Yamato class

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Yamato class
Japanese battleship Yamato running trials in Sukumo Bay, 30 October 1941 (80-G-704702) .jpg
Overview
Type: Battleship
Units: 5 planned, of which 2 deleted
Predecessor class: Tosa class
Successor class: no
Technical specifications
Displacement: Standard: 65,000 tn. l.
Length: over everything: 263 m
Width: 38.9 m
Draft: Trial: 10.40 m
Speed: 27 kn
Range: 7200  nautical miles at 16 knots
Drive: 4 screws over 4 shafts

The Yamato class ( Japanese 大 和 型 戦 艦 ; Yamato-gata Senkan ) was a class of five battleships of the Japanese Navy , of which only the first two, the Yamato and the Musashi , actually put into service as battleships and used in the Pacific War were. These remained to this day the largest, most heavily armed, and most heavily armored battleships ever built. The third ship, the Shinano , was completed as an aircraft carrier . The construction of two more ships was canceled and the hulls scrapped.

Neither battleship of the class ever got into the situation they were designed for - an artillery duel with an enemy battleship - but both fell victim to attacks by dozens of aircraft. The Shinano was lost in a submarine attack.

history

planning

Naval Minister Nagano , one of the proponents of the battleship doctrine and the construction of the Yamato class

When Japan left the League of Nations after the Mukden incident in March 1933, the Japanese General Staff asked the navy developers to design a new battleship. With the exit from the League of Nations and the subsequent termination of the naval contracts, no longer bound by the restrictions on warship construction, the requirements for the new class of ships exceeded the dimensions of all previously planned battleships. A main artillery with guns of at least 46 cm and armor protection, which should withstand 46-cm shells fired from a distance of between 20 and 35 kilometers, as well as a speed of over 30 knots were required.

The idea behind these requirements was to create a class of ships that compensated for the numerical superiority of the American United States Navy , which the Japanese planners had identified as the most likely enemy in the future, with a few battleships with particularly high combat strength. Since the United States bordered both the Atlantic and the Pacific , their ships had to use the Panama Canal to get from one ocean to another quickly . Consequently, American battleships could never exceed a certain width as they had to fit through the narrow locks of the canal. Since the increase in armor protection and the increase in the caliber of the main artillery inevitably increased the ship's width, so the theory goes, no American battleship planned under the conditions mentioned could ever achieve the combat strength of the new Japanese battleship class.

The construction was controversial, and early advocates of a tactic that favored aircraft carriers over battleships, such as the later commander in chief of the Imperial Japanese Navy, Yamamoto , opposed the project, but were not heard by their superiors.

implementation

The order for development came from the General Staff of the Navy, under the leadership of its Chief of Staff, Fleet Admiral Prince Fushimi Hiroyasu . Rear Admiral Keiji Fukuda was responsible for the planning. The basics of the construction are attributed to Yuzuru Hiraga, who had already outlined the plans for a comparable ship under the designation A140-A years earlier. After two years with different designs, 46 cm L / 45 guns and particularly reliable machines had been decided upon. Although the maximum speed was reduced well below the initially required 30 knots, the machinery was located under 20 cm thick armor plates, so that a low-maintenance machine configuration was chosen. The functionality of some of the ideas for the bridge structure that had been planned for the Yamato class was first tested in 1936 when the battleship Hiei was modernized .

Eventually, three large models of Yamato ships were made four, six and eight meters long to test various aspects of the hull shape.

Since the ship's width had assumed an unfavorable ratio to the ship's length of 1: 6 in the course of the planning, the hull speed was correspondingly low. By adding a bulbous bow, the developers reduced the resistance value of the hull by 5 to 6% at full speed. In order to reduce the overall weight, the upper deck was first led in a straight line over the engine rooms coming from the stern and then moved towards the bow in a slightly convex line so that the upper deck reached its lowest point at about the level of the front main gun turret it rose again towards the bow. This deck jump is sometimes referred to as the "Kampon Line".

In order to reduce the turning circle of the ships, a stern shape was chosen that was not excessively elongated aft, as was customary with other types of ships to increase the length, so that the maneuverability was improved. The ships had two rudders : a main and an auxiliary rudder. The auxiliary rudder was installed in front of the main rudder and was significantly smaller. It was not able to compensate for the effects of the main rudder when the rudder was shifted hard by counter-steering, but should ensure a certain degree of steering control in the event of a total loss of the main rudder.

In order to reduce the weight of riveting steel plates, the construction of the Yamato class also made use of arc welding , which is still relatively seldom used in Japan .

Financing and confidentiality

An important element of the Navy's planning was the absolute secrecy of the true dimensions of their battleships. Since it was not possible to hide the construction of the ships themselves, it was decided to hide the information about the technical data. For example, an application was made to the Japanese government for funds for the construction of two 35,000-ton battleships, knowing full well that these funds would not be sufficient for the construction of the first two battleships of the Yamato class . On January 19, 1937, Secretary of the Navy Nagano received approval to finance a construction program that included 66 warships, including funds to build the two Yamato-class ships .

