Taihō (ship, 1944)
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The Taihō ( Japanese 大 鳳 ) was an aircraft carrier that was put into service by the Imperial Japanese Navy towards the end of the Pacific War in 1944. She was a single ship and did not belong to any ship class. It was sunk during its first use in June 1944.
history
construction
The Taihō was planned with the intention of using its aircraft closer to enemy naval units than was possible with previous Japanese aircraft carrier designs. The advantage was the shorter arrival and departure times of the company's own aircraft and thus a higher degree of efficiency . The disadvantage of such a design was the increased likelihood of enemy attacks, so that both the installation of heavy armor and that of heavy anti-aircraft weapons in the new type of ship were imperative.
The construction of the ship was planned for the first time in the five-year plan of the Imperial Navy of 1939.
The underwater ship of the Taihō was based on that of the successful Shōkaku class , with a bulbous bow behind the forward plumb line , four propellers and a main and an emergency rudder. The dimensions of the Taihō were then similar to those of the Shōkaku class in terms of length . At 260.6 meters, it was only around 4 meters longer than the Shōkaku- class ships, but the ship's width increased by around 13 percent due to the wide flight deck, so that the Taihō made a much more compact impression than its predecessor.
The longitudinal axis of the flight deck was not directly above the keel line of the hull, but was shifted two meters to port to compensate for the weight of the armored bridge structure on the starboard side. The bridge tower had been significantly enlarged and now for the first time included a chimney to discharge the exhaust gases from the boiler systems. The previous practice of discharging the exhaust gases through the outer wall of one of the hangars and then pushing them down to the surface of the water has been abandoned here. The heavy armor of the ship resulted in a greater draft and forced the developers to make appropriate compromises in the planning, so that a deck was omitted and a chimney that protruded from one of the ship's sides just above the waterline was out of the question because of the low freeboard . In addition, the bow was led to the lower edge of the flight deck, which made the Taihō one of the first Japanese aircraft carriers with a closed bow.
Protection system
As the first Japanese carrier, the Taihō had an armored flight deck to protect against aerial bombs and grenades that hit the deck. The deck received a layer of 75 mm NVNC armor steel and one made of 20 mm DS steel . The floor of the upper hangar below consisted of a 10 mm thick layer of DS steel plates, which were installed here as splinter protection due to their high yield strength . The floor of the lower hangar deck was the actual armored deck that protected the boiler and engine rooms. It consisted of 32mm CNC armor steel, a replacement for NVNC armor steel used on thinner armor plates, combined with 16mm DS steel.
The number of aircraft elevators in the flight deck has been reduced to two compared to the previous classes. They received protection from two layers, each with 25 mm DS steel plates. Despite this enormous weight on the elevator plates, each elevator could lift 7.5 tons of load and cover the distance from the lower hangar deck to the flight deck in 15 seconds.
Protection from flat track fire was ensured by belt armor made of 55 mm DS steel above the engine rooms. This armor protection grew over the magazines to 140 to 165 mm thick layers of CNC steel plates.
The structural protection of the underwater hull against torpedo hits or sea mines should absorb the effects of a 300 kg explosion of TNT without causing damage to the ship's important systems. It consisted of a torpedo bulkhead about three meters behind the ship's side, which was closed on the outside by two layers of watertight compartments, one of which was filled with air and the other with heavy oil. Inwardly, the bulkhead was followed by two more layers, again one empty and one filled with heavy oil.
The bridge superstructures were protected with a splinterguard made of DS steel, the navigating bridge was additionally armored with 40 mm CNC steel in order to withstand fire with shells of medium caliber.
Flight facilities
The ship received a flight deck, which with a length of 257.5 meters extended almost the entire length of the ship and which was 30 meters wide at its widest point. There were 14 safety ropes distributed over the deck, plus three net arresting systems to stop machines that were not held by the safety ropes.
The plan to install two aircraft catapults at the top of the flight deck was abandoned, and the ship was also not given a hinged windbreak, as installing it in the armored flight deck would have been too expensive.
