36 cm/45 Type 41 (356 mm)

History

The 45 calibre 41 Type 36 cm Gun (45口径四一式36cm砲) was the main gun famously used on the Kongō-class battlecruisers along with the Ise and Fusō-class battleships. It shared a piece of history with the 50 calibre 41 Type 15 cm Gun, being originally introduced with the Kongō battlecruiser, at the time the highest calibre naval guns in service of any country in the world. First units were manufactured in the UK by Vickers, while the remaining was constructed at the Kure Naval Arsenal, for a total of over 100 guns of the type being built until the end of World War 2.

Being widely used type of gun, they have seen a number of modifications and modernisations over their lifetime.

During the inter-war period gun turrets were modified to increase the elevation from 33° to 43°. It was achieved by reconstructing the gunwell and lowering the revolving part of the turret's structure. This upgrade was completed for all ships with the Type 41 guns except for the aft-most guns on Ise and Hyūga, until both were eventually rebuilt to hybrid carriers, thus removing the problematic gun turrets.

Other upgrades included a new, double, longitudinal flashtight bulkheads separating the two guns in the turret or a new loading cages allowing a full set of charges to be loaded in a single stroke of the power rammer. Additionally in December 1937 an experimental sprinkler system was added to the battleship Ise, decreasing the risk of fire and catastrophic explosion.

The 36cm gun weighted 86 tonnes (for a total weight of 699t (Ise-type) or 664t (Haruna-type) turrets) and could fire shells with a muzzle velocity of 770—805m/s (depending on the mass of the shell) up to 35,500m away or 9,750m altitude (for anti-air duty).

Shells

The 36 cm Type 41 used several different shell types over its lifespan. Most of the development was focused on the armor-piercing shells, which were supplemented by two types of high explosive rounds, and, during the WW2, the Sanshikidan shells.

Armor-piercing

• Type 3 APC - Armor-piercing shell, officially adopted into service in 1917. It's marked after the year Taishō 3 (or 1914 Georgian calendar).
• Type 5 APC - An upgrade of the Type 3 shell using the lessons learnt for the German and British shells purchased by the Japanese after the Great War. Type 5 was officially adopted into service in 1925, designated after Taishō 5 (1916 Georgian calendar). It used an 0.2sec-delay Type 13 Mark 3 Short Delay Fuze.
• No. 6 APC - Adopted in 1928 was a further upgrade to the Type 5, it improved the shell behaviour below the water surface, improving the penetration below the water line, and decreased the probability of premature detonation.
• Type 88 APC - Had no changes in relation to No. 6, it's just a redesignation made in 1931.
• Type 91 APC - A new type of the shells introduced in 1931. Over time it completely replaced older types of the armor-piercing rounds. It used the 0.4sec-delay, Type 13 Mark 4 base fuze and Type 13 Mark 4 Mod 1 base fuze (modification decrease the probability of a fuze failure), in 1941 a new 0.4sec-delay Type 13 Mark 5 fuze was added. Number 91 stands for the 2591 Japanese Imperial year, which translates to 1931 in Georgian calendar.
• Type 1 APC - The last type of the armor-piercing shell used by the Type 41 guns. It was based on the Type 91, with added option to include a special dye that colored the splashes of the naval artillery. This allowed different warships to fire at the same target and still visually distinguish hit locations from different ships, even if the splashes were from the same caliber of the guns at the same time. Kongô used red dye, Haruna used black, while Hyuga never used one.

High-explosive and incendiary

• Common Projectile Type 3 HE (also known simply as "Common Capped") - was the shell type used by Japanese during the World War 1, being derived from the imported British shells. It was officially adopted into service in 1915 and has seen decades of use in the Japanese fleet being only replaced by WW2.
• Common Projectile Type 0 HE - filled with 65.1 lbs (29.5kg) of trinitroanisole (Type 91 explosive). Shell could be equipped in one of the fuzes: Type 4 Mod.1 (Mechanical Time Fuze), Type 0 (Mechanical Time Fuze), or nose contact fuze.
• Common Projectile Model 3 (sometimes confusingly referred to as a "Type 3") - Sanshikidan incendiary/anti-aircraft shell. Carried 735 incendiary tubes and 375 strays dispersing them at 15° cone over 213m burst. While being truly spectacular their real combat effectiveness was marginal at best.

Practice

An additional set of practice shells was built for the training exercises:

• Practice - from a converted WW-1 era high explosive shell
• Type 91 Practice - converted Type 91 APC
• Type 0 Practice - converted Type 0 HE