While a ship was to be laid down in a naval shipyard in Kure, the second ship was to be built by a private shipyard in Nagasaki . In order to disguise the real costs here too, a contract was signed with the shipyard which only showed a relatively small amount. However, the navy took over the manufacture and delivery of armor plates for this ship from their workshops in Kure for free, so that the amount to be paid to the shipyard did not allow any conclusions to be drawn about the dimensions of the Musashi . The measures taken by the Navy to raise the additional funds required were varied. For example, after only eight ships of the Ōtori class had been built, the program was canceled after funds for 16 ships of the class had been made available by the state in order to use the money saved to build Yamato and Musashi .

The construction of the ships themselves was accompanied by the erection of privacy screens, various degrees of access restrictions and extensive measures by the police and secret service. The efforts were having an effect, and by the end of the war the Americans assumed that the water displacement and the main armament were too small.

technical description

Machine systems

Battleship Yamato
Battleship Musashi

Propulsion system

After it was not possible to develop a powerful, reliable marine diesel engine in the allotted time, a decision was made in favor of a system consisting of conventional steam boilers with downstream turbines . The boilers burned heavy oil through their burners to evaporate water. The pressurized steam was used via steam pipes to operate the turbines, which ultimately moved the four shafts with the propellers . Each propeller had a diameter of five meters and was made from a mixture of bronze and manganese .

The ship class received twelve Kampon steam boilers, which were installed in four rows of three. Each boiler was in its own compartment, the three boilers in each row supplied 325  ° C steam with a pressure of 24.4  bar to the turbine behind. Two adjacent boilers on port and starboard shared a separate fuel supply, which could pump the fuel from up to four tanks in the double bottom of the ships.

The engine rooms with their turbines produced up to 150,000 SHP (167,000 SHP maximum output) in use. When all machines ran at full power, the twelve boilers with their nine burners each consumed 62.7 metric tons of fuel per hour, so that a speed of 27 knots could be maintained. Under test conditions, a top speed of 28.05 knots was temporarily reached on June 22, 1942 with a shaft speed of 230 revolutions per minute.

The fuel supply was around 6,300 tons of heavy fuel oil.

Electrical system

The eight 600 kW generators of the Yamato class supplied direct current with a voltage of 225 volts. Four generator rooms were in front, the other four aft of the engine rooms, each with a control station for four generators. All generators were connected to one another by a cable duct that ran under armor protection in the middle of the ship. Half of the generators were operated with diesel fuel , the other four were turbo generators, which were designed in such a way that they could supply all electrical consumers with energy alone during a battle in an emergency.

The ship's systems could also be operated by three batteries with 112 accumulator cells each , and an additional block was available for emergency operation of the steering gear.

Armament

The two front 16-inch treble towers on the Musashi . At the time of the exposure, the ship does not yet have radar antennas on the main rangefinder. The deck jump is clearly visible.

46 cm

The main armament of the battleships of the Yamato class consisted of nine 46 cm guns , which were housed in three triple turrets. All the towers stood along the longitudinal axis of the ships, two stood on the forecastle, with tower "B" being built too high.

Each tower with armor and three tubes weighed around 2,510 tons and could be swiveled to the sides at a speed of 2 ° per second by hydraulic pumps . The pipe elevation could be changed at a rate of 10 ° per second.

All three towers each had a stereoscopic range finder with a base length of 15 meters and a simple 10 cm observation telescope .

The guns had a comparatively short barrel length in relation to their long range, so that the dispersion of the impacts at maximum firing range was quite high. In order to increase the probability of a hit, the ships of the Yamato class each had nine of these guns on board distributed across three triple turrets. When firing four and five salvos , the two outer tubes of a triple tower could be fired at the same time, while the charge in the middle was ignited with a delay of 0.08 seconds. The range of these volleys was up to 550 meters. When all nine guns were fired in a single salvo, the spread was greater.

The guns had to be lowered to recharge to 3 ° so that at maximum firing range a cadence of 1.5 rounds per minute can not be exceeded. With shorter firing ranges, the reloading time was shortened, so that a shot could be fired every 30 seconds with a barrel elevation of 3 °.

Since the main guns generated a strong pressure wave when fired , parts of the superstructure and the arrangement of equipment on deck had to be arranged so that nothing could be damaged. Intake openings for fans and anti-aircraft armament were not installed in the effective area of ​​the pressure wave, but instead installed in the center of the ship or pulled together directly on the main gun turrets. All dinghies carried by the Yamato class had to be housed in garages at the stern. A rail on the underside of the flight deck was installed on the port and starboard sides to enable boats to be set down and picked up quickly, via which the boats could be pushed aft from their parking position in the garage to their set down position before they were lowered . Further boats were stored in front of the shaft to the aircraft hangar under the rear part of the flight deck and had to be launched with the aircraft crane. For picking up boats and goods, davits were also installed on the outside of the ship's side, which could be swiveled out if necessary.

15.5 cm

The secondary armament of the Yamato class , also known as medium artillery , initially consisted of four turrets with three 15.5 cm guns each. Two of these towers stood on the longitudinal axes of each ship, the other two were set up amidships, one on the port and one on the starboard side. However, as part of the renovation work carried out during the Pacific War, the port and starboard turrets were removed to make room for additional anti-aircraft cannons.

The 15.5 cm guns with the model designation year 3 were based on developments, some of which came from 1914. The 12.7 ton gun could accelerate a 56 kg shell to up to 980 meters per second, shoot up to 27 kilometers and was designed to combat ship targets. The guns came from the Mogami-class cruisers that were converted to 20.3 cm guns in 1939 .