The ship had two elevators to move planes out and into the two hangar decks. The elevator in the front half of the ship had dimensions of 14 m × 13.6 m, the one in the aft was 14 × 14 m.
The planning provided for the equipment to be equipped with 63 modern machines, and 15 partially dismantled reserve machines should be able to be carried. However, the requested aircraft were not available at the time of the first mission, and so in June 1944 the Taihō carried 27 Mitsubishi A6M5 , 30 Yokosuka D4Y / Aichi D3A and 18 Nakajima-B6N2 torpedo bombers .
Armament
The main armament of the Taihō was the new 10 cm type 98n cannons with a caliber length of 65. They were set up in six twin mounts, three each on port and starboard. The weapon fired grenades at up to 21 rounds per minute with a range of almost 20,000 meters and was considered one of the most advanced weapons in the Japanese arsenal.
The usual equipment of Japanese warships with the 25 mm Type-96 cannon was chosen as armament for close range . These automatic cannons were installed in 17 triplet mounts. Before it was deployed, the ship received another 20 Type-96s in single mounts.
The fire control for the heavy anti-aircraft guns was based on two Type 94 control units. The 17 triplet mounts of the light anti-aircraft armament were steered by eight fire control devices, but the retrofitted single mounts were not integrated into this control system.
The ship's two Type 21 radar systems were not suitable for fire control due to their poor accuracy and were therefore not connected to the air defense control systems.
drive
The Taihō's drive system consisted of eight Kampon steam boilers that burned heavy oil to generate hot steam to drive the four steam turbines. The machine output was 160,000 SHP (117,680 kW ); so she reached 33.3 knots .
At 18 knots, the fuel carried was enough for around 8,000 nautical miles to travel.
Planned improved Taihō class
In the modified 5th shipbuilding program ( Kai-Maru-Go ) of the Japanese Navy from September 1942, the construction of five naval carriers based on the Taihō model was planned, which should, however, receive some improvements. Priority was given to the construction of 15 medium-sized girders of the Unryū class , which could be completed more quickly and with less effort. In the further course of the war, a lack of resources meant that only five Unryū class carriers were keeled (two of which were completed) and the improved Taihō class was dispensed with entirely.
Calls
The Taihō served as the flagship of Vice Admiral Ozawa Jisaburō and went to the Philippine Sea near the Mariana Islands together with the porters Shōkaku and Zuikaku immediately after a few test drives .
Philippine Sea
In the Battle of the Philippine Sea , Ozawa's fleet came together with Task Force 58 , a fleet of aircraft carriers in the United States Navy under the command of Admiral Marc Andrew Mitscher . The naval battle had developed in an attempt by the Imperial Navy to prevent the invasion of Saipan by American troops.
The Japanese carrier ran on June 19, 1944 27 knots, turned into the wind and started around 8:25 their fill of 128 combat aircraft first wave of attacks, including 42 machines from the Taihō .
The US submarine Albacore came into the optimal firing position to attack the Taihō , and released six torpedoes at 8:32 a.m. from about 8,000 meters away . As the Japanese aircraft carrier ran in the direction of the submarine, the distance the weapons traveled was shortened to about 2,000 meters.
A pilot of the Taihō , Sergeant Sakio Komatsu, who had recently taken off from the flight deck with his Yokosuka D4Y , discovered one of the torpedoes and threw himself on the weapon with his machine, the following explosion destroyed the aircraft and possibly the torpedo, but still hit one of the torpedoes from the compartment after about two minutes of running the Taihō at the height of the front elevator at frame 54 on the starboard side.
The explosion was absorbed by the structural protection system of the fuselage so that it did not penetrate into the tanks with the highly flammable aviation fuel . The outer side of the hull and the torpedo bulkhead behind it had been perforated, however, so that seawater mixed with heavy fuel oil from one of the bunkers penetrated the ship and also into a room with a jet fuel tank. The damage was classified as not critical. The water ingress was not progressive and was limited to a small area, the draft of the Taihō only increased by 1.5 meters at the forecastle, but the speed and position in the fleet could be maintained.
