14 cm/40 11th Year Type naval gun

The 14 cm/40 11th Year Type naval gun was the standard surface battery for Japanese submarine cruisers of World War II. Most carried single guns, but Junsen type submarines carried two. Japanese submarines I-7 and I-8 carried an unusual twin mounting capable of elevating to 40°. Eleventh year type refers to the horizontal sliding breech block on these guns. Breech block design began in 1922 AD, the eleventh year of the Taishō period. The gun fired a projectile 14 cm in diameter, and the barrel was 40 calibers long (barrel length is 14 cm x 40 = 560 centimeters or 220 inches).

Coastal bombardment of North America
This gun was the weapon used by I-17 to sink SS Emidio and to later shell the Ellwood Oil Field near Santa Barbara, California. It was also used by I-25 for the Bombardment of Fort Stevens in Oregon near the mouth of the Columbia River and by I-26 to shell the Estevan Point lighthouse in British Columbia.

Similar weapon
A longer-barreled 14 cm/50 3rd Year Type naval gun was used aboard surface ships and for coastal defense. The 40 caliber 11th Year Type guns were intended for use against destroyers, and fired base-fuzed projectiles with thinner shell walls allowing a larger bursting charge than the 50 caliber 3rd Year Type guns for potential use against armored ships. The lower velocity 40 caliber gun had a useful life expectancy of 800 to 1000 effective full charges (EFC) per barrel.