Nagato class
| Nagato class | |
|---|---|
_wmplayer_2013-07-17.jpg)
|
|
| Overview | |
| Type: | Battleship |
| Units: | 2 |
| Predecessor class: | Ise class |
| Successor class: | Tosa class |
| Technical data (original planning) |
|
| Displacement: | Standard: 33,800 t |
| Length: | over everything: 213.40 m |
| Width: | 29 m |
| Draft: | 9 m |
| Speed: | Peak: 26.4 kn |
| Crew: | 1400 permanent crew |
| Range: | 5500 nautical miles at 16 knots |
| Drive: | 4 screws over 4 shafts |
The Nagato class ( Japanese 長 門 型 戦 艦 , Nagato-gata Senkan ) was a class of two battleships of the Japanese Empire that were used in World War II . It was the last Japanese battleship class to enter service in the following 15 years after construction was halted by the Washington Naval Treaty in 1922.
Development history
Skagerrak
The Imperial Japanese Navy had already started planning a new class of battleships in 1916. Based on the plans of Admiral Yuzuru Hiraga, the findings from the Skagerrak Battle of June 1916 also flowed into the considerations soon after they became known . The British Queen Elisabeth class was now to be surpassed by the Japanese design, and it was therefore decided to use 16-inch guns. The first-time use of such heavy guns would make the previous practice of six turrets, which had been used in the series of the Fusō class and the Ise class , superfluous; four towers with two guns each should be sufficient as the main armament. The weight saved in this way and innovative machinery should allow a speed of over 26 knots and make the Nagato class one of the fastest battleship classes of its time.
The changes in the area of protective systems, which were made with new developments worldwide based on the experience of the Skagerrak Battle, also affected the Japanese plans, and the concept of "all or nothing" armor was supplemented by additional protective measures. Instead of only protecting the vital areas of the ships with thick armor plates, protection was also concentrated on these systems, namely the ammunition chambers and engine rooms in the hull and the turrets and the command post on deck, but at the same time the engine rooms were segmented to avoid all of them in the event of damage To lose propulsion systems due to the ingress of seawater.
Washington
During the Washington Naval Conference from November 1921 to February 1922, the Nagato class became the cornerstone of Japanese negotiation. While Great Britain pushed for a caliber limit of 15 "(38 cm), Japan insisted on officially 16" (although 16.14 "(41 cm) guns were actually used) based on the already completed Nagato and the final Mutsu . and 35,000 tons of water displacement. It was only after tough negotiations that the Japanese delegation under Admiral Katō finally managed to keep the two units of the class, albeit only after making appropriate concessions to the USA and Great Britain, with the latter having to keep the HMS Hood (42,000 tons).
Propulsion systems
The Nagato class was the first Japanese battleship design to use heavy oil as the main fuel in 15 steam boilers . On the other hand, coal was only used in 6 boilers designed for mixed firing. The fuel reserves stored for this boiler combination were around 1,600 tons of coal and 3,400 tons of heavy fuel oil. The top speed was around 26.7 knots.
Four large, new Kampon boilers and six smaller ones that had been redesigned were all designed for oil firing and replaced the old boiler systems in 1936. The second chimney behind the bridge has been removed. A large weight saving was achieved, which was more than offset by the weight of the additional armor elements that were also retrofitted in 1936. The draft increased by about 50 cm and the top speed dropped to 25 knots.
Four turbines, two of which were high and two low pressure turbines, transmitted the drive energy to four shafts. These Gihon or Kampon type turbines were the first Japanese in-house developments, while previously they had relied on the models produced under license by Parsons or Curtis-Brown. The power generated by the four installed turbines was around 80,000 WPS. Attempts had been made to build modern turbines with rotors made from one piece, but one of these Nagato turbines had a blade torn off during a test run , and the attempt was abandoned.
