Already since the early 1930s, the Japanese, beginning with the expiration of the treaty deadline, began work on the design of new battleships. Initially, they were run within the framework of the treaty limit of displacement 35 thousand. tone. In 1934, however, in connection with the international sanctions imposed by the League of Nations on Japan for intervention in Manchuria, Japan has withdrawn from this organization and has decided to reject treaty restrictions. The new battleships were designed according to the Japanese rule at that time in the Japanese fleet that imperial ships must be faster and have better performance than their counterparts in the western fleets. Due to the inevitable advantage of the US fleet as a future adversary, it was decided to design the strongest „unsinkable artillery supercharged fire”, limited only by the capabilities of Japanese yards and ports. As a design assumption, it was assumed to equip 460 mm caliber guns and reach speeds of about 30 nodes.
The head of the design team was Vice Admiral Keiji Fukuda, the chief of advisers was a well-known Japanese shipyard admiral Admiral Yuzuru Hiraga. Between 1935 and 1936 there were 24 variants of the A-140 design of varying sizes and configurations, most of which were based on the British main propulsion and steam and diesel engine. The first and largest A-140 project assumes a displacement of 69,500 tonnes, a length of 294 meters on the waterline, a width of 41.2 meters, and SHP turbines with 200,000 turbines at 31 nodes. In the final A-140-F5 project, this capacity was limited to 65,000 tonnes, power to 150,000 tonnes. SHP and accelerate to 27 nodes.
The initial nature of the ships was set in October 1935 (Nine Chapters 460 mm in three towers, two in the bow). Selected A-140-F5 preliminary draft was published July 20, 1936, Final plans in March 1937, Deciding on turbine propulsion. For shipbuilding, shipyards had to be upgraded; Yokosuka and Sasebo built new large docks. A special „Kashima” ship was built to transport and maintain battleships.
Details of the construction of this type of ship were surrounded by total mystery. The ramp in Kure on which the Yamato was built was covered with a roof to shield the ship from observation from a nearby hill, the Musashi ramp in Nagasaki harbor was tightly covered with hemp ropes, and the police also tried to limit the visits of foreigners to these cities. Moreover, some of the engineers working at the site, and later part of the crews and naval officers also did not know their full characteristics, primarily armament and armor. For the sake of secrecy, the 460 mm caliber ammunition was called the „40mm special ammunition”. The construction of both ships was strongly opposed by Japanese commander Admiral Isoroku Yamamoto, who emphasized the development of maritime aviation; This undertaking was pushed against his will (to say that „battleships will be as useful to Japan in modern warfare as samurai sword”).
Originally intended to build five ships of this type. Construction of the first of the battleships, „Yamato”, is provided for in the Third Ship Exchange Program of 1937. Both ships were launched in 1940, service was first entered „Yamato”, December 16, 1941, and „Musashi” after the Battle of Midway in June 1942. . Eventually only two of the above-mentioned battleships were completed, and in December 1941, after the attack on Pearl Harbor, work on the rest of the crew was discontinued.
Both ships were colossal: their standard displacement was 65 thousand tons, and the full 72.8 thousand. The trenches were 263 meters in length, 36.9 in width, and 8.9 meters in draft (10.2 with bow).
The mystery proved effective and until the end of the war the Americans did not know the characteristics of the battleships. The Naval Intelligence Office published estimates of the ship’s standard displacement of 42-45 thousand tons and armament in 9 guns of 406 mm, although some officers suspected that the armament could actually be a 457 mm caliber. The official data was the basis of erroneous estimates, suggesting that, for example, South Dakota-type battleships could successfully fight Yamato at a range of 14-21,000. Without compromising, while in reality alone would have little theoretical chances in the clash. Also the look of the Japanese battleships was a mystery and their first good shots were only taken on the occasion of the sinking of „Musashi” on October 24, 1944.