Further damage was caused by the shock of the torpedo explosion: the front elevator had sunk around two meters below the flight deck and could no longer be moved. In addition, a tank with aviation fuel had leaked from the shock wave of the torpedo explosion and one of the armored transverse bulkheads in the area had warped and was also no longer tight. The gasoline from the damaged tank was forced through the leak in the bulkhead into the lower part of the elevator shaft by the penetrating mixture of oil and water.
Other reports describe damage to the aviation fuel tanks that had no connection to the open sea, so that only fuel flowed into the space around the tanks, while the vapors were distributed via vents and a leaky bulkhead in the ship.
Downfall
After the ship's security had covered the front elevator shaft with planks, flight operations were possible again on the flight deck. Only the lower end of the front elevator shaft remained problematic, in which the water rose to the level of the outer waterline while the lighter jet fuel began to settle above the water level in the shaft. The gasoline outgassed and combined with the ambient air to form a highly explosive mixture. An attempt to pump the gasoline out of the shaft failed, and some of the gasoline that you actually wanted to pump out may leak in the ship. The crew suffered increasingly from the inhaled vapors, so that dizziness and nausea further impaired the performance of the seafarers in the hangar decks.
The last 16 aircraft had already started at around 9:00 a.m. and the crew began trying to ventilate the two hangar decks to prevent an explosion. Here, the construction of the ship with the armored hangar walls, in which there were no larger openings, proved to be an obstacle. Therefore, the opening of all hatches was ordered, because it was hoped that the natural air movements outside and the airstream would reduce the gas concentration to a safe level. As a result, the gasoline fumes now spread to areas of the ship that were not previously affected. Another order was given instructing the activation of all ventilation systems in the ship. The motors of these fans, however, created a multitude of potential ignition sources, so that at 3:32 p.m. a devastating gas explosion occurred.
The explosion created a pressure wave within the hull that ripped open and bulged the armored flight deck in some places, but its destructive force was mainly diverted into the interior of the ship, where it was directed against the bulkheads inside and against the sides of the hull and both Straightened hangar decks.
The fires that followed the explosion could no longer be controlled, and further damage to the ship was caused by secondary explosions of ammunition, so that the Taihō slowly began to lay on the port side as a result of new water ingress.
Surviving crew members were mostly surprised by the explosion at their posts above the hangar deck, while only a few soldiers survived from inside the hull. These came from boiler room number 2 and from the orlop deck and had left the ship in their area through the torn side wall.
The losses among the pilots of the Taihō , who took off to attack the American carrier fleet, were extremely high due to the loss of 80% of the aircraft in the fleet. The surviving machines probably landed on the Zuikaku , but a few could have landed on the Taihō just before the ship exploded. The Shōkaku was already a burning wreck at this point, so that their planes also had to land on the Zuikaku .
Around 4:30 p.m., the burning Taihō went down over the bow with 660 men after the surviving 1,090 crew members, including Vice Admiral Ozawa, were picked up by escort ships and taken to the heavy cruiser Haguro and the Zuikaku .
examination
A comprehensive investigation into the loss of the Taihō was initiated, but the result report of the commission was lost in the chaos of war. A combination of design flaws and human error led to the loss of the ship, according to surveys from 1946.
- The position of the aviation fuel tanks directly below the front elevator shaft ensured that escaping gasoline and its vapors could only rise up through one watertight bulkhead in the shaft after the crack.
- Failure of the ship's security, which did not succeed in sealing the shaft with a foam blanket and pumping out the mixture of water, heavy oil and gasoline.
- Failure of the ship's command to order the opening of all hatches and thus to distribute the explosive fumes throughout the ship and thereby expose them to ever more potential sources of ignition.
wreck
The wreck of the Taihō has not yet been found. Their last known position was 12 ° 5 ' N , 138 ° 12' O .