The engine rooms were given a central control station within the hull in front of one of the boiler rooms, which enabled the chief engineer in charge to monitor all relevant displays in a separate, cooled room and to communicate with the individual engine and boiler rooms by telephone.
Four generators for power supply were available, two of them aft of the engine room and two in front. The system generated a voltage of 225 volts DC for the consumers in the ship . Every important consumer (control, turrets, communication) had two connections for the power supply, which were connected to two separately functioning circuits, so that if one circuit failed, the other could be switched. For emergencies, there were also two sets of batteries, one for the supply in the aft and one for the forecastle. Another set of 220-volt batteries was located next to the steering gear room in order to supply the rudder control motors in an emergency.
Armament
Main artillery
The main armament consisted of eight 41 cm L / 45 guns, which were set up in four twin towers along the longitudinal axis of the ships, two towers on the fore and two on the stern. Each tower weighed around 1100 tons and was operated by a steam hydraulic pump that achieved an output of around 630 hp. The type of gun used was developed in 1914 (model "3rd year" according to the Taishō era ) and could shoot a 1,000 kg grenade up to 38 km. The rate of fire was 1.5-2 rounds per minute.
During the modernization of the ships in 1936, these towers were removed and replaced by the more modern versions from the scrapped Tosa class . These were largely identical, but had a maximum tube elevation of 43 ° instead of the previous 26 °. Two towers, tower “B” and tower “C” were each equipped with a basic device that could be used to measure distances.
Inside each tower, both guns were divided by a shatterproof longitudinal bulkhead. A similar bulkhead divided the cargo compartment in the lower part of the towers. A gunner sat in a soundproofed area at the rear of each tower. The speed with which the towers could be rotated horizontally was up to 3 ° per second; the speed at which the pipe elevation could be changed was about 8 ° per second.
Two of the projectiles used deserve special mention: The type 91 armor-piercing projectiles, unlike comparable weapons in other navies, were designed to continue their trajectory under water. The basic idea was that the grenades that hit the water shortly before a target would maintain a stable trajectory even underwater and ideally explode below the belt armor on the poorly protected underside of the target. Both the shell of the bullets and the cap that sat directly on the grenade have been optimized for this purpose.
Another special feature of the ammunition was the Model 3 incendiary cluster munitions for air defense, which was introduced relatively late in the war. Here the 41 cm grenade was a submunition carrier that, similar to a cluster bomb , broke apart after a preset time and released many dozen 25 × 90 millimeter tubes, each of which burned for several seconds at 3000 ° C as it fell towards the ground.
Approximately 180 shells of ammunition are assumed for each magazine.
Secondary artillery
As secondary armament, 20 14 cm L / 50 guns were installed in casemates, 10 each on port and starboard, which, unlike the Ise class , are not exclusively in the hull, but 3 each on port and starboard in a superstructure above the Main decks set up. In 1936 two 14 cm guns were removed. The guns had the additional identifier "3. Year ”(according to the Taishō calendar ) as an indication of the year of development. Each weapon had a protective shield and a simple visor and was loaded by hand and could fire between 5 and 10 rounds per minute, depending on the performance of the operating team. With the HE shells weighing around 38 kg, a range of up to 20 km was possible. The usual equipment also included armor-piercing projectiles with ballistic hoods and flares.
Air defense
Four individual 7.62 cm L / 40 anti-aircraft guns, officially classified as 8.0 cm, which were initially set up in open mountings on deck, were replaced from 1932 by four 12.7 cm L / 40 Type 89 twin anti-aircraft guns . These could attack targets at low altitudes (up to 10 ° rise in the pipe) up to 15 km away and targets at high altitudes (up to 75 ° rise in the pipe) up to 10 km away. The anti-aircraft grenades used disintegrated after the previously set time, creating a 15-meter fragment radius. Each gun reached a rate of around 8 rounds per minute. The ammunition, consisting of a projectile with a metal cartridge, was transported from the ammunition chambers to the vicinity of the guns by an elevator and then carried by hand by three loaders to the right side of the mount, where the time fuses for the grenades were set. The guns were then loaded by hand and fired by the gunner, who sat on the left side of the gun carriage, by pressing a pedal. The carriage could only be moved with the help of electric motors. The electro-hydraulic system developed a power that could swivel the 25-ton carriage to the side by 6 ° per second and change the pipe elevation by 12 ° per second.
