A diagram of a Type 98 No.25 "Land Bomb" showing the typical construction of Japanese Navy land bombs, a thin walled steel cylinder with a nose and tail screwed and welded on.
The Japanese navy produced a large number of different types of bombs, these were sub-divided into three main categories:
Land bombs - for use against land targets. They were normally not produced to a high standard consisting of a simple cylindrical case, riveted or welded to a cast steel nose.
Ordinary bombs - for use against ships. They were produced in general purpose and semi-armor-piercing types. They were of higher quality and generally had a smooth machined case
Special bombs - for various purposes.
Color coding system
Bombs
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Ordnance used in Pearl Harbor attack. Left: Type 98 #25 land bomb. Middle: Type 91 modification 2 Torpedo. Right: Type 99 #80 Mark 5 High-altitude armor-piercing bomb.
Rocket bombs
The Japanese produced a number of bombs with rocket motors installed, intended for air-to-air use against bomber formations, or as armor-piercing weapons. Only two saw service, the Type 3 No.25 Mk 4 armor-piercing rocket bomb, and the Type 3 No.6 Mk.27 air-to-air rocket bomb.
Japanese Navy bomb fuzes designation system was unknown to the Allies until after the end of the Second World War. As a result, a designation system was created to describe the fuzes as follows. It consists of a capital letter, a numeral and a lower-case parenthetical letter.
The capital letter designates the fuzes type as follows:
A - nose impact
B - tail impact
C - long delay fuze
D - airburst fuze
E - protective fuze
The numeral approximates the order in which the fuzes were captured by the allies. Finally the lower-case letter in parentheses indicates the different but similar designs.
Where possible the original Japanese designation is given.
