Japanese torpedoes:
17.7" (45 cm) Type 91 (1931) Mod 1
Torpedo Type: Aircraft
Date Of Design: 1931
Date In Service: 1933
Weight: 1,728 lbs. (784 kg)
Overall: Length 17 ft 3.7 in (5.275 m)
Explosive Charge: 331 lbs. (150 kg) Type 97
Range / Speed: 2,200 yards (2,000 m) / 41-43 knots
Power: Kerosene-air wet-heater
Notes: This was a pre-war torpedo although still in service ten years later. "Nell" torpedo bombers carried this weapon against the HMS Prince of Wales and HMS Repulse on 10 December 1941.
17.7" (45 cm) Type 91 (1931) Mod 2
Torpedo Type: Aircraft
Date Of Design: 1940
Date In Service: 1941
Weight: 1,841 lbs. (935 kg)
Overall Length: 18 ft 0 in (5.486 m)
Explosive Charge: 452 lbs. (205 kg) Type 97
Range / Speed: 2,200 yards (2,000 m) / 41-43 knots
Power: Kerosene-air wet-heater
Notes: Compared to Mod 1, Mod 2 had a heavier explosive charge, a thinner air vessel and anti-roll stabilizers. It was first delivered in April 1941 and was first carried into action by "Betty" bombers against the Prince of Wales and Repulse. A heavily modified version able to be used in shallow waters was used by the "Kate" bombers at Pearl Harbor.
17.7" (45 cm) Type 91 (1931) Mod 3
Torpedo Type: On Aircraft
Date Of Design: 1941
Date In Service: 1942
Weight: 1,872 lbs. (849 kg)
Overall Length: 18 ft 0 in (5.486 m)
Explosive Charge: 529 lbs. (240 kg) Type 97
Range / Speed: 2,200 yards (2,000 m) / 41-43 knots
Power: Kerosene-air wet-heater
Notes: Compared to Mod 2, Mod 3 had a heavier explosive charge, the air vessel was thickened for a heavier charge. Bronze parts were substituted for steel where possible and eight tail fins were experimented with in some units.
17.7" (45 cm) Type 91 (1931) Mod 3 Improved, Mod 3 Strong and Mod 4
Torpedo Type: Aircraft
Date Of Design: Improved: 1942; Strong: 1943; Mod 4: 1943
Date In Service: Improved: 1943; Strong: 1944; Mod 4: 1944
Weight: Mod 3 Improved and Strong: 1,872 lbs. (849 kg); Mod 4: 2,030 lbs. (921 kg)
Overall Length: 17 ft 3.7 in (5.275 m)
Explosive Charge: Mod 3 Improved and Strong: 529 lbs. (240 kg) Type 97; Mod 4: 679 lbs. (308 kg) Type 97
Range / Speed: Improved: 2,200 yards (2,000 m) / 41-43 knots; Strong and Mod 4: 1,640 yards (1,500 m) / 41-43 knots
Power: Kerosene-air wet-heater
Notes: Compared to Mod 3, Mod 3 Improved had a heavier explosive charge, the top side of the afterbody and engine room strengthened with longitudinal T bars to permit 300 knot launching speed. This was followed in 1944 by the Mod 3 Strong which had I instead of T bars for strengthening the top side of the afterbody and also the underside of the warhead nose, the air vessel was thinned with reduced pressure and range. These modifications allowed a 350 knot launching speed. Mod 4 was the same torpedo with a heavier explosive charge. The Strong and Mod 4 are the torpedoes that the Ki-67 should have available.
21" (53.3 cm) Type 92 (1932) Mod 1 and Mod 2
Torpedo Type: Submarine
Date Of Design: 1932
Date In Service: 1934 (1942 quantity production)
Weight: 3,792 lbs. (1,720 kg)
Overall Length: 23 ft 5.5 in (7.150 m)
Explosive Charge: 661 lbs. (300 kg) Type 97
Range / Speed: 7,650 yards (7,000 m) / 28-30 knots
Power: Lead-acid electric batteries
Notes: The design of this torpedo was inspired by the German Navy's successful one of WWI. Work started in 1921 and in 1925 workable models were produced. Design work continued and the Type 92 Mod 1 was ready for production in 1934. As there was no need for this torpedo at that time, the design was set aside. In 1942 production started to supplement the Type 95 torpedoes. The Type 92 was slower than the Type 95 but had even less track and was easier to produce. The Type 92 Mod 2 was to have been based upon the German G7e and ten of these torpedoes were delivered to Japan in 1942. However, a lack of manpower killed this project.
24" (61 cm) Type 93 (1933) Model 1, Mod 1, Mod 2 and Mod 3
Torpedo Type: Surface Ship
Date Of Design: 1933
Date In Service: 1935
Weight: 5,952 lbs. (2,700 kg)
Overall Length: 29 ft 6.3 in (9.000 m)
Explosive Charge: 1,080 lbs. (490 kg) Type 97
Range / Speed: 21,900 yards (20,000 m) / 48-50 knots; 35,000 yards (32,000 m) / 40-42 knots; 43,700 yards (40,000 m) / 36-38 knots
Power: Kerosene-oxygen wet-heater
Notes: Model 1 was the prototype version of the famous "Long Lance" torpedoes. The first production version was Model 1 Mod 1. Mod 2 dated from 1936 and differed in many areas. The oxygen vessel was made of a deep pressing with one integral end instead of a hollow forging. This construction was followed in all subsequent versions. The bracing ribs of the rear buoyancy chamber were strengthened and cooling water to the slide valves was increased together with modifications to the buffer chamber, lubrication of the cross-head and group valve gearing. Mod 3 was designed in 1944, but was never in service.
