Type 96 and Type 97 150 mm infantry mortar
The Type 96 and Type 97 were Japanese 150 mm calibre mortars used during the Second World War. The Type 96 designation was given to this mortar as it was accepted in the year 2596 of the Japanese calendar, it had a caliber of 150.5 mm, 90 were produced. The Type 96 was used in Iwo Jima and China. In 1941 the weapon was developed into the more portable Type 97 150 mm Mortar, which has the recoil absorber removed. US War Department Special Series No 30 Japanese Mortars and Grenade Dischargers 1945 http://www3.plala.or.jp/takihome/mortar.htm#96
Type 97 Chi-Ni medium tank
The Experimental Medium Tank Chi-Ni was a prototype Japanese medium tank. Proposed as a low-cost alternative to the Type 97 Chi-Ha medium tank, it was passed over by its competitor. In 1935 news had reached Japan of the United Kingdom's development of an new tank, the A6 medium tank. A multi-turreted design that mounted a 47 mm tank gun and was capable of reaching speeds of 50 km/h. In comparison, Japan's tank force had not undergone any significant changes in tactics or organization in six years; the country's most fielded medium tank, the Type 89 I-Go, while popular with troops and tank crews had begun to show its age, attempts to update the design with the Type 89B I-Go Otsu were made in 1934, but no fundamentally new design was undertaken. In comparison, the A6 was seen as having superior offensive and defence capabilities over the Type 89 I-Go; the appearance of Britain's new tank design, along with reports from Manchuria of the Type 89's inability to keep up with other motorized vehicles–given its inadequate 25 km/h top speed–brought about plans for a replacement.
Tank designers recommended research on a new tank design, a medium tank capable of going 35 km/h and weighing 15 tons with offensive and defensive abilities greater than the Type 89 I-Go. The Chief-of-Staff Operations was not enthusiastic for the project as it was peace-time and the military had a limited budget; the army thus issued peace time requirements for a new tank design. Rather than focusing on performance improvements, the Chief-of-Staff Operations made a lighter weight the main requirement in order to lower production costs; the finalised requirements were for a lighter weight tank, capable of going 35 km/h, armed with a 57 mm main gun. The Engineering Department believed that it was regrettable that their efforts would be devoted to weight reduction, so instead, two concurrent projects were built; the first plan was for a lower-weight, low-cost medium tank, to be made by the Osaka Army Arsenal, which would become the Chi-Ni. The second plan was contracted to Mitsubishi Heavy Industries for a higher performance medium tank, which would become the Chi-Ha.
The initial design requirements for the two prototypes were: The Chi-Ni was envisioned as a smaller, lighter alternative to the Chi-Ha, a medium tank closer to the original Chief-of-Staff Operations preference for more "lightly armored infantry support vehicles". The hull was of a monocoque design and welding was used more extensively than previous tanks; this was unlike previous Japanese tanks. The Chi-Ni shared the same bell crank scissors suspension as the Chi-Ha that would continue to be used by Japanese tanks until the end of the Second World War; the hull was designed with a streamlined silhouette to protect from shell damage. The crew of the Chi-Ni, unlike the Chi-Ha was only made up of three men, with the tank commander acting as both a gunner and loader in the small, single-man turret; the turret did not have room for any coaxial machine gun. The driver was seated in the hull on the left hand side, with the third crew member, a machine gunner, was seated to right of the driver; the tank was planned to be armed with the Type 89 I-Gos Type 90 57 mm gun, but a new tank gun was being designed at the time to replace the lower velocity gun.
This improved tank gun was the Type 97 57 mm tank gun. A single, forward firing, 7.7×58mm Arisaka Type 97 machine gun was mounted in the hull. The diameter of the turret ring for both tanks was made as large as possible to allow for any future up-gunning of the tanks; the tank was powered by a Mitsubishi 135 hp diesel engine. There are documents stating that the Chi-Ni was tested with a 120 hp Mitsubishi A6120VDe air-cooled diesel engine from a Type 95 Ha-Go; the Chi-Ni was equipped with a'tadpole tail', a tail extension attached to the back of the tank to allow it to better cross trenches. Both prototypes were completed and tested in early 1937. During the time of the Chi-Ni and Chi-Ha trials, the China Incident occurred on 7 July 1937, sparking a war with China. With the out-break of hostilities the peacetime budgetary limitations were removed and the more capable and expensive Mitsubishi Chi-Ha model was accepted as the new Type 97 medium tank by the army; the Type 97 Chi-Ha would go on to be the most numerically important Japanese medium tank of the Second World War.
