AM class (submarine)
 I-14, right, next to two Sen Toku-class boats, 1945
|
||||||||||||||
|
||||||||||||||
|
||||||||||||||
|
||||||||||||||
|
||||||||||||||
|
||||||||||||||
The AM-class was a class of submarines of the Imperial Japanese Navy that was built towards the end of World War II. AM class refers to a modified version of the A2 submarine series . In addition to the Sen Toku class submarines , the AM class was the only submarine class of its time that was designed for the use of several combat aircraft.
development
The boat class represented a new submarine doctrine, in which submarines were no longer added together with rapid surface combat groups as their support. The need for high speeds was eliminated, but range, sea endurance and transport capacity became important.
construction
The pressure hull in the fuselage was divided into eight sections:
- Torpedo room
- front crew compartment and below the accumulators
- Control room with control controls, radio rooms and below the pump room
- Auxiliary engine room
- Main engine room
- E-machine room
- aft crew room with rudder mechanics
The superstructures consisted of:
- the cylindrical aircraft hangar, above the control room on the longitudinal axis of the boats
- the control center, also in a cylindrical container on the port side
- the tower , above the control center on the port side
The following attachments were available on deck:
- an airplane catapult in front of the tower
- a fold-out crane in the hull in front of the tower on port side
- a fold-out radio mast embedded in the hull on the stern to starboard
- a storage area embedded in the hull for a dinghy on the stern to port
- two triple anti-aircraft guns on the roof of the hangar, one each aft and one in front of the tower
- a simple mount with an anti-aircraft gun in the rear of the tower
technology
Hull and driving characteristics
The 113.7 meter long steel hull consisted of 7 mm thick steel plates. It was provided with a sound-absorbing coating on the outside, which consisted of a rubber compound. During the application process, gas bubbles were generated in the rubber mixture by sulfur chlorides, which, after the material had solidified, were able to partially absorb sound waves. Not only has the effectiveness of active sound location systems such as the ASDIC been reduced, but the noise emitted by one's own boat has also been reduced and its location has been made more difficult by passive systems.
Inside the hull was the 92.96 meter long steel pressure hull, which housed the crew, armament and propulsion systems. The maximum wall thickness was 2.7 cm. The construction was designed for a diving depth of around 100 meters.
The dive time was around 50 seconds for the relatively large boats. The arrangement of the turret on the port side meant that the boats drifted continuously to the left, even when the oars were pointed on a straight course. In order to go straight ahead, the rudders had to be aligned on a course of 7 ° to starboard. The turning circle of the boats also differed accordingly when diving - depending on whether you should drive to the left or right. With a steering course to starboard of 20 ° and a speed of five knots it was 585 meters - but with port 20 ° it was only 485 meters. When surfaced, the turning circle in both directions at 12 knots and a rudder angle of 15 ° was 777 meters.
drive
The main propulsion of the boats were two Kampon Type 22 Model 10 diesel engines, each with 2,600 SHP. These comparatively weak four-stroke engines were not used in submarines until 1943, when it became clear that the ability to drive at high speed on the surface was no longer beneficial, but the range played a greater role. The two auxiliary diesel engines were identical to those mounted in the Sen-Toku class boats. The four-stroke engines with six cylinders each had an output of 450 kW .
The fuel supply for the diesel engines was around 1,268 tons and was stored below the engine room within the pressure hull.
The electric motors were two model 8 motors with 1,100 kW each. They obtained power from 240 type 1 Mod. 13 battery cells installed in Department 2.
Airplanes and hangar
The boats were equipped with a cylindrical hangar, which was placed above the main pressure hull along the keel line. The diameter of the hangar was 3.5 meters with a length of 20 meters. Two Aichi M6A aircraft could be stored in the hangar . As with the aircraft on board the Sen Toku class, these machines were also partially dismantled so that they could fit into the narrow hangar: the wings were folded down directly at the approach to the fuselage, as were the elevators , which reduced the width of the aircraft to a minimum .
The height of the aircraft was reduced by folding the tip of the rudder to the side and storing the aircraft in the hangar without floats. The floats were stored separately in two containers in the submarine hull.
If the aircraft were to be started, the mechanics climbed out of the pressure hull into the aircraft hangar and removed the hose connections for refueling the aircraft and the cables for powering their batteries.
The boat appeared, the watertight hangar door was opened and the rails on which the sledges with the two machines rested were connected to the rails that led to the catapult on deck. The front Aichi M6A was pushed outside, the wings, rudder and elevator were brought into the flight position and locked there, and the floats were pulled out of the storage containers and mounted on the fuselage. The crew climbed into the plane, then the plane was brought into position on the compressed air catapult and started.
After an aircraft landed on the water, the crane on the bow of the submarine on the port side was lifted out of its crate and erected. The M6A was lifted on board, dismantled and stowed.
Armament
The main armament of the boats were six bow torpedo tubes for torpedoes with a diameter of 533 mm. With six Type 95 torpedoes in the tubes and ten reserve torpedoes in the torpedo room, 16 weapons could be carried. Although all torpedo tubes had the connections to preheat accumulator cells such as those used in electric torpedoes, Japanese officers testified when questioned after the war that no Type 92 torpedoes had been used in the boats.
For air defense, two triple automatic cannons 25 mm L / 60 Type 96 Model 4 were mounted on the roof of the aircraft hangar. A single 25 mm L / 60 automatic cannon Type 96 Model 4 was positioned in the rear of the tower. In addition to the automatic cannons, pressure-resistant containers were installed in which the 15 round magazines with the ammunition were stored. A total of 11,200 rounds of 25 mm ammunition were carried.
The two Aichi M6A aircraft on board were able to carry additional weapons. Each could carry 800 kg of bombs or a Type 91 torpedo .
AM class boats
Originally the construction of four boats of the type had started, but only two were finished, the construction of the other two was canceled.
I-13
I-13 was laid on February 4, 1943 in Kobe . It was launched on November 30, 1943 and entered service on December 16, 1944. While she was en route from Japan to Truk , she was lost and was probably tracked down and sunk by an American anti-submarine group around July 16, 1945.
I-14
I-14 was laid on May 18, 1943 in Kobe. It was launched on March 14, 1944 and entered service on March 14, 1945. After the war it was taken over by the Americans and moved to Hawaii when it became clear that Soviet experts, according to the Allied agreements, wanted to examine the boats. When the Soviet Union again demanded the inspection of the boats, American warships finally sank I-14 together with the Sen Toku class boats near the Hawaiian archipelago in 1946 in order not to have to share the findings. In 2009 an underwater expedition found the wreck.
Evidence and references
Remarks
- ↑ According to USNTMJ S-01-7, p. 44: 335,000 US gallons × 3.785 = 1,268,112.95 liters
Individual evidence
- ↑ USNTMJ S-01-7 p. 48.
- ↑ USNTMJ E-10 pp. 55 and 56
- ↑ a b USNTMJ S-01-7 p. 47.
- ↑ USNTMJ S-01-7 p. 60.
- ↑ USNTMJ S-01-7 p. 59.
- ^ Carl Boyd, Akihiko Yoshida: The Japanese Submarine Force and World War II. P. 41.
- ^ Carl Boyd, Akihiko Yoshida: The Japanese Submarine Force and World War II. P. 27.
- ^ 2 Sunken Japanese Subs Are Found Off Hawaii Henry Fountain, New York Times, November 12, 2009
literature
- Carl Boyd, Akihiko Yoshida: The Japanese Submarine Force and World War II. US Naval Institute Press, 2002, ISBN 978-1-55750-015-1 .