, The slight air defense at close range was based, as with most Japanese ships of the time on 25-mm automatic cannon . The weapon was based on the design of the French Hotchkiss machine guns and was built for the Navy in Yokosuka from 1936 . It fired projectiles weighing 250 grams at a muzzle velocity of around 900 meters per second with an effective range of 3000 meters. Based on the 15-round magazines, it only had a rate of about 110 rounds per minute. The individual cannons were grouped in Type 96 triplet or twin mounts or stood individually.
The Type 96 triplet mount was theoretically designed for remote-controlled aiming and firing. Since the necessary piping systems were not installed in some of the guns, aiming was done with a simple sight and straightening with two hand cranks. One pedal was used to pull the triggers of the two outer cannons, another pedal released the trigger of the middle cannon.
There were 16 triplet and 10 twin mounts on the Nagato (in its last state of construction as an active warship from summer 1944), plus 28 additional single mounts. Each triplet mount had an operating team of three soldiers and a loading team of two soldiers per tube, so nine men in total. The single mounts were operated by three men each.
Torpedoes
The eight 533 mm torpedo tubes that the ships had originally received were also removed in 1936 as part of the renovation work. The tests carried out on the Tosa had exposed the torpedo rooms with the weapons stored in them as a clear weak point, and it was recommended either to remove the rooms or to protect them with massive armor.
Armor and Structural Protection System
Based on the results obtained through various series of tests with fire attempts on the Tosa , the protection system of the other Japanese battleship classes was also revised.
Structural protection
The structural protection against torpedo hits consisted of bulges on the sides of the ship, which were retrofitted in 1936. The original protection had only consisted of the expansion space provided by the fuel tanks, which were located between the outer hull and the torpedo bulkhead. The new torpedo bulges increased the possible expansion space in which a torpedo explosion could spread without endangering the engine rooms to about 6.5 meters. The lower part of these new torpedo beads contained alternating a fuel bunker and an empty, watertight compartment, while the upper part consisted of two further watertight compartments.
The fuel in these outboard tanks was usually used up first, but could also be pumped into the inner tanks. The previously empty sections in the upper part of the bulges were filled with steel pipes ("crumple tubes") in 1941 in order to achieve better shock absorption in the event of a torpedo explosion at the bulge.
Armor
Even before the modernization of both ships, the class had a double ship's bottom that contained fuel tanks. In 1936 an additional armor plate was riveted under the lower floor. It did not extend over the entire width of the ship, but extended from the outer hull inwards to just over the outer longitudinal bulkhead of the boiler rooms and was almost 40 mm thick. The rest of the lower floor was made of ordinary steel. The continuous ship floor inside, on the other hand, was made of around 12.5 mm armor steel.
The vertical belt armor of the Nagato class was 30 cm thick at its widest point and lapped to a thickness of about 15 cm at the bottom, which means that it was a continuous armor plate, but its thickness decreased in the lower part. It extended over around 63% of the ship's length, while it was significantly shorter for comparable ships. Towards the ends of the fuselage, it thinned out to about 100 mm.
Far more armor than other designs of the time was used for horizontal protection. In addition to the armored top of the citadel (armored deck), the class received an armored tween deck and an armored weather deck, which protected the 14 cm guns in their casemates from steep fire and aerial bombs. The top of the superstructure, which was located between the bridge tower and the turret "C", was barely armored with only around 6 mm of steel.
This horizontal armor protection for all areas between the main gun turrets increased dramatically in the course of the modernization work on the class from 1936 onwards, as the decks received additional layers of armor steel in addition to their existing armor. The particularly critical area above the ammunition chambers received up to 12 cm of additional steel armor.
