Type 4 hand grenade
| Type 4 hand grenade | |
|---|---|
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| General Information | |
| Type: | Frag grenade |
| Country of origin: |
 Japan
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| Commissioning: | 1944 |
| Working time: | 1944 to 1945 |
| Technical specifications | |
| Combat weight: | approx. 455 grams |
| Charge: | approx. 100 grams of type 88 explosives |
| Diameter: | approx. 76 millimeters |
| Height: | approx. 102 millimeters |
| Detonator: | Friction igniter |
| Lists on the subject | |
The type 4 grenade ( Japanese 四 式 陶製 手 榴 弾 Yon-shiki tōsei teryūdan , German 'Type 4 ceramic grenade' ) was a fragmentation hand grenade designed as an emergency weapon , which was developed and used by the Imperial Japanese Navy towards the end of the Second World War .
history
At the end of 1944, the industrial infrastructure of Japan was largely destroyed by Allied bombing and the sea blockade resulted in an increasing shortage of raw materials. The lack of metals for mass production of hand grenades in huge quantities for the defense of Japan against the expected invasion of the Allies ( Operation Downfall were needed), the Technical Development Bureau of the Imperial Japanese Navy developed a cheap, easy to produce from domestic raw materials grenade from Ceramic or porcelain . The kilns required for the fire of the type 4 grenades , in which the famous traditional Japanese porcelain such as Imari porcelain from Arita (Saga) , Bizen ceramics or ceramics from Seto (Aichi) were burned, were used again for the production of ceramic grenades Service provided. After the fire, the grenades were equipped with explosive charges and detonators at the Asano Carlit company in Kawagoe and delivered to the army. The type 4 grenades were produced in large numbers and, depending on the local clay and type of kiln, with a wide range of shapes, sizes and colors, so the colors of the shards ranged from white to red to brown, depending on the pottery. The grenades were unglazed, some were hard-fired like stoneware, or with a transparent, brown or almost black glaze .
technology
The type 4 grenade was spherical round with a protruding neck, a delay fuse, which was covered with a rubber cap for safety. The splinter body was made of ceramic, terracotta or porcelain materials with a height from the floor to the top of the neck of 4 ″ ≈ 101.6 mm, a diameter of 3 ″ ≈ 76.2 mm and a wall thickness of 7 ⁄ 14 ″ ≈ 12.7 mm. The detonator consisted of a rubber sleeve inserted into the grenade, which was wedged against the neck of the grenade with an inserted wooden ring. A friction body made of a mixture of sand and potassium chlorate was attached to the top of the igniter, which, like matches , could be ignited by friction. Underneath followed a delay charge of black powder with a burning time of about 4 to 5 seconds. A detonator attached to this delay set, consisting of a lead azide paste, formed the detonator , which ignites the actual explosive charge of the grenade via a boosting charge made of Trotyl . The load on the grenade was 3.5 oz. ≈ 99 g of a laboratory which was designated " Type 88 ". This consisted of a mixture of 66% ammonium perchlorate , 16% ferrosilicon powder , 12% wood chips and 6% oil as a binding or phlegmatizing agent . The latter should increase transport and handling safety. The total mass of the grenade was about 16 oz. ≈ 454 g. To ignite the grenade, the rubber cap contained a small wooden cap with a special friction surface coating with which the grenade was ignited on the friction igniter.
Calls
The Type 4 grenades were issued in large quantities to civil defense organizations such as voluntary combat units, Yokusan Sōnendan and reservist units involved in preparations to repel an expected invasion of the Japanese islands by Allied forces. But they were also delivered in large quantities to the front troops , where they were used, for example, in the battles of Iwo Jima and Okinawa .
literature
- US Department of War (Ed.): Handbook on Japanese Military Forces . TM-E 30-480. Louisiana State University Press, 1994 (first edition: 1945, reprint, ISBN indicated with: 0-8071-2013-8).
- Departments of the Army and the Air Force (Eds.): Japanese Explosive Ordnance . TM 9-1985-4, 1953, pp. 228 (English).
- New Weapons Captured at Ormoc . In: Military Intelligence Service (ed.): Intelligence Bulletin . No. III , February 6, 1945, p. 70-71 (English).
Individual evidence
- ↑ Type 4 ceramic hand grenade at ww2technik.de
- ↑ Departments of the Army and the Air Force (ed.): Japanese Explosive Ordnance . TM 9-1985-4, 1953, pp. 228 (English).
- ^ New Weapons Captured at Ormoc . In: Military Intelligence Service (ed.): Intelligence Bulletin . No. III , February 6, 1945, p. 70-71 (English).
Web links
- Type 4 ceramic hand grenade on ww2technik.de
- Type 4, HE on Inert -Ord.Net (English)
- Digital 360 ° reconstruction of a type 4 grenade on Visualizing a Wired World's Past