Only a single Chi-Ni prototype was built. Though the Chi-Ni was passed over in favour of the Chi-Ha, several individuals in the Japanese military, such as Japanese Army tank designer Lieutenant General Tomio Hara, believed that there was still potential in the design and the tank could be reused in the future as a light tank. Japanese tanks of World War II List of engines and weapons used on Japanese tanks during World War II List of Japanese armoured fighting vehicles of World War II Tomczyk, Andrzej. Japanese Armor Vol. 2. AJ Press. ISBN 978-8372371119. Zaloga, Steven J.. Japanese Tanks 1939–45. Osprey. ISBN 978-1-8460-3091-8. Taki's Imperial Japanese Army Page: "THE DEVELOPMENT OF IMPERIAL JAPANESE TANKS": Type 97 Medium Tank
Type 97 heavy tank machine gun
The Type 97 heavy tank machine gun was the standard machine gun used in tanks and armored vehicles of the Imperial Japanese Army during World War II, a heavy machine gun by infantry forces, This weapon was not related to the Type 97 aircraft machine gun used in several Japanese Navy aircraft including the A6M Zero. The Type 11 Light Machine Gun was modified by the Army Technical Bureau for use in tanks and other armored vehicles, was produced for this application under the designation "Type 91 Mobile Machine Gun". However, the basic design issues with the Type 11 remained, including its tendency to jam because of the slightest amount of grit or dirt, the low lethality and lack of stopping power of its 6.5x50mm Arisaka cartridges. During the early stages of the Second Sino-Japanese War, Japanese forces captured a number of Czech ZB vz/26 light machine guns from China’s National Revolutionary Army; this was used in a modified form for armored vehicles until 1940, when the Japanese Army switched to a rimless 7.7 mm cartridge.
The Type 97 was mechanically similar to the Czech ZB vz. 26, with a different stock and pistol grip. It had a straight, vertical, 20-round box magazine and used the same 7.7 mm cartridges used in the Type 99 rifle. The gun barrel could overheat, which meant the gunner had to fire in bursts, or the barrel would be shot out; when fitted in a tank, a fixed focus 1.5x telescopic sight with a 30° field of view was used. To prevent injury to the gunner, a rubber eye pad was attached to the rear of the sight; when used as an infantry weapon, a bipod was employed. Without the bipod, it weighed 11.25 kg. The Type 97 came into service in 1937, was used on all Japanese tanks and other armored vehicles until the end of the war; the Imperial Japanese Navy used the weapon in their combat vehicles such as the Type 92 Jyu-Sokosha Heavy Armored Car. It was much less common as a stand-alone infantry gun due to its weight; as a result of this weight problem, the similar looking but different internally Type 99 light machine gun was developed in the same caliber and deployed instead.
It was used by Communist forces during the Korean War. ZB vz. 26 Bren light machine gun Type 96 light machine gun Type 99 light machine gun Bishop, Chris. The Encyclopedia of Weapons of World War II. Barnes & Nobel. ISBN 0-7607-1022-8. CS1 maint: Extra text: authors list Mayer, S. L.. The Rise and Fall of Imperial Japan; the Military Press. ISBN 0-517-42313-8. Morse, D. R.. Japanese Small Arms of WW2. Firing Pin Enterprizes. ASIN: B000KFVGSU. Popenker, Maxim. Machine Gun: The Development of the Machine Gun from the Nineteenth Century to the Present Day. Crowood. ISBN 1-84797-030-3. Rottman, Gordon L.. Japanese Infantryman 1937-1945. Osprey Publishing. ISBN 1-84176-818-9. US Department of War. Handbook on Japanese Military Forces, TM-E 30-480. Louisiana State University Press. ISBN 0-8071-2013-8. US Technical Manual E 30-480 Dragonsoffire.com
The Kawanishi H6K was an Imperial Japanese Navy flying boat produced by the Kawanishi Aircraft Company and used during World War II for maritime patrol duties. The Allied reporting name for the type was Mavis; the aircraft was designed in response to a Navy requirement of 1934 for a long range flying boat and incorporated knowledge gleaned by a Kawanishi team that visited the Short Brothers factory in the UK, at that time one of the world's leading producers of flying boats, from building the Kawanishi H3K, a license-built, enlarged version of the Short Rangoon. The "Type S", as Kawanishi called it, was a large, four-engine monoplane with twin tails, a hull suspended beneath the parasol wing by a network of struts. Three prototypes were constructed, each one making gradual refinements to the machine's handling both in the water and in the air, fitting more powerful engines; the first of these flew on 14 July 1936 and was designated Navy Type 97 Flying Boat H6K. 217 would be built. H6Ks were deployed from 1938 onwards, first seeing service in the Sino-Japanese War and were in widespread use by the time the full-scale Pacific War erupted, in 1942.