From 1936, the turrets of the main artillery were protected on their front with around 350 mm thick armor plates, on the top with up to 230 mm. The barbeds , i.e. the cylindrical structures below the towers through which the ammunition was transported, were protected all the way to the armored deck with 290 mm armor steel, which in some places grew up to 325 mm thick.
The command post, i.e. the small command center in the bridge tower immediately behind tower "B", from which the most important ship systems could be controlled in an emergency, had a protection of 340 mm steel. The rest of the bridge structure was only protected against splinters and small-caliber gun fire, or it had only sheet metal cladding to protect against the weather.
The armor steel used for most of the armor was of the "NVNC" (New Vickers, Non Cemented) type, which was not post- hardened . The belt armor, on the other hand, was case hardened, but was also produced using the manufacturing process of the British Vickers-Armstrog group and was therefore called "VC" (Vickers, Cemented). The NVNC armor elements were more flexible than the VC armor and, due to the lack of a work step, they were also cheaper to manufacture and process. The VC armor, on the other hand, was more able to repel shrapnel and direct hits without damaging the ship.
rating
The hulls of the Nagato- class were made of steel plates that, like the bulk of Japanese warships, were riveted and not joined by welds. The connections between the armor plates formed a weak point. While the connection efficiency of modern battleships such as the Bismarck- class was estimated at around 85%, the efficiency that American scientists found for the Nagato-class after the war was only around 65%. This increased the risk that armor plates could withstand an impact, but at the same time tear the connections to the neighboring plates.
The increase in the width of the ship due to the bulges forced the hulls to be lengthened by almost 9 meters in order to maintain the ratio of width to length at a favorable level. The heavy additional armor that was added during the modernization work increased the draft to 9.70 m. In contrast to previous Japanese battleships, the Nagato class also wore a curved clipper bow.
The ship-class belt armor was not the most powerful vertical protection system of its time. The German Kaiser class from 1912 already had a 35 cm thick belt armor. However, the Nagato-class armor was never exposed to heavy shell hits. Only a few smaller aerial bombs hit the Nagato during the war , but none of them penetrated the armored deck above the citadel or the intermediate deck. The pressure and heat waves of the two atomic bomb explosions that hit the Nagato after the war in Bikini Atoll were also unable to destroy the armor protection of the hull.
Reconnaissance and fire control
The Nagato class was initially only equipped with various observation and fire control systems, which were composed as follows:
Optical systems
The main rangefinder, with a base length of 10 meters, determined the distance for distant targets against which the main artillery of the ships could then be used. It was, atypically, mounted below the battle bridge in the bridge structure. This meant that it could not be rotated 360 ° around its own vertical axis, as the support structure of the battle bridge above was in the way. Therefore, the entire range finder was placed on rails on which it could be moved in a circle around the support structure.
The main control unit of the type 94 (Hoi-ban) was housed in a weather-protected dome on the top level of the bridge tower, above the battle bridge, and consisted of three 15 cm observation telescopes, a computing unit and a communication system. The operating team for the main control unit consisted of five seamen and one officer. This control device directed the fire of the four heavy turrets.
A Type 92 (Sokuteki-Ban) observation device was set up on a platform about halfway up the bridge tower, which collected data on the course and speed of an opposing ship. It was similar in structure to the main control unit, but in addition to a telescope, it also had an inclinometer and a mechanical calculating machine.
The data from the various optical rangefinders (later also from the radar), the main control unit and the "Sokuteki-Ban" computer were initially passed on electrically to the fire control center. The fire control center was located in the fuselage, below the bridge tower, protected by the armored deck. The incoming information was first checked for its probability so that the data of destroyed or damaged rangefinders could be sorted out. A type 92 computing device (Shageki-ban) was then programmed by hand with the information and processed further. He was served by seven men and one officer. Taking into account wind speed, own course, own speed, probable course and probable speed of the target and the flight time of own grenades, the computing device then determined the fire control solution for the guns and transmitted it back to the control unit.
