bow...

, though the stern
Stern
The stern is the rear or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern lies opposite of the bow, the foremost part of a ship. Originally, the term only referred to the aft port section...

 was not protected by armor at all. A 45 mm (1.8 in) thick torpedo bulkhead
Torpedo bulkhead
A torpedo bulkhead is a type of armor common on the more heavily armored warships, especially battleships and battlecruisers of the early 20th century. It is designed to keep the ship afloat even if the hull was struck underneath the belt armor by a shell or by a torpedo...

 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 80 mm (3.1 in) in the sections that covered the more critical areas of the ship.

The forward conning tower
Conning tower
A conning tower is a raised platform on a ship or submarine, often armored, from which an officer can con the vessel; i.e., give directions to the helmsman. It is usually located as high on the ship as practical, to give the conning team good visibility....

 was protected with heavy armor: the sides were 300 mm thick and the roof was 130 mm (5.1 in) thick. The rear conning tower was less well armored; its sides were only 200 mm (7.9 in) thick and the roof was covered with 50 mm (2 in) of armor plate. The main battery gun turrets were also heavily armored: the turret sides were 270 mm (10.6 in) thick and the roofs were 110 mm (4.3 in) thick. The 15 cm guns had 150 mm (5.9 in) worth of armor plating in the casemates; the guns themselves had 70 mm (2.8 in) 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
Armored cruiser
The armored cruiser was a type of warship of the late 19th and early 20th centuries. Like other types of cruiser, the armored cruiser was a long-range, independent warship, capable of defeating any ship apart from a battleship, and fast enough to outrun any battleships it encountered.The first...

 , was ordered from AG Vulcan in Hamburg
Hamburg
-History:The first historic name for the city was, according to Claudius Ptolemy's reports, Treva.But the city takes its modern name, Hamburg, from the first permanent building on the site, a castle whose construction was ordered by the Emperor Charlemagne in AD 808...

, 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
U-boat
U-boat is the anglicized version of the German word U-Boot , itself an abbreviation of Unterseeboot , and refers to military submarines operated by Germany, particularly in World War I and World War II...

 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
Friedrich Krupp Germaniawerft
Friedrich Krupp Germaniawerft was a German shipbuilding company, located in the harbour at Kiel, and one of the largest and most important builders of U-boats for the Kaiserliche Marine in World War I and the Kriegsmarine in World War II.-History:The company was founded in 1867 by Lloyd Foster, as...

 in Kiel
Kiel
Kiel is the capital and most populous city in the northern German state of Schleswig-Holstein, with a population of 238,049 .Kiel is approximately north of Hamburg. Due to its geographic location in the north of Germany, the southeast of the Jutland peninsula, and the southwestern shore of the...

 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
German Type U 151 submarine
Type U 151 U-boats were a class of large, long-range submarines constructed during World War I by the Kaiserliche Marine.-Background:In addition to the cargo-carrying submarine Deutschland, six further large cargo submarines were ordered, originally designed to ship material to and from locations...

 U-boat
U-boat
U-boat is the anglicized version of the German word U-Boot , itself an abbreviation of Unterseeboot , and refers to military submarines operated by Germany, particularly in World War I and World War II...

s U-151, U-152
SM U-152
SM U-152 was a German Type U 151 submarine of the Kaiserliche Marine during World War I.Built at Hamburg, the submarine was commissioned in October 1917...

, U-153
SM U-153
SM U-153 was one of the 329 submarines serving in the Imperial German Navy in World War I.U-153 was engaged in the naval warfare and took part in the First Battle of the Atlantic....

, and U-154
SM U-154
SM U-154 was one of the 329 submarines serving in the Imperial German Navy in World War I.U-154 was engaged in the naval warfare and took part in the First Battle of the Atlantic....

. Ersatz Scharnhorst, a replacement for the armored cruiser , was ordered from Blohm + Voss
Blohm + Voss
Blohm + Voss , is a German shipbuilding and engineering works. It is a subsidiary of ThyssenKrupp Marine Systems; there were plans to sell 80% of Blohm + Voss to Abu Dhabi Mar Group, but talks collapsed in July 2011.-History:It was founded on April 5, 1877, by Hermann Blohm and Ernst Voss as a...

 in Hamburg
Hamburg
-History:The first historic name for the city was, according to Claudius Ptolemy's reports, Treva.But the city takes its modern name, Hamburg, from the first permanent building on the site, a castle whose construction was ordered by the Emperor Charlemagne in AD 808...

 under construction number 246. Construction never began on her as well, due to shifting priorities. However, the design formed the basis for the Scharnhorst class battleships built by the Kriegsmarine
Kriegsmarine
The Kriegsmarine was the name of the German Navy during the Nazi regime . It superseded the Kaiserliche Marine of World War I and the post-war Reichsmarine. The Kriegsmarine was one of three official branches of the Wehrmacht, the unified armed forces of Nazi Germany.The Kriegsmarine grew rapidly...

in the mid 1930s.
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