QF 4 inch Mk XVI naval gun

The QF 4 inch Mk XVI gun was the standard British Commonwealth naval anti-aircraft and dual-purpose gun of World War II.

Service
The Mk XVI superseded the earlier QF 4 inch Mk V naval gun on many Royal Naval ships during the late 1930s and early 1940s. These guns were usually mounted on HA/LA Mark XIX twin mountings, although several Australian frigates and corvettes had single-gun Mk XX mountings.

As secondary armament (list not complete):
 * HMS Hood
 * HMS Rodney
 * HMS Barham, HMS Malaya, HMS Warspite
 * s
 * s
 * HMS Exeter
 * s
 * s
 * s
 * s (Town-class)
 * Arethusa-class cruisers
 * s
 * Leander-class cruisers
 * HMS Effingham (D98)
 * HMS Danae (ORP Conrad)
 * Tribal-class destroyers

As main armament (list not complete):
 * Aircraft carriers: HMS Furious, HMS Unicorn
 * Escort carriers: s, HMS Pretoria Castle, HMS Activity
 * s (converted to anti-aircraft cruisers)
 * s
 * (the first series L: HMS Gorham, Lance, Legion, Lively)
 * HMS Petard (modified)
 * s
 * s (after WAIR modification - 15 ships)
 * HMS Wallace (after WAIR modification)
 * Hunt-class destroyers
 * Some s (single-gun Mk XX mounting)
 * s
 * s
 * (modified)
 * (modified)
 * Bay-class frigates
 * River-class frigates (part of Canadian-built)
 * 8 auxiliary AA defence ships
 * Some landing ships

Allied ships modified in the United Kingdom:
 * ORP Błyskawica (Polish)
 * HNLMS Jacob van Heemskerck (1939) (Dutch)
 * HNLMS Isaac Sweers (Dutch)
 * 4 French Elan-class avisos and s

The South African Navy Loch-class frigates (HMSAS Good Hope, HMSAS Natal and HMSAS Transvaal) each had two of these guns mounted on a twin Mark XIX on their foredeck between 1944 and 1976.

Surviving examples

 * On HMCS Haida (G63), Hamilton, Ortario, Canada.
 * Naval Museum of Alberta, Canada
 * On HMS Belfast (C35), London.
 * On ORP Błyskawica, Gdynia (re-bored to 100 mm).
 * A pair at South African National Museum of Military History, Johannesburg
 * A pair in a turret from INS Haifa (K-38), at Clandestine Immigration and Naval Museum, Haifa, Israel.
 * Two single guns on HMAS Diamantina (K377), Brisbane, Australia