The crew of the Type 94 control unit could then make readjustments to the values, for example to compensate for the rolling movements of their own ship, and then passed the information on electrically to the turrets.
The 14 cm guns of the secondary artillery were also guided by a Type 94 control device, but this only had two weaker telescopes with 12 cm lenses. At the level of the bridge tower, which housed the Type 92 "Sokuteki-Ban" for the heavy artillery, two smaller versions of the Sokuteni-Ban were also housed on port and starboard platforms, which determined the data on the location of the target for the secondary artillery.
Both systems were connected to their own Type 94 (Shageki-Ban) fire control computer in the fire control center, which was operated by five sailors and one officer. In contrast to the main artillery, the fire control center here transmitted the calculated values directly to the guns, without going through the control unit, so that a faster update of the data for fighting the more manoeuvrable targets at close range was possible.
Both the control devices for the main and secondary artillery were designed redundantly, so that if the control devices in the bridge tower failed, the fire control data could also be delivered to the control center and the guns from systems on the platform on the rear mast.
The heavy air defense relied on its own, faster control system, consisting of rangefinders with a base length of 4.5 meters and control devices of type 91 (Kosha-Soshi), which were each mounted together on two platforms on both sides of the chimney.
The stereoscopic rangefinder with a base length of 4.5 meters provided a magnification of up to 24 with a viewing angle of 1.5 ° via two 48 mm lenses at the outer ends of the boom arms . The entire structure of the rangefinder could be rotated around its own vertical axis and the lenses could be adjusted horizontally using the arms.
The Type 91 control unit, which weighs around 3 tons, required eleven men to operate. It was an optical total station , which, in combination with a rotary meter , determined the course and speed of the targets via observation slots in the cylindrical casing on the top and then, together with the data from the independently functioning range finder, the information on the horizontal and vertical straightening angle, as well as the Data for setting the detonators on the grenades transferred to the 12.7 cm anti-aircraft guns. The system was able to provide data for combating air targets or for surface targets at close range. The observation telescopes in the control unit could be swiveled upwards from −15 ° to an angle of + 90 ° and were mounted on three axes. The commanding officer looked through observation binoculars in a small dome on the top of the housing and selected the targets for which the other staff then determined the fire control data.
The type 91 control unit was replaced during the war by the similar type 94 control unit, which was easier to use and could also process distance information from the radar systems. The type 94 control unit was built by the company Nippon Kōgaku Kōgyō Kabushikigaisha .
The heavy main artillery of the Nagato class could also be used for air defense in the later course of the war. With the 41 cm standard grenade Mod. 3 incendiary cluster munitions, a barrage should be fired against airmen. In order to be able to fire this ammunition with pinpoint accuracy, the fire control system described for the main artillery was not sufficient, so an additional computer was installed in the fire control center. This system was controlled by an operating team of nine sailors and determined the aiming angles of the cannons and the range settings for the dismantling fuses of the anti-aircraft grenades, which were then transmitted to the top-level gunners in the towers.
The light air defense was controlled by Type 94 (Kosha-Sochi) control devices. Although the Type 95 system had already been developed to be coupled with 25 mm automatic cannons and to remotely control the motors for horizontal and vertical aiming of the cannons, based on a system based on the inventions of Ward Leonard , the control of the mass of the Nagato-class 25mm weapons to the simpler Type 94 system.
Two 1.5 meter rangefinders with splinter protection and two 1.5 meter rangefinders without protection were available on the sides and at the rear end of the main bridge for alternative determination of target distances in the event that other rangefinders failed.