Each tower weighed between 160 and 180 tons and could be swiveled at a speed of up to 6 ° per second. The pipe elevation could be changed at 10 ° per second. The maximum achievable rate of fire was five to six rounds per minute. Each tower had a range finder with a base length of eight meters.

Air defense

This photo, taken during a visit to the Shōwa-Tennō in July 1943, shows a 25 mm Type 96 triple automatic cannon in the foreground on the bridge tower of the Musashi and several 12.7 cm Type 89 anti-aircraft cannons in the background

When planning the ships, six 12.7 cm anti-aircraft guns type 89 , each consisting of a double mount A1 Mod. 3, were considered to be sufficiently heavy anti-aircraft armament for long and medium distances. On the port and starboard sides, three of these Type 89 cannons were placed at the level of the funnel, where they were installed in an elevated position so that they could fire over the 15.5 cm triple turret installed in front of them.

The cannons fired 23 kg grenades, which exploded after a preset time before firing, releasing fragments that should be sufficient to destroy any aerial target within a radius of 18.8 meters. The cannons could be pointed up to 75 ° and at this angle fire their grenades up to 9,400 meters.

After it was decided to strengthen the Yamato-class anti-aircraft equipment during the Pacific War, the two 15.5-cm towers amidships were removed and six more Type 89 anti-aircraft guns were planned in their place. However, this conversion was only completed on the Yamato before it was sunk .

For short-range defense against aircraft, the Japanese developers were based on the 25 mm L / 60 machine gun Type 96 . This cannon had been used on most Japanese warships from 1936 and was installed in the Yamato class as a triple gun in the variant produced in large numbers. The weapon could fire 250 gram bullets up to 7,500 meters, but its effective range was limited to 3,000 meters. Each of these triple cannons required nine soldiers to operate, six of which were assigned to quickly reload the box magazines, which only held 15 rounds, and two for each barrel. An effective rate of around 120 rounds per minute was achieved.

The number of 25 mm triplet mounts on the battleships of the Yamato class was initially only eight, but grew steadily as the war progressed, so that the Yamato carried 152 25 mm automatic cannons on its last use, most of which were built into triplet mounts were.

Changes to anti-aircraft armament on Yamato-class battleships
When they were completed, Yamato and Musashi each carried six Type 89 double mounts and 24 Type 96 automatic cannons in eight triplet turrets. In the middle of the ship there was a tower of the middle artillery on port and starboard each with three 15.5 cm guns, which could be used against ship targets, but were not suitable for combating air targets.
Musashi1942.png
The Musashi initially carried the standard armament for air defense with six Type 89 double and eight Type 96 triple mounts. The planned modifications of 1944 were not completed, the two towers with three 15.5 cm guns each were removed and the superstructures for six more Type 89 double mounts were installed, but the appropriate guns were before the ship's last use unavailable.

So the final armament in October 1944 was an interim solution with an increased number of a total of 111 Type 96 automatic cannons, some of which were placed on the new superstructures for the planned additional Type 89 mounts.

Musashi1944.png
The Yamato initially carried the standard armament for air defense with six Type 89 double mounts and 24 Type 96 automatic cannons. After the modifications in 1944, it carried twelve Type 89 double mounts and 113 Type 96 automatic cannons. Particularly noticeable was the replacement of the Type 89 A1 Model 3 mounts from the elevated position next to the chimneys to the lower-lying new extensions. The previous positions were equipped with the simple, open Type 89 A1 mounts.

The attempt to further improve the air defense capacity led to the addition of more Type 96 automatic cannons, so that their number reached 152 tubes in April 1945.

Yamato1945.png
The bridge tower of the battleship Musashi shortly after its completion. At the top of this tower there is an observation dome, at the base of which the arms of the 15-meter range finder are installed. Halfway up the roof of the main bridge there are two fire control devices for combating air targets in the upper angle groups, below this bridge a fire control device for air targets in low angle groups is installed. A little deeper you can see two viewing slits of the armored command post.

Shinano

As an aircraft carrier, it had neither main nor middle artillery. It carried eight 12.7 cm double mounts Type 89 on the sides of the flight deck and 155 automatic cannons of the type 96. In addition, twelve rocket launchers were installed, each of which could fire 28 unguided rockets with a caliber of 12 cm. The 23.9 kg rockets had a range of around 4,400 meters and had a high-explosive incendiary warhead that exploded after reaching a predetermined distance.

Others

After severe damage caused by a test explosion in the torpedo rooms of the battleship Tosa , no more torpedoes were planned for the Yamato class . The installation of 12 cm rocket launchers, such as those used on the Shinano , is also discussed for Musashi and Yamato in some publications , but there is no reliable evidence for this either.

Reconnaissance and fire control systems

Planes

Due to the enormous range of the main artillery of up to 42 kilometers , the impacts of the own shells could not be observed from board at great combat distances due to the limited field of view due to the curvature of the earth . The ships were therefore able to carry up to seven Aichi E13A and Mitsubishi F1M aircraft for fire control, which were transported on the stern and in a hangar below . The launch took place via two aircraft catapults at the rear. The artillery fire should then be directed by radio over the target. When they returned, the machines landed on the water and were lifted back onto the ship by a crane at the stern.