At that time of the war, four Kōkūtai operated a total of 66 H6K4s. The type had some success over the South West Pacific. H6Ks had excellent endurance, being able to undertake 24-hour patrols, were used for long-range reconnaissance and bombing missions. From bases in the Dutch East Indies, they were able to undertake missions over a large portion of Australia. However, the H6K became vulnerable to a newer generation of heavier armed and faster fighters, it continued in service in areas where the risk of interception was low. In front-line service, it was replaced by the Kawanishi H8K. H6K1 Evaluation prototypes with four built. H6K1 Prototypes with 746 kW 1,000 hp Mitsubishi Kinsei 43 engines, three converted from the original H6K1 prototypes H6K2 Model 11 First production model. Includes two H6K2-L officer transport modification, 10 built. H6K2-L Unarmed transport version of H6K2 powered by Mitsubishi Kinsei 43 engines, 16 built H6K3 Model 21 Modified transport version of H6K2 for VIPs and high-ranking officers, 2 built H6K4 Model 22 Major production version, modified H6K2 with revised weapons, some with 694 kW Mitsubishi Kinsei 46 engines.
Fuel capacity increased from 7,764 L to 13,410 L. Includes two H6K4-L transport versions, 100 to 127 built. H6K4-L Transport version of H6K4, similar to H6K2-L, but with Mitsubishi Kinsei 46 engines, 20 built and another two converted from the H6K4 H6K5 Model 23 Fitted with 969 kW Mitsubishi Kinsei 51 or 53 engines and new upper turret replacing the open position, 36 built IndonesiaAir Service Volunteer Corps - A single H6K5 flying boat was restored to flight by Indonesian forces during the Indonesian War of Independence. JapanImperial Japanese Navy Air Service Imperial Japanese AirwaysUsed on the routes Yokohama-Saipan-Koror -Timor, Saigon-Bangkok and Saipan-Truk-Ponape-Jaluit Data from Warplanes of the Second World War, Volume Five: Flying Boats. Takeoff weight: 21,500 kg Powerplant: 4 × Mitsubishi Kinsei 43 or 46 14-cylinder, air-cooled, radial engines, 746 kW eachPerformance Maximum speed: 331 km/h Cruise speed: 216 km/h Range: 6,580 km Service ceiling: 9,610 m Rate of climb: 370 m/min Wing loading: 100 kg/m2 Power/mass: 0.17 kW/kg Armament 1× 7.7 mm Type 92 machine gun in nose 1× Type 92 machine gun in spine 2× Type 92 machine guns in waist blisters 1× 20 mm Type 99 cannon in tail turret 2× 800 kg torpedoes or 1,000 kg of bombs Related development Short Rangoon Kawanishi H3KAircraft of comparable role and era Aichi H9A Blackburn Sydney Consolidated PBY Catalina Dornier Do 24 Latécoère 300 Martin M-130 Potez-CAMS 141 Related lists List of aircraft of World War II List of military aircraft of Japan List of seaplanes and flying boats Notes Bibliography Kawanishi H6K on www.militaryfactory.com Duel between an HK6 and 2 B-17s
The Nakajima Ki-27 was the main fighter aircraft used by the Imperial Japanese Army Air Force up until 1940. Its Allied nickname was "Nate", although it was called "Abdul" in the "China Burma India" theater by many post war sources. In 1935, the Imperial Japanese Army held a competition between Nakajima and Kawasaki to design a low-wing monoplane to replace the Kawasaki Ki-10 biplane; the new fighter was to have a better performance than the experimental Mitsubishi Ki-18. The results were the Nakajima Ki-27, the Kawasaki Ki-28, the Mitsubishi Ki-33; the Nakajima design was based on its earlier Ki-11 monoplane fighter which lost to the Ki-10 in the Type 95 Fighter competition. When the follow-up Nakajima Ki-12 proposal with a liquid-cooled engine and retractable landing gear was deemed too complex by the Japanese officials, the Ki-27 was designed by Koyama Yasushi to have an air-cooled radial engine and fixed landing gear; the aircraft had the Nakajima trademark wing with a straight leading edge and tapered trailing edge which would reappear again on the Ki-43, Ki-44, Ki-84.