Reconnaissance aircraft
For test purposes, a simple departure deck was built on the roof of tower "B" as early as 1925, but it was dismantled again after a short time. For reconnaissance at great distances, a catapult for the launch of seaplanes was not installed between tower "C" and the main mast until 1933. It was combined with a maneuvering deck for aircraft, similar to that on the Kongō class . A rail system was installed on the deck that allowed the aircraft to roll by hand from their parking positions to the catapult. Three E8N1 aircraft were carried on this deck from 1938 onwards, but their importance as a reconnaissance aircraft declined sharply in the course of the Pacific War . To get the aircraft back on board, a crane was mounted on the side of the flight deck.
radar
The class was subsequently converted to use the newly developed radar systems : A Type 21 (Gō Dentan) was planned. In May 1943 the antenna for the system was installed on the top platform of the bridge tower, behind the Type 94 main control unit. The Type 21 (actually an abbreviation for Type 2 Model 1) was developed to search for air and surface targets.
Two type 13 radar systems, each with a Yagi-Uda antenna , were installed on the support structure of the aft mast in June 1944. The Type 13 (actually an abbreviation for Type 1 Model 3) was a radar that had been developed to search for air targets and was more powerful than the Type 21 device in this discipline.
A Type 22 radar system, consisting of two sets, was installed on both sides of the bridge tower and retrofitted in June 1944. Both systems were mounted on small platforms on the sides of the main rangefinder platform. The type 22 (type 2 model 2 modification 4) was a system for searching for surface targets that was based on magnetron technology and had a horn antenna each as a transmitter and receiver. It could locate a large ship target, such as a battleship, at a distance of 25 km with an accuracy of around 100 meters, which was sufficient for directing heavy artillery.
rating
The type 92 (Shageki-ban) calculating machine for the fire control of the main guns was based on developments by the British company Barr and Stroud from the 1930s, which were copied by the Aichi watch factory and adapted to the requirements. Unlike modern systems used by other navies in World War II, the machine did not have any devices for tracking the course, speed and distance of more than one target ship at the same time, which made it difficult to quickly switch between different targets. In addition, many work steps had to be carried out manually, which made the system labor-intensive and the calculations error-prone.
The air defense fire control system suffered from numerous problems. Initially, it was originally developed for slow-flying targets, which is why a lot of data had to be entered into the computer, which increased the accuracy of the fire control solution minimally, but only had secondary priority (e.g. drift of the target) and thus the processing time up to Determination of a guideline value greatly extended. The separation of the rangefinder and the arithmetic unit could lead to confusion, as different data for input into the computer were called from several sides to a communications soldier on the computer, who then assigned them. In the case of attacks from several aircraft, it was also difficult to select a specific target, as the command officer and operating team of the rangefinder tended to track different targets through their respective vision devices and accordingly report contradicting data to the calculating machine. This problem could only be resolved later by installing an observation dome for the officer in the roof of the range finder. The altitude and speed data that were later provided by the Type 21 and Type 13 radar systems were not accurate enough for fighting enemy aircraft in the dark.
In combination with the inefficient weapons, the defense performance of the air defense system is generally rated as poor and largely ineffective.
With the exception of the 10 cm Type 22 radar, the built-in radar systems were consistently less accurate and more unreliable than the Allied systems. The Type 22 could never reach its full potential as the Japanese did not have PPI (Plan Position Indicator) screens that would have made it easier for the operator to separate different signals.
| Nagato radar systems (American MK.8 system for comparison) | ||||
| designation | Type 21 | Type 13 | Type 22 | US Mk 8 |
| wavelength | 1.5 meters | 2.0 meters | 0.1 meters | 0.1 meters |
| power | 5 kW | 10 kW | 2 kW | 20 kW |
| Range (single air target) | 70 km | 100 km | 17 km | - |
| Range (large ship target) | 20 km | - | 24 km | 50 km |
| Installed on the Nagato class | 05/1943 | 06/1944 | 06/1944 | - |
Distinguishing features
Mutsu and Nagato are usually difficult to distinguish in photographs, as the minimal deviations in the positioning of equipment on the bridge tower or the bollards are difficult to identify.