Range finders and radar systems

The battleships of the class had five large optical rangefinders for fire control of the main artillery for distances within sight . Three devices with a base length of 15 meters were installed in the towers and another as the main rangefinder on the roof of the bridge tower. A reserve device with a base length of ten meters stood on the roof of the aft structure. For the heavy 12.7 cm anti-aircraft guns, Type 94 rangefinders were used, which were not coupled to radar systems and were therefore only conditionally suitable for night combat. They could be used in daylight to capture both air and ship targets. The Yamato contributed to its demise in 1945 four Type 94 rangefinder for twelve 12.7-cm double carriages that Musashi in its sinking in 1944 two of her six double carriages.

The two battleships of the class were equipped with different radar systems. The first systems belonged to the Type 21 and were installed on the two arms of the main rangefinder from September 1942. The system was improved several times, so that in 1945 the Yamato already carried the third variant of the Type 21 radar.

A more powerful surface search radar was installed on both battleships from 1943 in addition to the Type 21 system. This Type 22 system for fire control of the artillery was installed on both ships to port and starboard of the bridge tower. The type of installation and the performance values ​​of the Type 22 on both ships differed slightly.

The Type 13 system was the last system to be retrofitted in 1944. It was mounted on the main mast in the form of two Yagi-Uda antennas and could be used to search for aerial and surface targets.

Shinano

The Shinano also carried two Type 21 and two Type 13 radar antennas, but no Type 22 system. She also used Type 94 range finders for the fire control of her heavy air defense.

Armor protection

Composition of the armor elements on the outside of the hull amidships

The designers chose an “all or nothing” armor protection for the Yamato class , in which they invested almost all of the weight available to them for armor into an extremely heavily armored citadel for the vital ship systems while it was running Inside this citadel and in the rest of the hull there was hardly any armor protection worth mentioning, only watertight compartments made of normal steel. Of a total of 1,147 watertight compartments in the ship's hull, only 82 were not under an armored deck, but some of these were large storage rooms, which turned out to be a serious disadvantage , especially when the Musashi sank.

The ships were designed to have sufficient buoyancy and not sink in the event of a flooding of all departments outside the armor protection. When flooding all departments outside the torpedo bulkhead on only one side, a side inclination of 18 ° should not be exceeded.

The developers chose the following types of armor steel to implement their armor concept :

NVNC - New Vickers Non Cemented, also called nitsukeru kurōmu kō (hardened chrome steel) by the Japanese , was the standard type of steel in Japanese battleship construction and was used for all armor in ships, with the exception of belt armor, the turrets of the main artillery, the armored deck and the embankment of the citadel used.

CNC - Copper Non Cemented, ( copper not cemented), a steel having a nickel alloy . CNC was sometimes used as a replacement for NVNC if the armor plates to be produced did not exceed a certain thickness (75 mm), as CNC was only considered to be superior to NVNC armor when it comes to thin plates. The amount of copper used was 0.9 to 1.3%, while it contained up to 3% nickel.

MNC - Molybdenum Alloy Non Cemented, ( molybdenum alloy not cemented) was used for the armored deck and the bank, as the Japanese engineers considered this type of steel more resistant to projectiles, the smashing of steep angles than was at NVNC steels the case . In particular, the splintering of the steel plates in the event of severe impacts should occur less frequently with MNC steel. Molybdenum alloy steel was first produced on a large scale by the Japanese factories only a few years before the start of the Pacific War and did not differ significantly in quality from comparable American armor plates.

VH - Vickers Hardened Non Cemented, was the only type of steel used in the Yamato class that was subsequently case hardened . It was used for the upper part of the belt armor of the ships, for armoring the main turrets and for the armored command post. The chemical composition corresponded to that of NVNC steel, however the VH armor plates were considered to be superior for particularly thick plates (over 33 cm). The Japanese engineers had already produced a 400 mm thick plate made of VH steel as a test run for future armor plates in 1936. However, they encountered problems during fire tests with heavy grenades and high impact speeds - the plate broke because upper bainite had formed in the steel during an uneven cooling process . Only after they had determined the optimal starting depth for the production of VH steel in numerous test runs were they able to produce steel plates of the required quality. Despite these efforts, the VH armor plates ultimately used are rated in the specialist literature as being around 10% worse in quality than the contemporary A-class armor plates of the US Navy.

Protection systems of the trunk

The armor protection of the hull was primarily designed to protect the important ship systems from steep and flat path fire from enemy battleships up to 46 cm grenades. The structural protection system of the hull was intended to weaken an underwater explosion of 400 kg of TNT explosives in such a way that the ship would not be damaged that could endanger its buoyancy.

The boiler and engine rooms as well as the grenade and powder chambers were surrounded by an armored citadel. This box inside the hull was closed at the top by the 200 mm thick armored deck, which merged with the 230 mm thick embankment at its outer edges. The embankment was connected to the 410 mm thick belt armor on the sides of the ship, which did not slope vertically, but was inclined inward by 20 ° so that it merged directly into the torpedo bulkhead at its lower edge . Due to this inclined design of the belt armor, the thickness of the armor, which had to be penetrated by a horizontally impacting projectile, increased to up to 584 mm.

