U.S. military intelligence report on the Japanese 150mm Type 89 (1929) Gun from Japanese Artillery Weapons, CINCPAC-CINCPOA, Bulletin 152-45, July 1945.
150 MM GUN TYPE 89 (1929)
The Japanese Type 89, 15 cm gun is comparable to the old U.S. M1918 in many respects, but it has a shorter range and is less efficient than similar caliber guns of other nations. Types 45 and 90, 15 cm guns have also been reported.
The Type 89 has a variable hydro-pneumatic recoil system and an interrupted thread breech block; the latter has a mushroom head and stepped-up buttress type screws. Two carriages have been recovered. The only apparent difference is in the two equilibrators. One has spring type and the other hydrospring type. The trail is the split box type with detachable trail spades. The traversing handwheel and scale are located on the left side of the carriage; the scale is graduated up to 350 mils in ten mil increments. The elevation scale, range drum, and sight are on the right side of the carriage; the range scale is graduated up to 42 degrees.
An 8 ton prime mover is used to tow the piece. For traveling, the gun is broken down in two loads, tube and carriage.
Caliber 149.1 mm (5.87 in.) Weight (firing position) 22,830 lbs. Length (firing position) 26 ft. 4 in. Length of bore 18 ft. 10 in. Muzzle velocity 2,870 ft/sec. Maximum range 21,800 yds. Elevation 42 degrees Depression 5 degrees Traverse 350 mils R & L Rate of fire 2 rds/min. Ammunition HE, APHE, Long pointed HE, Shrap., Illumi.