The Ki-27 made its first flight on 15 October 1936. Although it had a slower top speed and worse climb performance than its competitors, the Army chose the Nakajima design for its outstanding turning ability granted by its remarkably low wing loading; the Army ordered 10 pre-production samples for further testing, which featured an enclosed cockpit with sliding canopy and larger wings. The type was accepted into service in 1937 as the Army Type 97 Fighter. In addition to Nakajima, the Ki-27 was manufactured by Tachikawa Aircraft Company Ltd and Manshukoku Hikoki Seizo KK, with a total of 3,368 built before production ended in 1942; the Ki-27 was the Imperial Japanese Army Air Force's main fighter until the start of World War II. When placed into combat service over northern China in March 1938, the Ki-27 enjoyed air superiority until the introduction of the faster Soviet-built Polikarpov I-16 fighters by the Chinese. In the 1939 Battle of Khalkhin Gol against the USSR in Mongolia, the Ki-27 faced both Polikarpov I-15 biplane and Polikarpov I-16 monoplane fighters.
In the initial phase of the conflict, its performance was a match for the early model I-16s, was superior to the I-15 biplane. With better trained Ki-27 pilots, the IJAAF gained aerial superiority; the Ki-27 was armed with two 7.7 mm Type 89 machine guns and as with most aircraft of the period, lacked armor protection for the pilot and self-sealing or fire suppression in the fuel tanks. The Soviet Air Force received improved I-16s; the faster, more armed and armored I-16 now nullified the Ki-27's advantages and it could now escape from the Ki-27 in a dive. The VVS introduced new tactics consisting of flying in large knit formations, attacking with altitude and/or speed advantage and hit-and-run tactics much as Claire Chennault would formulate for the 1941-era Flying Tigers. Japanese losses mounted but despite this they claimed 1,340 aircraft. Japanese losses numbered 120 while the Russians claimed 215 vs. a peak Japanese strength of 200 fighters. Top scoring pilot of the incident and top scoring IJAAF pilot on the Ki-27 and overall World War II IJAAF ace was Warrant Officer Hiromichi Shinohara, who claimed 58 Soviet planes whilst flying Ki-27s, only to be shot down himself by a number of I-16s on 27 August 1939.
The preference of Japanese fighter pilots for the Ki-27's high rate of turn caused the Army to focus excessively on manoeuvrability, a decision which handicapped the development of faster and more armed fighters. The Ki-27 served until the beginning of World War II in the Pacific, escorting bombers attacking Malaya, Netherlands East Indies and the Philippines; the type saw extensive action against the American Volunteer Group in the early months of the war. Soon outclassed by the American Curtiss P-40 Warhawks, the Ki-27 was replaced in front line service by the Nakajima Ki-43, while surviving examples continued to serve as a trainer; the Ki-27 was exported for use with Manchukuo and Thai armed forces, seeing combat with both. In Thai service, Ki-27s damaged two North American P-51 Mustangs and shot down one Lockheed P-38 Lightning. In the final months of the war, desperate lack of aircraft forced the Japanese to utilize all available machines and the Ki-27 and 79 were no exception; some were equipped with up to 500 kg of explosives for kamikaze attacks, but some were redeployed as fighters, suffering terrible losses as on 16 February 1945 when the 39th Educational Flight Regiment scrambled 16 Ki-79 trainers from Yokoshiba Airfield to oppose a massive air raid from U.
S. Task Force 58 carrier group, losing six aircraft with more damaged and five pilots killed, in return damaging at least one Hellcat and downing a second. Data from Nakajima Army Type 97 Fighter Long Army designation for the Ki-27 Nakajima Type PE Private-venture experimental aircraft with Nakajima Ha.1a engine
Type 97 81 mm infantry mortar
The Type 97 81 mm infantry mortar was a Japanese mortar used primary by Imperial Japanese Army during World War II. The Type 97 designation was given to this gun as it was accepted in the year 2597 of the Japanese calendar, it entered service in 1937. Japanese infantry units are equipped with 81-mm mortars; the Type 97 81 mm mortar is commonly used and is referred to by the Japanese as an "Infantry Gun", which breaks down into 3 sections for transport. The markings which appear on the base of the barrel read "97 model small trench mortar."The modified version used by Imperial Japanese Navy with designation Type 3 mortar was used by naval land forces and as anti-submarine weapon on escort ships since 1943. The Type 97 is a smooth muzzle-loading weapon, it has a fixed firing pin in the breech assembly, the percussion of the propelling cartridge of the mortar shell against the firing pin propels the shell from the mortar. As many as six propellant increments can be attached to the fins of the mortar shell for the purpose of increasing the range.