24" (61 cm) Type 93 (1933) Model 3
Torpedo Type: Surface Ship
Date Of Design: 1943
Date In Service: 1944
Weight: 6,173 lbs. (2,800 kg)
Overall Length: 29 ft 6.3 in (9.000 m)
Explosive Charge: 1,720 lbs. (780 kg) Type 97
Range / Speed: 16,400 yards (15,000 m) / 48-50 knots; 27,300 yards (25,000 m) / 40-42 knots; 32,800 yards (30,000 m) / 36-38 knots
Power: Kerosene-oxygen wet-heater
Notes: A slightly improved version, trading a shorter range for a much larger explosive charge. The first air vessel was replaced by carbon tetrachloride to prevent an explosion on ignition.
21" (53.3 cm) Type 95 (1935) Model 1
Torpedo Type: Submarine
Date Of Design: 1935
Date In Service: 1938
Weight: 3,671 lbs. (1,665 kg)
Overall Length: 23 ft 5.5 in (9.000 m)
Explosive Charge: 893 lbs. (405 kg) Type 97
Range / Speed: 9,850 yards (9,000 m) / 49-51 knots; 13,100 yards: (12,000 m) / 45-47 knots
Power: Kerosene-oxygen wet-heater
Notes: A smaller version of the Type 93 developed for submarines.
21" (53.3 cm) Type 95 (1935) Model 2
Torpedo Type: Submarine
Date Of Design: 1943
Date In Service: 1944
Weight: 3,814 lbs. (1,730 kg)
Overall Length: 23 ft 5.5 in (9.000 m)
Explosive Charge: 1,213 lbs. (550 kg) Type 97
Range / Speed: 6,000 yards (5,500 m) / 49-51 knots; 8,200 yards (7,500 m) / 45-47 knots
Power: Kerosene-oxygen wet-heater
Notes: A slightly improved version, trading a shorter range for a much larger explosive charge.
21" (53.3 cm) Type 96 (1936 but actually 1941)
Torpedo Type: Submarine
Date Of Design: 1941
Date In Service: 1942
Weight: 3,814 lbs. (1,730 kg)
Overall Length: 23 ft 5.5 in (9.000 m)
Explosive Charge: 1,213 lbs. (550 kg) Type 97
Range / Speed: 4,900 yards (4,500 m) / 48-50 knots
Power: Kerosene-oxygen wet-heater
Notes: This was a modified Type 95 Mod 1 torpedo developed because of troubles with the "first air vessel" in the former. Type 96 used 36% oxygen rather than pure oxygen to reduce starting problems. This also allowed a thin coating of lubricating oil to be used on valves where as with pure oxygen they had to be completely oil free which caused corrosion and irregular functioning. The title of "Type 96" seems to have been given to fill a gap in the series.
17.7" (45 cm) Type 97 (1937)
Torpedo Type: Midget Submarine
Date Of Design: 1937
Date In Service: 1939
Weight: 2,161 lbs. (980 kg)
Overall Length: 18 ft 4.5 in (5.600 m)
Explosive Charge: 772 lbs. (350 kg) Type 97
Range / Speed: 6,000 yards (5,500 m) / 44-46 knots
Power: Kerosene-oxygen wet-heater
Notes: Designed for Midget Submarines and was essentially a smaller version of the Type 93 and Type 95 torpedoes. Only about 100 were made as similar problems with the first air vessel were found. Used operationally only during the Pearl Harbor attack.
17.7" (45 cm) Type 98 (1938 but actually 1941)
Torpedo Type: Midget Submarine
Date Of Design: 1941
Date In Service: 1942
Weight: 2,094 lbs. (950 kg)
Overall Length: 18 ft 4.5 in (5.600 m)
Explosive Charge: 772 lbs. (350 kg) Type 97
Range / Speed: 3,500 yards (3,200 m) / 40-42 knots
Power: Kerosene-oxygen wet-heater
Notes: Designed for Midget Submarines. Also known as the Type 97 Special. Worked on air enriched to 38% oxygen and bore the same relationship to the Type 97 as did the Type 96 did to the Type 95. Called the Type 98 to fill a gap in the series. About a total of 130 produced.
17.7" (45 cm) Type 4 (1944) Mark 2
Torpedo Type: Aircraft
Date Of Design: 1944
Date In Service: 1945
Weight: 2,169 lbs. (984 kg)
Overall Length: 17 ft 3.5 in (5.275 m)
Explosive Charge: 670 lbs. (313 kg) Type 97
Range / Speed: 1,640 yards (1,500 m) / 41-43 knots
Power: Kerosene-oxygen wet-heater
Notes: A further modification of the Type 91 Mod 3 Strong. This version was strengthened to permit a launch speed of 400 knots. The design was greatly simplified for easier production including the replacement of many steel parts by bronze. Also note that the designation system for modifications changed from "Mod" to "Mark" with this torpedo.
17.7" (45 cm) Type 4 (1944) Mark 4
Torpedo Type: Aircraft
Date Of Design: 1945
Date In Service: 1945
Weight: 2,434 lbs. (1,104 kg)
Overall Length: 18 ft 9 in (5.715 m)
Explosive Charge: 919 lbs. (417 kg) Type 97
Range / Speed: 1,640 yards (1,500 m) / 40-42 knots
Power: Kerosene-oxygen wet-heater
Notes: Similar to the previous Type 4 Mod 2 with a larger warhead.
