15"/42 (38.1 cm) Mark I

Updated 05 March 2016


15"/42 (38.1 cm) Mark I guns on exhibit at the Imperial War Museum in London
Photograph copyrighted by Axel K.
Click on this picture for a larger image

These are the last two of these guns still in existence above water.  As viewed from the breech end, the left gun (number 125 built) was installed on HMS Ramillies in 1916.  It was removed from that ship and stored in 1941.  The right gun barrel (number 102 built) was mounted on HMS Resolution from 1915 to 1938.  This gun was relined and then mounted on the monitor HMS Roberts in 1944.  The breech mechanism on the right-hand gun is of interest as it was once used for instructional purposes at the Woolwich Arsenal.

For a history of these weapons, see this Imperial War Museum Webpage


Forward Turrets on the HMS Queen Elizabeth
This photograph was taken in 1915 in the Dardanelles at the start of the Gallipoli campaign, the first time the 15"/42 (38.1 cm) guns were fired in combat
Note the sighting hoods and small base-length rangefinders on top of each turret and that the director is located below the bridge
IWM Photograph Q 13238


HMS Royal Oak
Good view showing both forward and broadside views of the Mark I Turrets


HMS Valiant in early 1930s
Note the longer base-length rangefinders on B and X turrets and the Fairey III-F floatplane on her fantail
U.S. Naval Historical Center Photograph # NH 52518


HMS Hood in the 1930s
Note the differences in these Mark II turrets - sighting ports instead of hoods, 30 foot (9.17 m) range finders used on all turrets and larger gun ports to allow 30 degree elevation
IWM photograph HU 67486


Bow of HMS Renown during World War II showing modernized Mark I*/N turrets
Note the armored hoods covering the enlarged gunports and that sighting ports have replaced the original sighting hoods
IWM photograph A 20419


HMS Vanguard
Compare this picture with the one above of Queen Elizabeth
Note the larger gun port openings and the 40 mm Bofors STAAG mounting atop "B" turret
Picture from the files of Shirley North, former crewmember of the Vanguard, and used here by his kind permission
Please Note: This picture can not be copied without the express permission of


Bow of HMS Vanguard
Note that this photograph was taken during the "Royal Tour" as a review box has replaced the STAAG mounting atop "B" turret
This photograph also shows portions of the three breakwaters used to shed water from the bow.  A major effort was made to make Vanguard a drier ship than the previous King George V class and she was given a raised bow, a bow flare, higher freeboard and these breakwaters.
IWM photograph A 31256


HMS Vanguard in September 1952
Note the belt armor, large turret rangefinders, larger 5.25" (13.4 cm) gunhouses, transom stern and the USA Mark 37 GFCS
U.S. Naval Historical Center Photograph # NH 103735


15" (38.1 cm) Mark I/N Turret being constructed for HMS Abercrombie
Photograph taken at Vickers-Armstrong's Elswick Works in December 1942
The 12 ton (12.2 mt) balance weights that were necessary for 30 degree elevation can be seen atop each gun.  At lower right can be seen a 13.5" (34.3 cm) gun.  The 15"/42 (38.1 cm) Mark I was largely based upon the design of this weapon.  The one shown here was probably being linered down to a high-velocity 8" (20.3 cm) gun - see 13.5"/45 Mark V data page for further details.


HMS Abercrombie in April 1943 following her completion
The tall barbette was to allow the battleship-sized turret stalk to be used without modifications and still maintain the shallow draft necessary for the monitor to move as close as possible to the coast


15"/42 gun barrel at the Coventry Ordinance Works
Note that the breech has not yet been engraved with identifying information
IWM Photograph Q 30139


15" (38.1 cm) Common Round on HMS Royal Oak in 1917
Note the lifting clamp and the protective cover on the driving bands
IWM photograph Q 17945


Model of Mark I Turret for HMS Queen Elizabeth at the Imperial War Museum, London, UK
Note the overlapping turret top plates, the turret race, the overhead "grabs" used to transfer shells out of storage to the stalk and from the lower to the upper hoist, and the hopper used to move cartridge bags from the magazine
Also note that shells were stored horizontally in bins.  This meant that any significant change in shell length - such as the change from 4crh to 6crh projectiles - required modifications to the storage bins.
IWM photograph MOD 296


Typical 15" (38.1 cm) projectiles of World War II
The left projectile is a Mark XXIIb APC 6crh while the right one is a Mark VIIIb HE 6crh
Sketch copyrighted by Ian Buxton and used here by his kind permission


Standard Charge Cartridge
Image courtesy of Steve Johnson of Cyberheritage

Images at The Vickers Photographic Archive

See 15 naval gun shop


Page History

06 August 2008 - Benchmark
14 February 2012 - Updated to latest template
02 April 2012 - Changed link to Wayback Archive, added photograph of Queen Elizabeth Turret Model
15 December 2013 - Added photograph of gun barrel
27 February 2014 - Added photograph of HMS Hood
29 June 2014 - Added bow photograph of HMS Vanguard
05 October 2014 - Added bow photograph of HMS Renown
01 December 2015 - Changed Vickers Photographic Archive links to point at Wayback Archive
05 March 2016 - Redid photograph of shell handling on HMS Royal Oak