Type 92 torpedo
| Type 92 torpedo | |
|---|---|
| General Information | |
| Designation: | 九二 式 電池 魚雷 |
| Country of origin: | Japan |
| Manufacturer: | Imperial Japanese Navy |
| Working time: | 1942 to 9/1945 |
| Technical specifications | |
| Length: | 7.15 meters |
| Diameter: | 533 millimeters |
| Combat weight: | 1720 kilograms |
| Drive: | Electric motor |
| Speed: | 28 knots |
| Range: | 7000 meters |
| Furnishing | |
| Warhead: | 300 kilograms highly explosive |
| Target location: | no |
| Lists on the subject | |
The Type 92 torpedo ( Japanese 九二 式 電池 魚雷 , Kyūni-shiki denchi gyorai , German "Type 92 battery torpedo ") was a torpedo of the Imperial Japanese Navy , which was used by submarines . The designation Type 92 indicates the year of the first development, the year Kōki 2592 or 1932 according to the Gregorian calendar.
Development and evaluation
development
After the Imperial Navy learned of the introduction of an electrically powered torpedo to the German Reichsmarine in 1921 , it began its own program to develop such a weapon. A first prototype was produced in 1925 and after a lengthy optimization phase, the Type 92 was developed in 1932. In 1934, preparations for series production were completed. The actual series production did not begin until the outbreak of the Pacific War in 1941/1942. The variant produced was given the name Type 92 Modification 1. About 650 pieces were produced in the naval workshops in Yokosuka , Kure and Maizuru .
rating
The advantages of the Type 92 torpedo lay on the one hand in the fact that it did not expel any air bubbles when it was running and was therefore hardly detectable. On the other hand, the maintenance was not time-consuming or dangerous, since refueling with oxygen, as with the torpedo Type 95 , which was used around the same time , was unnecessary.
The main disadvantages of the Type 92 torpedo were its short range of only 7000 meters and its low top speed compared to the Type 95 torpedo. A weak point in the design was the connection between the battery compartment and the stern section, where water repeatedly came through leaks penetrated. This problem could not be resolved with the later modification of the weapon to the Kaiten .
construction
The Type 92 was outwardly similar to the Torpedo Type 95 , the dimensions and steering gear of which had been adopted, but was supplied with energy by two sets of 54 lead-acid battery cells each. The battery contained 21 plates per cell, each composed of ten positive and eleven negative electrodes. The dimensions of each cell were 24 cm in length, 13 cm in height and 8 cm in width.
The cells were stored on a total of six heating elements, which could be powered by the submarine's power supply before the weapon was used in order to bring the batteries in the torpedo to an optimal operating temperature. The elements had an output of 250 watts and were operated with 220 volts.
The actual drive was a 200 volt , 450 ampere direct current machine with six poles and intermediate poles. It developed around 95 hp (69.87 kW ) at 1250 revolutions per minute. The energy was transferred to two propellers at the stern, which could accelerate the torpedo to 28 knots.
commitment
The crew in the torpedo room of the submarine use a key to unlock the connection between the batteries and the engine through an opening on the torpedo body. She then loaded the Type-92 into one of the torpedo tubes . A compressed air line in the torpedo tube was used to force air through the battery compartment through a valve on Type 92 in order to discharge gases that could arise when the accumulators were outgassed via a check valve, so that the risk of a possible gas explosion was reduced.
The control commands for depth and course of the torpedo were transmitted to the Type 98 gyro instrument and the depth control of the weapon via connections in the torpedo tube . After the torpedo was ejected, compressed air was used to transmit the control commands from the gyroscopic instrument and depth gauge to the rudders at the rear of the weapon. The control depth of the weapon, which could be adjusted when firing, had to be between two and twelve meters, the heading at + or - 180 °.
The engine started slowly with the fire command and began to increase its speed. When each of a total of five operating points was reached, a series resistor was switched off in the power supply, so that after 130 revolutions the motor was connected directly to the battery.
When it hit an obstacle, the Type 90 impact fuse ignited the 300 kg explosive charge in the front part of the torpedo body.
Tests with acoustic target search
A torpedo with acoustic target search, based on the Type 92, was tested by the Imperial Navy during the course of the war. The weapon had two hydrophones in its nose , one of which was mounted 30 ° to the left and the other 30 ° to the right of the weapon’s longitudinal axis. Two modes of operation were tested, but never produced in the form of an operational weapon:
- The weapon turned in the direction of the hydrophone that was receiving the louder noise until the noise level in the second hydrophone was higher. Then she followed that signal and so on. So the torpedo moved in ever smaller curve movements towards its target, the source of the noise.
- The signals were passed to an amplifier and the course to a noise source was to be determined based on the phase deviation between the hydrophones. This control method was more precise and because the weapon did not take turns, the range also increased. However, the technical implementation required far more precision and was more complex.
variants
- Type 92 Modification 2 - Based on six German G7e torpedoes that had been delivered as part of the alliance in 1942, the Japanese Navy began to revise the Type 92, but did not finish this work until the end of the war.
- The Type 92 was used as the basis for the "Model X" of the Kaiten small-scale weaponry.
Remarks
- ↑ An examination of the accumulators used by American scientists in 1946 showed that the batteries were comparatively poorly designed. They showed severe performance deficits due to the insufficient amount of electrolyte and were very sensitive due to the tight electrode gaps and breakable spacers. The Japanese put the power at 150 amperes, while the Americans calculated it to be 90. USNTMJ S-92, page 40 and following.
- ↑ Original description of the machine in English from USNTMJ O-O1-1, p. 78: six-pole, compound interpole machine connected in long shunt operating at 200 volts, 450 amps
- ↑ the same model was used in the Type 95 and Type 93 torpedoes
Individual evidence
- ↑ USNTMJ O-O1-1, page 421
- ↑ USNTMJ O-O1-1, page 417
- ↑ USNTMJ O-O1-1, p. 290
- ↑ navweaps.com sighted March 3, 2011
literature
- Carl Boyd, Akihiko Yoshida: The Japanese submarine force and World War II. Publisher US Naval Institute Press, 2002, ISBN 1557500150
- REPORTS OF THE US NAVAL TECHNICAL MISSION TO JAPAN 1945-1946, SERIES O: ORDNANCE TARGETS, JM-200-D, O-O1-1, Japanese Torpedoes and Tubes-Article 1, Ship and Kaiten Torpedoes