The armor plate of the torpedo bulkhead was 203 mm thick at the connection to the belt armor and tapered to 75 mm on the way to the bottom of the ship. The double ship's bottom itself was reinforced on the outside with a 22 mm armor plate, over which tanks for fuel and water lay. Above these tanks there was another armor plate of 14 mm, which formed the floor plate of the engine rooms. All fuel supplies were stored under armor protection, mainly between the outer and inner soil. The torpedo bulges on the sides of the ship did not contain any fuel tanks.

The two decks above the citadel were protected with comparatively thin armor plates. The outside of the weather deck was protected by two layers of armor plates, which together were almost 40 mm thick; below the superstructure, the thickness was reduced to 12 mm. The intermediate deck below received a ceiling made of 10 mm armored steel, but was also 25 mm thicker to port and starboard than in the middle of the ship.

At the height of the turrets, the protection system in the hull differed from the rest of the ship. In order to ensure the best possible protection of the powder chambers with the cartridges , another armor plate was installed under the belt armor, which angled inwards towards the keel behind the torpedo bulkhead, so that these plates on both sides of the ship combined to form a tub in which the ammunition stores are stored were. The bulkhead was also made much thicker at 270 mm than in the rest of the ship and only decreased in thickness to 175 mm towards the bottom of the ship. The additional armor plates under the magazines and the reinforced base plate in the middle had a thickness of 80 mm and 50 mm CNC steel and thus formed a triple floor and significantly better protection than the rest of the hull.

The structural protection system against hits from torpedoes or sea ​​mines consisted of two watertight compartments within the torpedo bulge, followed by the torpedo bulkhead and two further compartments. The department that followed the torpedo bulkhead again had a reinforced longitudinal bulkhead made of CNC armored steel.

The connection of belt armor to the torpedo bulkhead underneath was already problematic in the planning phase, since, based on the results of the fire tests on the hull of the Tosa , the torpedo bulkhead in the upper part of the Yamato class should be thicker than originally intended to also protect against grenades that hit the water at a shallow angle and continued on their way there to be effective.

For the new connection between belt armor and torpedo bulkhead, which became so necessary, a solution made of riveted individual plates was chosen, which was criticized by several officers . In the given construction period, however, this was the only option that could be offered by the industry. The combination of belt armor and torpedo bulkhead proved to be inadequate for the explosions of American torpedoes, and most of the documented torpedo hits caused damage behind this bulkhead inside the armored citadel.

The only exception to the rest of the armor concept were the steering gear rooms, which were located outside the citadel, but were nevertheless heavily armored. For the main steering engine room, 350 mm armor is assumed on the sides, closed off by a 350 mm bulkhead towards the aft and a 360 mm bulkhead towards the front.

Towers

The three main turrets with the 46 cm guns were armored at the front with 65 cm thick VH steel plates. The sides of the tower had armor 25 cm thick. The tower ceiling had 27 cm armor, the rear had a 19 cm thick armor plate and a 40 cm plate, which, however, served less for protective purposes and was intended as a counterweight. The cylindrical structures of the barbeds on which the towers were seated also had VH armor up to 56 cm thick.

The turrets for the 15.5 cm guns had 7.5 cm armor on the front, and 2.5 cm armor was installed on the top and sides. The barbeds were armored 7.5 cm thick.

Command post

The Japanese Navy attached particular importance to an armored command post, from which the ship should still be guided, even in the event of severe destruction of the other bridge structures. This command post was in the lower half of the bridge structure, immediately behind the front 15.5 cm gun turret. It was windowless, provided with few viewing slits and had a 50 cm thick armor made of VH steel and a 20 cm thick VH armor on the top. An armored vertical shaft connected it to the control center, which was located inside the armored citadel in the ship's hull.

Shinano

The Shinano was redesigned from a battleship to an aircraft carrier during the construction phase. She retained the torpedo bulkhead and the structural protection system of the Yamato class , but her belt armor was only half as strong as that of her sister ships at around 200 mm. Only at the level of the ammunition chambers did he grow to 350 mm. The heavy horizontal armored deck of the battleships was retained at 200 mm, plus an armored flight deck, which, similar to that of the Taihō , was made of around 80 mm thick NVNC armored steel, supported on a regular 20 mm steel deck.

Displacement

The exact data of the water displacement of the Yamato class differ considerably, depending on the sources used. At the end of the war, two units of measurement could be used for the water displacement of battleships:

the British ton , also “long ton” (abbreviated as “tn. l.”), with 1016.047 kg per ton
the metric ton (abbreviated here as "tm" for better differentiation), with 1,000 kg per ton

The following table compares the data from various standard works with the data collected by the Americans in 1946 as part of the US Navy Technical Mission To Japan . As far as it could be seen which weight unit was used or which equipment level of the ships was described, this is noted. The indication "tons" indicates that an author has not given any details about this unit of weight and it is not clear which of the two units "tons" should stand for.

The differences between standard displacement, displacement under test conditions and displacement with a full charge result essentially from the different amounts of fuel and boiler water carried. The fuel quantities that the various authors have asked for or calculated for the Yamato class are listed in the last column.

