QF 4 inch naval gun Mk I – III

The QF 4-inch gun Mks I, II, III were early British QF (quick-firing) naval guns originating in 1895. They all had barrels of 40 calibres length.

Country Name Origin Year
United Kingdom - UK (Great Britain) 1896
Country Name Operational Year Retirement Year
Ireland 1896 1920 View
United Kingdom - UK (Great Britain) 1896 1920 View

The gun was intended to be a more powerful alternative to the quick-firing 3-inch QF 12-pounder gun, and a faster-firing replacement for the BL 4-inch gun.

It was mounted on the following ships :

  • Pelorus-class third-class protected cruisers of 1896
  • Condor-class sloops of 1898
  • Cadmus-class sloops of 1900
  • Topaze-class third-class cruisers, launched in 1903
  • Invincible-class battlecruisers of 1906

Its 25-pound shell proved insufficiently powerful to make it much of an improvement on the 12-pounder. From 1907 onwards it was succeeded in its class on new warships by the BL 4 inch gun Mk VIII, which fired a 31-pound shell.

World War I land service

On 20 September 1914 the British cruiser HMS Pegasus was sunk by SMS Königsberg in Zanzibar harbour. Her 8 QF 4-inch Mk III guns were recovered and used ashore in the East African campaign. Some were used as coast defence guns at Zanzibar and Mombasa. Two guns, and from 11 February 1916, three guns, were used by 10th Heavy Battery manned by the Royal Marines, mounted on improvised field carriages and towed by Packard lorries, supported by six REO lorries carrying ammunition.

Type Naval gun
Coast defence gun
Place of origin United Kingdom of Great Britain and Ireland
Service history
In service 1896 - 1920
Used by British Empire
Wars Boxer Rebellion,
World War I
Production history
Designed 1895
Weight 2,912 pounds (1,321 kg) barrel & breech
Barrel length 160 inches (4.064 m) bore (40cal); 165.35 inches (4.200 m) total
Shell Separate-loading QF 25 pounds (11.34 kg) Common pointed or Lyddite
Calibre 4-inch (101.6 mm)
Breech Single-motion screw
Muzzle velocity 2,300 feet per second (700 m/s)
Maximum firing range 9,000 yards (8,200 m)

End notes