Only later pictures showing a ship of the Nagato class with additional anti-aircraft cannons can one assume the Nagato , as the Mutsu had not received this upgrade before its sinking. The same applies to the radar systems of types 21, 13 and 22, which the Nagato carried from May 1943 and June 1944, respectively.
Nagato-class ships
Nagato
The Nagato was laid down by the naval shipyard in Kure in August 1917 and launched in November 1919. She was mainly used as a lead ship in the Pacific War and was only involved in direct combat operations with opposing surface ships during the Battle of Leyte in October 1944 . At the end of the war it was anchored in Kure as a floating anti-aircraft platform due to lack of fuel and ultimately confiscated by the Americans. It was then used as a target ship and went down in Bikini Atoll on July 29, 1946 after an atomic bomb test .
Mutsu
The Mutsu was laid down by the Yokosuka naval shipyard in June 1918 and launched in May 1920. In the Pacific War she was mostly used behind the fighting parts of the fleet. Among other things, she carried out security tasks for Japanese aircraft carriers in the battles of Guadalcanal . On June 8, 1943, an explosion in one of the magazines below the main guns, the cause of which has never been fully clarified, tore it in half in the bay off Yamaguchi and sank.
Evidence and references
Individual evidence
- ^ Battleships: United States battleships, 1935–1992, William H. Garzke, Robert O. Dulin, Publisher: US Naval Institute Press, 1995, ISBN 1-55750-174-2 , p. 3
- ↑ Japanese Foreign Policy 1869-1942: Kasumigaseki to Miyakezaka, Ian Nish, Verlag: Routledge, 2002, ISBN 0-415-27375-7 , pp. 139 and 140
- ↑ REPORTS OF THE US NAVAL TECHNICAL MISSION TO JAPAN 1945-1946, S-01-11 Characteristics of Japanese Naval Vessels-Article 11, Main and Auxilary Machinery, p. 15
- ↑ [1] navweaps.com, viewed June 10, 2010
- ↑ [2] Summary of the technical data on nps.gov, viewed on June 3, 2010
- ^ Battleships: axis and neutral battleships in World War II, William H. Garzke, 1985, US Naval Institute Press, ISBN 0-87021-101-3 , p. 96
- ^ Reports on the nuclear test "Able", Bureau of Ships Group, Technical Inspection Report, AD366709, p. 18
- ^ A radar history of World War II: technical and military imperatives, Louis Brown, 1999, Institute of Physics Publication, ISBN 0-7503-0659-9 , p. 413
- Jump up ↑ Japanese Radar and Related Weapons of World War II, Nakagawa Yasuzo, Aegean Park Press, 1998, ISBN 0-89412-271-1
literature
Sources for the Nagato class:
- Gakkan (publ.), Nagato Class, Pacific War Series, No. 15, ISBN 4-05-601684-4 , 1998
- Gakken (publ.), Battleships of Japan (Tokyo 2004)
- Kaijinsha (publ.), The Imperial Japanese Navy (in 14 volumes), Volume 1 (Battleships 1) (Tokyo 1989/1994), ISBN 4-7698-0451-2
- Fukui Shizuo , Japanese Naval Vessels Illustrated, 1869–1945 (in three volumes), Volume 1, Battleships and Battlecruisers (Tokyo 1974)
- Ishiwata Kohji , Japanese Battleships, Ships of the World Band 391 (Tokyo 1988)
- Miroslaw Skwiot , Nagato Mutsu, Monograph Morskie No. 5, AJ-Press, 1996, ISBN 83-86208-43-0
- Reports of the US Naval Technical Mission to Japan, Series A, E, O, S and X.
Sources on the political situation and planning of the Japanese Navy:
- Kaigun: Strategy, Tactics, and Technology in the Imperial Japanese Navy, 1887-1941 David C. Evans, 2003, US Naval Institute Press, ISBN 0-87021-192-7