The first sank „Musashi” – sunk him on October 24, 1944 during the Battle of Leyte, Sibuyan on the American airstrips from „Cabot”, „Enterprise”, „Essex”, „Franklin” and „Intrepid” aircraft. Even with 20 torpedo hits, 17 bombs and 18 close bombs (bomb hits had a marginal impact on the readiness of the battleship), it has remained on the surface for a long time. „Yamato” shared the fate of his „brother” and sunk, half a year later, during a Ten-Go operation after a massive assault on US surface aviation aircraft carrier TF 58, hit 11-13 torpedoes (two probable hits) and 8 bombs. For its sinking less torpedo was needed, as the Americans drew conclusions from the attack on Musashi, and most of them – 9 and probably two more – hit the left side, causing asymmetrical flooding and loss of stability. The date of sunk Yamato, April 7, 1945 at 14:23, is often considered to be the end of the battleship era, which is debatable – in both cases a single, weakly armed anti-aircraft gun battleships had to repel the attacks of hundreds of state-of-the- fleet carriers.
Battleships of the type Yamato and the aircraft carrier remained „Shinano” with battle large units still long after the war, and the situation changed only in the moment of inserting the American shock USS aircraft carrier into the service „Forrestal” (displacement full of over 80 thousand ton) in 1955.
Arming these ships was impressive: constituted main artillery nine department of unparalleled calibre of 460 mm arranged in three three partition towers; for comparison biggest is acting ship’s had western states calibre of the at most 406 mm. Their maximum sonorousness was 42 kilometres. Bullets weighed 1460 kg – almost one and a half times more than previous Japanese department of calibre of 410 mm, and przebijalność of armour was about twice as bigger. Apart from an anti-tank shells and demolishing, to department of the ones also anti-aircraft shells were drawn up (shrapnel shells), for conducting the barrage, with a set time fuse. Alone the tower only weighed 2774 tones, i.e. more than a big destroyer.
The additional weaponry constituted at first twelve the department of 155 mm of four towers and anti-aircraft artillery having twelve universal the department of calibre of 127 mm and 24 quick-firing cannon of calibre of 25 mm of Type 96. Towers department of 155 mm came from heavy cruisers of the type Mogami, after rearming them in of cannon of calibre of 203 mm. The distribution gave them the department of 155 mm big angles of the circular fire – one each of tower on the beak and the stern, too and above towers of main artillery and one each of tower on every of sides on the waist (side towers later were removed). They were going to use cannon 155 the mm at anti-aircraft targets, but weren’t suitable well for this function due to the moderate angle of raising, the rate of fire and the speed of the turnover of tower (5 ° / s).
In the course of the war arming ships was modernised, reflecting the growing threat on the part of aviation – for the first time at the end of 1943, when they liquidated 6 from 12 department of calibre of 155 mm to the benefit of anti-aircraft artillery. To their place they were planning installing 12 universal department of calibre of 127 mm, however it was only made on „Yamato”, because for „Musashi” was missing department and after all didn’t receive them. On both ships an anti-aircraft light artillery was reinforced adding cannon of calibre of 25 mm, however which turned out to be completely ineffective, for and at the end wars actually constituted only an unnecessary burden. After this modernization „Yamato” was armed in 9 department of 460 mm, 6 department of 155 mm, 24 universal 127 mm is acting and 36 (autumn 1943), 98 (May 1944), and finally of 113 cannon of 25 mm (July 1944). „Musashi” had 12 the department of 127 mm and the substantial amount of plots of 25 mm.
In 1944 he underwent the second modernization only „Yamato”, „Musashi” earlier was sunk. The modernization consisted in reinforcing anti-aircraft artillery – the number of quick-firing cannon rose to 152.
For developing data among others rangefinders were used for soaring – the 15-underground stereoscopic rangefinder on the bow top floor extension was the biggest device of this type installed on battleships. The quality of Japanese optical devices was very good, however alone dalocelowniki were already a little bit worse than American, whereas artillery calculators similarly to the automation, stabilization (generally, the entire control system of the fire) were leave a lot to be desired. Battleships of the type Yamato were equipped with the most modern radioelectronic devices available in Japan however which stood on the much lower level of development, than American. With autumn 1942 „Musashi” received the radar of air and surface observation Type 21 Kai-1, and „Yamato” Type 21 Kai-2. At the beginning both ships received 1943 for two one-decimetre radars of surface Type 22 observation, but with autumn 1943 „Yamato” Type 21 Kai-3 radar. Additionally in 1944 both received for two Type 13 radars. They then were also equipped in hydrofony for the detection
In the stern they found ships oneself two catapults for seaplanes which ships took to 4 (a possibility of transfer operation 7 existed) and podpokładowy hangar.
