14"/45 (35.6 cm) Marks I and III
Updated 01 February 2014

The Chilean government had two battleships building in British yards at the start of World War I, Almirante Latorre and Almirante Cochrane, both armed with Elswick weapons.  These ships were taken over by the British in 1915, with Almirante Latorre being completed as the battleship HMS Canada and Almirante Cochrane becoming the aircraft carrier HMS Eagle.  At the end of the war, HMS Canada was sold back to Chile, once again named Almirante Cochrane, and served in the Chilean Navy until stricken in 1958.

The Mark I was an Elswick design of wire-wound construction with a three-motion short-arm breech mechanism.  Fourteen guns were produced with the four reserve guns, which were never used, differing in having a sharper taper on the inner A tube.  These spare guns were scrapped in 1922.  Ten additional guns were ordered for Almirante Cochrane and three of these were completed with railway mountings but never used in France.  The railway guns had the forward slope of their chambers reduced from 1 in 8 to 1 in 15 in order to prevent the shell from slipping back at high elevations.

The Mark III was the designation given to two guns built by Elswick and intended for the Japanese battleship Yamashiro but not delivered.  They are thought to be otherwise the same as other 14-inch (35.6 cm) guns built for the Japanese Navy.  The Mark III guns were altered to give a performance identical to the Mark I.  The main constructional differences were that they were about 1.5 tons (1.6 mt) lighter than the Mark I guns, had Vickers breech mechanisms, the inner A tube had forward shoulders with cannelured rings - to reduce "steel choke" - and were not tapered.  These Mark III guns were not used afloat but were used on railway mountings in France.

The muzzle velocity and shell weight of the 14" (35.6 cm) Mark I did not differ appreciatively from that of the 14" (35.6 cm) Mark VII carried by the King George V class battleships of World War II.  If anything, the older guns had slightly better performance considering that they fired shells of poorer aerodynamic qualities than did the newer guns (4crh vs. 6crh).

The data that follows is specifically for the Mark I guns used on HMS Canada although the Mark III should have had similar performance.


HMS Canada
IWM photograph SP 1938


HMS Canada
Cody Images Photograph

Gun Characteristics
Designation 14"/45 (35.6 cm) Mark I
14"/45 (35.6 cm) Mark III
Ship Class Used On Mark I:  HMS Canada (ex-Almirante Latorre)
Mark III:  Intended for IJN Yamashiro, but used as railway guns
Date Of Design 1910
Date In Service 1915
Gun Weight 84.75 tons (86.11 mt)
Gun Length oa 648.4 in (16.469 m)
Bore Length 630 in (16.002 m)
Rifling Length 529.8 in (13.457 m)
Grooves (84) 0.12 in deep x 0.394 in (3.05 mm x 8.86 mm)
Lands 0.174 in (4.42 mm)
Twist Uniform RH 1 in 30
Chamber Volume 23,500 in3 (385.1 dm3)
Rate Of Fire About 2 rounds per minute
Type Bag
Projectile Types and Weights APC Mark Ia - 1,586 lbs. (719 kg)
APC Mark IIIa (Greenboy) - 1,595 lbs. (723.5 kg)
CPC - 1,586 lbs. (719 kg)
HE - 1,586 lbs. (719 kg)
Bursting Charge APC Mark Ia - 61.4 lbs. (27.9 kg)
APC Mark IIIa - 37.5 lbs. (17.0 kg)
CPC - 105.3 lbs. (47.8 kg)
HE - 135.0 lbs. (61.2 kg)
Projectile Length N/A
Propellant Charge 344 lbs. (156 kg) MD45
Muzzle Velocity 2,500 fps (762 mps)
Working Pressure N/A
Approximate Barrel Life 350 rounds
Ammunition stowage per gun 100 rounds
Range With 1,586 lbs. (719 kg) APC Mark Ia Shell
MV = 2,475 fps (754 mps)
Striking Velocity
Angle of Fall
1.20 degrees
2,500 yards (2,290 m)
2,293 fps (699 mps)
2.40 degrees
5,000 yards (4,570 m)
2,114 fps (644 mps)
4.00 degrees
7,500 yards (6,860 m)
1,948 fps (594 mps)
5.65 degrees
10,000 yards (9,140 m)
1,798 fps (548 mps)
7.53 degrees
12,500 yards (11,430 m)
1,663 fps (507 mps)
9.65 degrees
15,000 yards (13,720 m)
1,546 fps (471 mps)
12.03 degrees
17,500 yards (16,000 m)
1,452 fps (443 mps)
14.66 degrees
20,000 yards (18,290 m)
1,388 fps (423 mps)
17.60 degrees
22,500 yards (20,570 m)
1,347 fps (411 mps)
19.55 degrees
24,000 yards (21,950 m)
1,336 fps (407 mps)
20.00 degrees
24,400 yards (22,310 m)
Armor Penetration with 1,586 lbs. (719 kg) AP Projectile
Range Vertical Iron Plate
0 yards (0 m) 53.2 in (135.1 cm)
Note:  Data from "British Battleships:  1850 - 1950."
Mount / Turret Data
Designation Two-gun Turrets
   Canada (5):  Mark I
Weight 660 tons (671 mt)
Elevation -3 / +20 degrees (one source says -5 degrees)
Rate of Elevation 3 degrees per second
(see Note 2)
Forward and aft turrets:  about -150 / +150 degrees
Q turret:  about 30 to 150 degrees on either side
Rate of Train 3 degrees per second
Gun Recoil 45 in (114 cm)
Loading Angle Any angle

1) These mountings were produced by the Elswick works.  Their design and operation were very similar to their previous "12-in Special" design for the HMS Agincourt except that they used Kenyon doors instead of shell bogies.

2) Superfiring turrets could not fire within 30 degrees of the axis because the blast effects would have penetrated into the lower turrets through the sighting hoods.

3) Gun axes were 100 in (254 cm) apart.

Data from
"The Grand Fleet:  Warship Design and Development 1906-1922" by D.K. Brown
"British Battleships of World War One" by R.A. Burt
"Jutland:  An Analysis of the Fighting," "Naval Weapons of World War Two" and "British Naval Guns 1880-1945 No 1" article in "Warship Volume V" all by John Campbell
"The Big Gun:  Battleship Main Armament 1860-1945" by Peter Hodges
"Battleships of World War I" by Peter Hore
"British Battleships:  1860 - 1950" by Oscar Parkes
"British Battleships of World War Two" by Alan Raven and John Roberts
ADM 186/169
Special help by Neil Stirling
Page History

23 July 2007 - Benchmark
30 January 2009 - Fixed minor typographical errors, added note about chamber slope for railway guns
01 February 2014 - Replaced photograph, added ammunition information