Displacement data
Data on Yamato and Musashi by: when fully charged Test conditions Standard displacement Fuel supply ( heavy fuel oil )
USNTMJ S-01-4 (1946), for 1942 - 69,935 tm - 5,264.86 tm
USNTMJ S-01-3 (1946) 72,200 tm 69,935 tm 62–63,000 tm -
Conways (1997) / G & D (1990) / 100 Trivia of battleship Yamato (2010) 71,113 tm (69,990 tn. Left) 68,200 tm (67,123 tn. Left) 63,315 tm (62,315 tn. Left) 6,300 tm (6,201 tn. L.)
USNTMJ S-06-2 (1946) 72,809 tons 69,100 tons - -
Janusz Skulski: Battleships: axis and neutral battleships in World War II. (1988) for 1941
Yamato Museum
72,809 tons l. 69,100 tons l. 65,000 tons l. 6,300 tons
Displacement under test conditions in July 1944
Garzke, Dulin: Battleships: axis and neutral battleships in World War II. - 69,001 tm (68,009 tn. Left) - -
Shinano data through:
USNTMJ S-06-2 (1946) 71,890 tons 68,059 tons - -
Garzke, Dulin: Battleships: axis and neutral battleships in World War II. 71,890 tm (70,755 tn. Left) 68,059 tm (66,984 tn. Left) 62,995 tm (62,000 tn. L.) -

crew

A crew of around 2,500 seafarers was required to keep the ships fully operational. An exact number cannot be determined. As a result of the differences in the type and number of personnel-intensive anti-aircraft armaments and staff units carried along during the course of the war, the Musashi carried 2,399 men on their last mission, while there were 3,332 on the Yamato in April 1945.

Yamato-class ships

Yamato

The Yamato was launched in Kure in August 1940. She served mainly as a flagship in the Pacific War and was usually used behind the front lines. It was damaged by a submarine torpedo hit in 1943. However, it did not have its first real combat mission until October 1944 in the sea ​​and air battle in the Gulf of Leyte , where it was involved in the sinking of several small American aircraft carriers and destroyers. After the Imperial Japanese Navy was effectively defeated in 1945, the Yamato was sent on a suicide mission, Operation Ten-gō , in April . She was caught by American carrier aircraft on April 7, 1945 shortly after her departure and went down with most of her crew after a two-hour battle in which she had received at least thirteen torpedo hits and eight bombs.

Musashi

The Musashi was launched in Nagasaki in November 1940. Like her sister ship, she was not used offensively in the first half of the Pacific War. In 1944 she was assigned to the Japanese fleet after an increase in its anti-aircraft armament, which was to lead the decisive attack against an American landing fleet off the Philippines island of Leyte. Already on the approach the Japanese formation was attacked by carrier aircraft, which after a short time concentrated their attacks on the Musashi alone and continued for several hours, so that the battleship finally went down on the evening of October 24, 1944 after at least 19 torpedo and 17 bomb hits .

Shinano

The Shinano was laid down in Yokosuka in May 1940. At the end of 1941 construction was stopped and it was decided to convert the ship into an aircraft carrier. It was launched in October 1944 and was to be relocated to Kure for final equipment. On the way there she was hit on November 29, 1944 by four torpedoes from the American submarine USS Archerfish . The crew of the Shinano at that time consisted partly of civilian workers and seamen with insufficient training, and all hatches and fans between the watertight compartments were open, so that the penetrating water quickly spread into the compartments on the starboard side while the countermeasures initiated were closed started late, so that the aircraft carrier capsized and went down.

Ship 111

Ship 111 or hull 111 was the name of the fourth ship of the Yamato class . It is also known as Kii . It was named after the province of Kii on the Kii Peninsula . The Admiralty preferred this name for the completed ship. However, since the ship was never christened , this name cannot be considered valid.

The number 111 in the ship's name refers to the number of construction contracts awarded by the Imperial Japanese Navy . The ship was approved as the penultimate of its class by the Japanese cabinet in 1937. The keel was laid on November 7, 1940 in the Kure Kaigun Kosho (Kure naval shipyard) in the same dock as the one in which the Yamato was built. After it was around 30 to 40 percent completed, the war-related shortage of materials and the conversion of the Shinano forced the Admiralty to abandon the construction of the last two ships of the class. Moreover, the Admiralty had finally lost faith in battleships. Thus, work on the hull was stopped. The steel provided was used, among other things, for the conversion of the German passenger ship Scharnhorst, interned in Japan at the beginning of the war, to the escort aircraft carrier Shin'yō . The Hulk was in the docks until the end of the war. Since the Japanese were banned from building warships after the war, the ship's torso had become worthless. Since they did not want to wait until it was allowed to set up a self-defense fleet, as the Japanese Navy is called today, in which gigantic battleships like the Yamato class would no longer be needed anyway, the hull was towed out of the docks and scrapped. The material that was obtained was used for civil purposes. Essentially, this was the steel and the material of the finished armor. The fuselage itself was never equipped with weapons and never drove under its own power, so that the materials used for other purposes cannot be described in more detail here.

Ship 797

Ship 797 was mentioned in the imperial navy's newbuilding plans for 1942. It was planned as the fifth and last ship of the class, but its construction never began when there was no need for more battleships.

