An experimental gun begun shortly after the end of World War I and sometimes confused with the 46 cm/50 (18.1") 5th Year Type. Two prototypes were produced at the Kure Navy Yard, but the first one split during test firing. Work on the project was halted by the Japanese signing of the Washington Naval Limitation Treaty which prohibited large-caliber weapons. This project was restarted in November 1935 to test the protection system of what became the Yamato class battleships.

The second gun was found by the US occupation forces at the Kamegakubi proving grounds in December 1945. It was apparently destroyed a short time later.

The Japanese referred to this gun only as the 36 cm/45 5th Year Type in an effort to hide its true size.

Type 91 projectiles were made for this weapon in 1941 and at least one was found in the magazines at the Kamegakubi proving grounds after the war. No test data for these projectiles was found by post-war US Navy inspectors, which may mean that no test shots were ever performed before the program was cancelled at the start of the Pacific War.

Few details are available on this weapon, but it was wire wound only near the breech and had a slim chase, with a diameter at the muzzle of about 29 inches (73.7 cm). The cradle and slide were apparently developed from the British 15"/42 (38.1 cm) Mark I.

Gun Characteristics

Designation 36 cm/45 (14.2") 5th Year Type (Model 1916)
Official Designation: 45 caliber 5 Year Type 36 cm Gun
Actual Size - 48 cm/45 (18.9")
Ship Class Used On Experimental
Date Of Design about 1915
Date In Service Not in Service
Prototype testing started in November 1920
Gun Weight N/A
Gun Length oa N/A
Bore Length about 850 in (21.600 m)
Rifling Length N/A
Grooves N/A
Lands N/A
Twist N/A
Chamber Volume N/A
Rate Of Fire N/A
Powder Charge N/A


Type Bag
Projectile Types and Weights Type 91 APC - about 3,800 to 3,900 lbs. (1,724 to 1,770 kg)
Bursting Charge N/A
Projectile Length 81 in (206 cm)
Propellant Charge N/A
Muzzle Velocity N/A
Working Pressure N/A
Approximate Barrel Life N/A
Ammunition stowage per gun N/A

APC Type 91 projectiles were developed for this weapon during the 1930s. These differed from the normal design by having only one driving band.


Range of APC projectiles
Elevation Range
30 degrees about 36,000 yards (32,920 m)

Mount/Turret Data

Designation N/A (not planned for any ship)
Weight N/A
(see Note)
Elevation Rate N/A
Train N/A
Train Rate N/A
Gun recoil N/A


"Naval Weapons of World War Two" by John Campbell
"Japanese Cruisers of the Pacific War" by Eric Lacroix and Linton Wells II
"Japanese Warships of World War II" by A.J. Watts
US Naval Technical Mission to Japan report O-19: Japanese Projectiles General Types
US Naval Technical Mission to Japan report O-45 (N): Japanese 18" Gun Mounts

Page History

23 December 2006 - Benchmark
29 November 2009 - Added information about Type 91 projectile
27 May 2012 - Updated to latest template
15 December 2015 - Added a few details
01 November 2016 - Converted to HTML 5 format