46cm/45 Type 94 . Sea Cannon


May 19, 2022

The "40cm/45 Type 94 Sea Gun" (四五口径九四式四〇糎砲, Yonjūgo-kōkei kyūyon-shiki yonjussenchi-hō) was the largest naval gun ever used by a battleship during World War II. Their actual caliber is 46 cm but is called 40 cm in order to conceal their true size.


Type 94 is a multi-tube casting gun with steel wire reinforcement. The cannon is used in a three-gun turret form with each Yamato equipping three turrets. When all guns and turrets were in place, they weighed a total of 2510 tons, equivalent to the mass of a destroyer of the time. The Japanese guns had a slightly larger barrel size than the British 18-inch Navy guns built during World War I, although the ammunition was not as heavy. Later, the British designed N3-class battleships with 18-inch guns but no ships were built, so the Allies did not have a gun equivalent to the Type 94. Unlike the heavy guns of the other navies. , they can fire special anti-aircraft bullets (Sanshiki) also known as "honeycomb" bullets.


About 27 guns were built for the three Yamato-class ships. Two-thirds of the guns were lost when the Yamato and Musashi were sunk. Each tube is molded then laminated in three stages. A half-length tube is nested on top of the first tube and shrunk. The entire finished product is then wire wound and two additional tubes shrink over the entire length of the previous tubes. A final inner tube is then inserted into the gun and expanded into place. This inner tube is then slotted to complete the gun. According to this design, the gun could not be slotted, but had to replace the entire barrel after wear. Unlike previous designs, the turrets, when inspected by a naval engineering team. American, had nothing in common with the British Vickers designs previously used in other Japanese battleships. The ammo and powder loading system was considered smart, although a bit too heavy for a relatively fast rate of fire. Each gun is mounted independently allowing for independent lifting.

Range and flight time

With Type 91 . anti-armor ammunition

Impact angle and velocity

With Type 91 . anti-armor ammunition

See more

BL 18 inch Mk I naval gun 18"/48 caliber Mark 1 gun 16"/50 caliber Mark 7 gun List of naval guns List of largest cannons by caliber


Scottish History - Mons Meg report mounted at sea Archived 2010-05-03 at the Wayback Machine 18.1"/45 caliber, Nihon Kaigun Japan 46cm/45 (15.9") Type 94 - Actual Size 46cm (18.1"), Navweaps.com PIECES LOURDES: 240 et plus, le.fantasque.free.fr Campbell, John (1985). Naval Weapons of World War Two. Naval Institute Press. ISBN 0-87021-459-4.

External links

40 cm/45 Type 94 naval gun related media at Wikimedia Commons