Super Yamato class

The Super Yamato class project was a program that was written in the fifth fleet construction program of 1941. In addition to the construction of new battleships, it also provided for the conversion of the five units of the Yamato class. After the completion of initially four Super Yamatos, these should also be converted to six 51.0 cm guns in three twin towers.

literature

  • Akira Yoshimura: Battleship Musashi: the making and sinking of the world's biggest battleship. Kodansha International, 1999, ISBN 4-7700-2400-2 .
  • David C. Evans, Mark R. Peattie, Kaigun: Strategy, Tactics and Technology in the Imperial Japanese Navy, 1887-1941. US Naval Institute Press, 1997, ISBN 0-87021-192-7 .
  • Janusz Skulski: Anatomy of the ship. The Battleship Yamato. Conway, London 1988, (3rd ed. 2000) ISBN 0-85177-490-3 .
  • William H. Garzke, Robert O. Dulin: Battleships: axis and neutral battleships in World War II. US Naval Institute Press, 1985, ISBN 0-87021-101-3 .
  • Gino Galuppini: Encyclopedia of Warships. Weltbildverlag, Augsburg 1995, ISBN 3-89350-828-7 , p. 93/94.
  • Roger Chesneau: Conway's All the World's Fighting Ships 1922-1946. Anova Books, 1997, ISBN 0-85177-146-7 .
  • Todaka Kazushige: The Battleship YAMATO and MUSASHI. 『日本 海軍 艦艇 写真 集 ・ 大 和 ・ 武 蔵』, ダ イ ヤ モ ン ド 社, 2005, ISBN 4-478-95054-7 .
  • Watanabe Yoshiyuki: Japanese Battleships. Gakken, 日本 の 戦 艦 パ ー フ ェ ク ト ガ イ ド, 2004, ISBN 4-05-603411-7 .
  • Takashi Amekura: Ship - Special Edition 720.戦 艦 大 和 100 の ト リ ビ ア - 100 Trivia of battleship Yamato, February 2010.
  • Kitaro Matsumoto: Design and Construction of the Battleships Yamato and Musashi. Haga Publishing, Tokyo 1961.

Web links

Commons : Yamato class  - collection of images, videos, and audio files

Evidence and references

Remarks

  1. promoted to Vice Admiral from 1941
  2. Other sources, such as Garzke and Dulin, give the value with up to 8%. The effect that was measured in the model test was given by a designer as 20%, see USNTMJ S-83, p. 23.
  3. Put hard rudder means turning the rudder to port or starboard as much as possible
  4. See the section on water displacement for the fuel supply .
  5. individual sources mention torpedo armament, but this is not supported by the specialist literature. So z. B. in Wätzig, p. 186, on the other hand z. B. not in silence. Numbers from eight to ten tubes are given in this context without any further explanation of the caliber or type of installation.
  6. The investigation report, which was written by experts of the US Navy in 1946 on the loss of the Musashi, according to the questioning of Japanese personnel who were involved in the development of the class, for the Musashi explicitly one, at the strongest point, only 400 mm (15.8 inches) thick belt armor, compared to 410 mm for the Yamato. So in report S-06-2, p. 17.
  7. The American aircraft torpedoes were filled with around 275 kg of torpex (= 415 kg of TNT). According to USNTMJ S-06-2 p. 10.
  8. in the USNTMJ report S-01-3 on page 45 the conversion from metric tons to British "long tons" is given as 1 metric ton = 0.985 long tons. According to this simplified calculation method, a "Long Ton" would not correspond to 1,016.047 kg, but 1,015.228 kg
  9. ↑ Described by the Japanese as standard displacement +75% of the amount of fuel, water and consumables, so in S-01-3 p. 17.
  10. 5,264.86 metric tons of fuel were specified in USNTMJ S-01-4 on p. 13, in this case in connection with a test run, so it must be assumed here that the tanks were not completely filled according to the test conditions .
  11. The values ​​of the three publications seem to differ only in minimal deviations in the rounding of individual values, unless otherwise stated.
  12. Fuel calculation according to Garzke and Dulin Battleships: axis and neutral battleships in World War II. P. 124.
  13. Skulski initially uses the unspecified unit "tons" on page 10, like US report S-06-2, but converts "tons" into "tonnes" on page 15 and multiplies the tons value by approximately 1.016047, so that "tn.l." can be assumed for his "tons".
  14. ^ Fuel calculation according to Janusz Skulski: Anatomy of the ship. The Battleship Yamato. 1988, p. 10.
  15. The Yamato was number 1 and Musashi was number 2. They were the first ships to be commissioned by the 1934 fleet building program. Shinano , because planned much later, was given the number 110 and the planned Kii the number 111, as they were only commissioned in 1937 after the planning for Yamato and Musashi had been completed.