The mortar and its calibre had its origin as all 81.4 mm, 82 mm or "8 cm" mortars in the French Brandt mle 27 81.4 mm mortar. The improved version Brandt Mle 27/31 had become the basis for copies, near-copies and license-built mortars all over the world; the Brandt mortars. A captured Type 97 mortar, studied in detail, was marked "Type 97 High-Angle Infantry Gun"; the weapon was manufactured in 1942 in the Osaka Army Arsenal. Although the Japanese weapon resembles the US 81-mm mortar, M1, there are several identifying features by which the two can be distinguished; the adjusting nut of the Japanese mortar is on the right bipod leg. Other differences are the buttress-type threads on the traversing and elevating screws of the Japanese weapon, as well as the use of welding to fasten bipod legs to the clevis joint and grease fittings dissimilar to those used by the US model; the collimator sight for the Type 97 Japanese mortar is heavier and more complicated than that utilized on the US 81-mm mortar Ml.
The Japanese sight examined was made of steel, except for the brass bushings used for the elevating and cross-leveling screws. A US M4 sight may be fitted to the Japanese weapon by shimming the sight bracket slightly; the Type 97 mortar examined had an extension fitted to the sight, raising the latter to the level of the muzzle of the mortar. This extension was added to permit sighting of the weapon when it was dug in or in defilade. Elevation scale of the sight is graduated in 50-mil intervals from 700 to 1,600 mils, a micrometer drum enables elevation readings to be made to the nearest mil; the collimator can be traversed in a full circle, the azimuth scale is calibrated in 100-mil graduations in two sections of 3,200 mils each. As in the case of elevation, a micrometer drum permits azimuth readings to be made to the nearest mil. There is a throw-out lever for rapid traverse of the collimator, which may be placed at an angle of elevation and locked in position by a series of meshing notches.
There are no open sights for rough laying of the piece. Ammunition recovered for the Type 97 thus far is the Type 00 HE shell; this shell is 12.87 inches long and weighs 6.93 pounds, 1 pound of, the weight of the TNT filler. The fuze is of the instantaneous type, which can be set for delay action, however, by the insertion of a delay pellet in the fuze nose prior to firing; the shell can be fired in the US 81-mm mortar M1, but the range will be about 10 per cent shorter than achieved with the US M43 and M43A shells. A firing test of Japanese shells in the US 81-mm M1 weapon gave the following results that cannot be regarded as wholly conclusive in view of deterioration of the shells; the 81mm mortar was used to launch an unusual AA Mine Discharger shell. Specifications of the weapon are as follows: War Department Special Series No 30 Japanese Mortars and Grenade Dischargers 1945 War Department Handbook on Japanese Military Forces 1 October 1944 War Department TM-E 30-480 Handbook on Japanese Military Forces at hyperwar.org A Type 100 81mm mortar round at inert-ord.net
Type 97 torpedo
The Type 97 was a 17.7 inches diameter torpedo used by the Imperial Japanese Navy during World War II. Intended for use with Japan's Ko-hyoteki class midget submarines, the torpedo was based on the 24-inch diameter Type 93 "Long Lance" used by Japanese surface vessels, but redesigned to meet the smaller 18-inch physical dimensions of the midgets' two torpedo tubes. Larger Japanese submarines were armed with the 21-inch Type 95 torpedo, it was not a great success. Its first operational use was in the attack on Pearl Harbor, after which it was modified as the Type 97 Special, sometimes known as the Type 98, it had a range of 3.4 miles at 44 knots. Four Type 97 Special torpedoes were fired during the Japanese midget submarine raid on Sydney Harbour in the early hours of June 1, 1942. Two were fired by the midget M-24 and aimed at the American heavy cruiser USS Chicago tied to the No 2. Buoy at Garden Island in Sydney Harbour. Both missed. One struck the harbour wall beneath the depot ship HMAS Kuttabul, sinking the converted ferry and killing 19 Australian and 2 British sailors aboard.
The second failed to arm, ran harmlessly aground at Garden Island. The remaining two were fired in Sydney Harbour by the midget M-21; the timing of their firing and their target, if any, are unknown. M-21 had been rammed and depth charged by HMAS Yandra at the entrance to Sydney Harbour around 2300 on May 31, but managed to recover sufficiently to enter the harbour at 03:01 on June 1. M-21 was cornered and sunk at 05:15 on June 1 in Taylors Bay inside Sydney Harbour; when the wreck was raised on June 4, both torpedoes had been fired. However the bow caps covering the torpedo tubes failed to drop clear, instead remaining caught in the buckled bow cage of the submarine; the No. 1 torpedo travelled three feet clear of the tube before jamming. The No. 2 torpedo travelled 18 inches. Elbourne, Sean. "Wonderful Kuttabul - a long history of service". Sea Talk. Royal Australian Navy. Pp. 11–19. Archived from the original on 2008-10-04. Retrieved 2008-09-07. Grose, Peter. A Very Rude Awakening. Crows Nest: Allen & Unwin.