With consecutive element affecting by force battle of these ships passive protecting against effects direct hits was, that is simply plating. On these ships it decided over 1 / 3 of weight of the entire ship and was extremely fat. The plating was designed according to the outline adopted in the structure of battleships „all or nothing” (all or nothing), with the central armoured citadel enveloping the fitness room and cartridge chambers department beneath towers. The main side armoured lane on the waterline had a thickness of 410 mm, but a thanks for deviation about 20 ° outside, 584 mm corresponded to the vertical plate with regard to the AP bullet of calibre of 460 mm of c 20 thousand launched from distance of metres. He was made from tempered powierzchniowo VH, i.e. Vickers Hardened stood (by the over 10 per cent weaker with regard to the protection against AP bullets from the American armour hardened powierzchniowo of type and). In spite of the flimsiness of fabric, the thickness did its job and as a result the side armour was able to withstand hitting missile 18,
An inside armoured deck of the thickness of 200-230 mm, closing the citadel built by side lanes from above constituted the horizontal plating (together with other thin decks, the thickness of the horizontal protection was 240-293 mm). Crosswise barriers closing the citadel at the front and, about the complicated shape, were behind thickness of 270-350 mm. Beak, stern, sides above the side strip and top floor extensions weren’t armoured. Outside the citadel, protected rooms of steering machines of the main and support helm were a thick armour (up to 300-360 mm all over sides, 200 mm from above).
Towers of main artillery had an armour 650 mm thick at the front, 250 mm from sides, 270 mm from above and 190 mm at the back. Wimples of towers had a thickness by 380 mm from the back up to 560 mm all over sides. The conning tower was also armoured with plates of the thickness of 500 mm. Towers of artillery of 155 mm were lightly armoured with armour of 50 mm, their high wimples – 75 mm. The fact that magazines of the ammunition were armoured was one of unique features of the scheme of the Yamato plating with armour of 50-80 mm even from the side of the bottom, in the case of the explosion of the mine.
In spite of such a huge plating they didn’t avoid a fault in the design, with which the insufficient endurance of connecting the upper and bottom belt armoured, drawn aside was under other angle. For this reason the bottom armoured belt too poorly was attached and castle przeciwtorpedowe had a too low susceptibility to elastic strains. Unlike other battleships, protection system przeciwtorpedowej was based only on an quite thick internal armoured, constituting belt main fence off przeciwtorpedową and on empty ranges from the outside and inside, without ranges filled up with fuel, exchanger or water. As a result of the adopted concept and the described defect, he was, as it turned out in practice, little effective against explosions of torpedoes. Yet, ships were very heavy-duty for blows, thanks to their plating, the size and the internal division (altogether had 1147 watertight chambers).Direct hits of torpedoes which overcame the protection przeciwtorpedową, caused flooding only outside ranges in general and ships long watched, and thanks to controlled sinking ranges on the other side, long kept the stability, although simultaneously into this way a ship was being deprived of the combat readiness. Leaving to a lot ranges was other significant fault about the significant volume without any cover outside the armoured citadel, peculiarly on the beak (direct hits of torpedoes in this region were particularly severe for „Musashi”).
None of ships never struggled with American battleships, so their plating wasn’t tested in the action, were sunk by aviation. Aircraft bombs triggered only surface damage, but ships were sunk by torpedoes.
Description of the hull
The hull of ships was exceptionally wide how to your dł 7 invite what was caused with aspiration to holding the fitness room without unnecessary extending the armoured citadel. Because of that lines of the body weren’t optimum for developing high rates of speed. Partly using the bow pear improved the situation. Ships were smooth-deck, but the upper deck had a characteristic diffraction in part bow, designed for the weight reduction at keeping the seaworthiness (because of that bow towers were put in a little bit more low, than by the simple deck). On very stern the deck had a dodge in the area of air catapults.
The fitness room consisted of four teams put in the body longitudinal by oneself consisting of three boiler rooms and one engine room in watertight periods. The fitness room didn’t cause exploitation problems, but due to desire for ensuring the reliability was efficient little towards mass (pots worked under pressure 25 kG/cm 2). It felt drawn behind itself to the great fuel consumption and the restrained reach of ships what was their defect, especially in the difficult situation of fuel Japan and influenced low intensity of their operation.