Individual evidence

  1. a b c d e Type description on the official museum website of the Yamato Museum, PDF, viewed on January 6, 2011 ( Memento from June 27, 2011 in the Internet Archive )
  2. a b Takashi Amekura, Ship - 戦 艦 大 和 100 の ト リ ビ ア - p. 16.
  3. a b Harlow A. Hyde: Scraps of paper: the disarmament treaties between the world wars. Media Publishing, 1989, ISBN 0-939644-46-0 , p. 286.
  4. David C. Evans, Mark R. Peattie, Kaigun: Strategy, Tactics, and Technology in the Imperial Japanese Navy, 1887-1941. P. 296.
  5. ^ A b David C. Evans, Mark R. Peattie, Kaigun: Strategy, Tactics, and Technology in the Imperial Japanese Navy, 1887-1941. Pp. 295, 581.
  6. USNTMJ: Japanese Model Basins, S-83. P. 23.
  7. ^ Battleships: axis and neutral battleships in World War II. ISBN 0-87021-101-3 , p. 106.
  8. ^ Battleships: axis and neutral battleships in World War II. ISBN 0-87021-101-3 , pp. 109, 110.
  9. ^ Siegfried Breyer: Battleships and battle cruisers 1921–1997: International battleship building. Bernard & Graefe, 2001, ISBN 3-7637-6225-6 .
  10. ^ Battleships: axis and neutral battleships in World War II. ISBN 0-87021-101-3 , p. 108.
  11. USNTMJ: Surface Warship Hull Design, S-01-3. P. 27.
  12. a b Yoshimura: Battleship Musashi: the making and sinking of the world's biggest battleship. P. 41 and following.
  13. ^ HP Willmott: The Last Century of Sea Power: From Port Arthur to Chanak, 1894-1922. Indiana University Press, 2009, ISBN 0-253-35214-2 , p. 620.
  14. USNTMJ: Surface Warship Machinery Design, S-01-4. P. 8.
  15. a b USNTMJ: Surface Warship Machinery Design, S-01-2. P. 7 and following.
  16. USNTMJ: Boilers and Machinery, S-01-12. P. 7.
  17. USNTMJ: Surface Warship Machinery Design, S-01-4. P. 13.
  18. ^ After Garzke and Dulin Battleships: axis and neutral battleships in World War II. P. 124.
  19. a b c USNTMJ: O-45. P. 17.
  20. USNTMJ: Japanese Naval Guns, O-54. P. 9.
  21. USNTMJ: Japanese Naval Guns and mounts, O-47. P. 14.
  22. 46 cm on navweaps.com, viewed January 3, 2011
  23. USNTMJ: Japanese 18 ”Gun Mounts, O-45.
  24. USNTMJ: O-45. P. 58.
  25. USNTMJ: O-45. P. 50.
  26. USNTMJ: Japanese Naval Guns and mounts, O-47. P. 12 and following.
  27. 6 "on navweaps.com, viewed January 3, 2011
  28. USNTMJ: Mounts under 18 ”, O-47. P. 37.
  29. The 25mm / 60 Type 96 Model 1 MK on navweaps.com , viewed January 3rd, 2010
  30. USNTMJ: 1945-1946, O-50, Japanese Shipboard Rocket Launchers. P. 7, 8.
  31. USNTMJ: 1945-1946, O-09, Japanese Naval Rockets. P. 5 f.
  32. Various theories on the Musashi anti-aircraft armament , based on the article by Hans Lengerer in Warship 34 and others, viewed on January 6, 2010
  33. USNTMJ: O-30, Japanese Anti-Aircraft Fire Control. Pp. 13, 66.
  34. USNTMJ: E-01, Japanese Submarine and Shipborne Radar. P. 18.
  35. USNTMJ: E-01, Japanese Submarine and Shipborne Radar. P. 8.
  36. ^ Battleships: axis and neutral battleships in World War II. ISBN 0-87021-101-3 , p. 104.
  37. USNTMJ: S-06-2. P. 8.
  38. Article by Kent G. Budge on kgbudge.com , viewed January 3, 2010
  39. a b USNTMJ: Japanese Heavy Armor, O-16. P. 8.
  40. USNTMJ: Japanese Heavy Armor, O-16. P. 9.
  41. USNTMJ: Japanese Heavy Armor, O-16. P. 25.
  42. Article by Nathan Okun on combinedfleet.com , viewed Jan. 3, 2011
  43. USNTMJ: Japanese Heavy Armor, O-16. P. 46.
  44. ^ A b Battleships: axis and neutral battleships in World War II. ISBN 0-87021-101-3 , p. 94.
  45. a b USNTMJ: Surface Warship Hull Design, S-01-3. P. 40.
  46. USNTMJ: Surface Warship Hull Design, S-01-3. P. 43.
  47. USNTMJ: Japanese Heavy Armor, S-01-3. P. 45.
  48. USNTMJ S-01-4 p. 13.
  49. USNTMJ S-01-3 p. 42.
  50. ^ Conway's All the World's Fighting Ships 1922-1946. P. 178.
  51. ^ Garzke, Dulin: Battleships: axis and neutral battleships in World War II. P. 53.
  52. USNTMJ S-06-2 p. 10.
  53. ^ Janusz Skulski: Anatomy of the ship. The Battleship Yamato. 1988, p. 10.
  54. ^ Garzke, Dulin: Battleships: axis and neutral battleships in World War II. P. 125.
  55. USNTMJ S-06-2 p. 25.
  56. ^ Garzke, Dulin: Battleships: axis and neutral battleships in World War II. P. 79.
  57. ^ Yoshimura: Battleship Musashi: the making and sinking of the world's biggest battleship. P. 146.
  58. ^ Battleships: axis and neutral battleships in World War II. ISBN 0-87021-101-3 , p. 65.
  59. ^ Battleships: axis and neutral battleships in World War II. ISBN 0-87021-101-3 , p. 85.
  60. Article on the history of development by Michael Hansen on ibiblio.org, viewed on January 6, 2010