The QF 4 inch (102 mm) was a British naval gun dating from the First World War, which was adapted with suitable mountings for use as a heavy anti-aircraft artillery on land and at sea. During World War II, it was also used in the coastal defense. The length is 45 caliber (4.59 m) as ammunition came in the First World War, both two-piece bullet (projectile and charge separately) for Seezielgeschütze as well as one-piece cartridge ammunition (for the anti-aircraft) for use. All Mk V, built in 1918, used a one-piece shell.

Navy

This naval gun was introduced due to the higher rate of fire than replacing the BL 4-inch Mk VII.

The first use was learned in 1914 as secondary armament on the light cruisers Arethusa class. It was quickly adapted for use in Air Defense and was typically mounted on heavy cruisers and battleships.

From the 1930s, it was 4-inch Mk XVI superseded by new construction of these classes, the QF as an anti-aircraft gun, but found in many light cruisers and destroyers in World War II use.

Country

At the beginning of World War I, several guns of the Navy were made ​​for testing as anti-aircraft guns for home defense and the protection of essential objects. They were mounted on fixed platforms and proved to be quite successful after a one-piece cartridge was introduced in place of the original two-piece ammunition.

The anti-aircraft gun mount allowed for an elevation range of 80 °, but the reloading was impossible above 62 °. This reduced the maximum rate of fire considerably. At the time of the armistice, there were 24 guns in the UK and two in France for anti-aircraft defense in action. After the war, the guns were returned to the Navy.

Coastal Defense

Between 1915 and 1928, several guns were installed in the coastal forts that guarded the mouth of the Humber.

Mk XV

The Mark XV possessed, until the amended closure mechanism, the same performance as the Mk V. Two Mk V guns were tentatively reconstructed on the amended closure and used in a prototype twin gun mount; the 1931 was installed on the lower deck of HMS Resolution on tests. Of the six newly produced Mk XV-four guns were set up in 1936 in a newly-developed Mk XVIII twin guns on HMS Repulse. But tests revealed a miserable rate of fire, and the towers were removed in 1938.

Carriages

The open design of the gun crews offered little protection against foul weather, which mainly affected the rate of fire. All individual carriages were aligned by hand.