[Machine Translation] Mortars with a large caliber ranging from 5 to 30 centimeters and with a large angle of impact, firing a large number of explosive-laden projectiles. In the final stages of the Pacific War, jet propelled and recoilless guns were deployed for the protection of remote islands and for decisive battles on the mainland. The structure and function of a wide variety of special artillery guns, such as train guns and armored trains for coastal defense with a range of up to 50 km, which the Japanese Army had studied and equipped.