See also
Remarks
- ↑ The information on the thickness of the belt armor varies, depending on the source, between 140 and 165 mm. So 140 mm in USNTMJ S-01-9 and: WARSHIPS OF THE IMPERIAL JAPANESE NAVY - Shokaku class, Soryu, Hiryu, Unryu class, Taiho.
- ↑ The type of aircraft that Komatsu flew is given in western sources sometimes as Jill , sometimes as Judy or Zeke .
- ↑ Other sources claim the elevator stopped moving up while an A6M fighter was still on it. In the translation of Kojinsha number 6 at combinedfleet.com
- ↑ other sources give 14:32 as the time of the explosion. For example, Mark Stille and Tony Bryan in Imperial Japanese Navy Aircraft Carriers 1921–45. on p. 47.
Evidence and references
literature
- Collective of authors of the Maru magazine: WARSHIPS OF THE IMPERIAL JAPANESE NAVY - Shokaku class, Soryu, Hiryu, Unryu class, Taiho. (Japanese: 空 母 翔 鶴 ・ 瑞鶴 ・ 蒼龍 ・ 飛龍 ・ 雲龍 型 ・ 大 鳳) Kōjinsha, Tokyo 1996, ISBN 978-4-7698-0776-6 .
- United States Naval Technical Mission to Japan, report S-06-2: Reports of Damage to Japanese Warships-Article 2, YAMATO (BB), MUSASHI (BB), TAIHO (CV), SHINANO (CV).
- United States Naval Technical Mission to Japan, report S-01-9: Characteristics of Japanese Naval Vessels-Article 9, Underwater Protection.
- United States Naval Technical Mission to Japan, report O-47 (N) -1: Japanese Naval Guns and Mounts-Article 1, Mounts Under 18
- United States Naval Technical Mission to Japan, report A-11: Aircraft Arrangements and Handling Facilities on Japanese Naval Vessels.
- William T. Y'Blood: Red Sun Setting. The Battle of the Philippine Sea. US Naval Institute Press, 2003, ISBN 978-1-59114-994-1 .
- Mark Stille, Tony Bryan: Imperial Japanese Navy Aircraft Carriers 1921–45. Osprey Publishing, 2005, ISBN 978-1-84176-853-3 .
- Mark R. Peattie: Sunburst. The Rise of Japanese Naval Air Power, 1909-1941. US Naval Institute Press, 2007, ISBN 978-1-59114-664-3 .
- David C. Evans: Kaigun. Strategy, Tactics, and Technology in the Imperial Japanese Navy, 1887-1941. US Naval Institute Press, 2003, ISBN 0-87021-192-7 .
Web links
- Use history of Taiho of A. Tully (Engl.)
- PDF - English translation of the Japanese template: Kōjinsha number 6 WARSHIPS OF THE IMPERIAL JAPANESE NAVY by Sander Kingsepp, Hiroyuki Yamanouchi, Yutaka Iwasaki and Katsuhiro Uchida Quinn Bracken on combinedfleet.com
Footnotes
- ↑ a b c USNTMJ S-01-3 p. 45
- ↑ a b c d so in the translation of Kojinsha number 6 at combinedfleet.com, viewed on April 14, 2011
- ↑ USNTMJ S-06-2, p. 32
- ↑ USNTMJ S-06-2, p. 23
- ↑ Kaigun. Strategy, Tactics, and Technology in the Imperial Japanese Navy, 1887-1941. P. 358.
- ↑ USNTMJ A-11, p. 14
- ↑ USNTMJ A-11, p. 8
- ↑ USNTMJ O-47-1, pp. 48 and following
- ↑ USNTMJ O-47-1, p. 2
- ↑ Translation of WARSHIPS OF THE IMPERIAL JAPANESE NAVY on combinedfleet.com, page 54 (PDF; 235 kB)
- ^ William T. Y'Blood: Red Sun Setting. The Battle of the Philippine Sea. P. 115.
- ↑ a b c d e USNTMJ S-06-2, pp. 23, 24 and 25
- ^ Mark R. Peattie: Sunburst. The Rise of Japanese Naval Air Power, 1909-1941. P. 158.