British
13.5"/30 (34.3 cm) Marks I, II, III and IV
Updated 19 July 2006
Also known as the "67 ton" gun.  Owing to delays in manufacturing such a large gun, the completion of four ships of the "Admiral" class were greatly delayed, taking some six to seven years to commission.  Part of the delay was due to defective liners which cracked during proofing and which were extremely difficult to replace.

One gun was modified by adding a trunnion bend and then installed in a disappearing mount at the Plymouth defenses around 1900.  During World War I, when the stocks of old 13.5" (34.3 cm) shells ran out, Revenge had her guns relined down to 10" (25.4 cm), which were then designated as 10"/40 (25.4 cm) Mark VIII.

Construction was gradually improved as the series went on, with a reduction in the number of components.  The differences between Mark numbers was limited to slight details of construction.  All marks were interchangeable.  The breech was an early interrupted screw type that completely detached from the barrel when opened.  In total, 4 Mark I, 13 Mark II, 54 Mark III and 5 Mark IV guns were manufactured.
WNBR_135-30_mk1_Royal_Sovereign_pic.jpg

After guns on HMS Royal Sovereign
Note the open nature of this barbette mounting
WNBR_135-30_mk1_Royal_Sovereign_side_pic.jpg

13.5" (34.3 cm) guns on a Royal Sovereign Battleship
Note the loading pits at the rear of the guns
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Gun Characteristics
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Designation 13.5"/30 (34.3 cm) Marks I, II, III and IV
Ship Class Used On Middle "Admiral" and Royal Sovereign Classes
Date Of Design about 1880
Date In Service 1885
Gun Weight 67 tons (69 mt)
Gun Length oa 433.2 in (11.003 m)
Bore Length 338 in (8.585 m)
Rifling Length N/A
Grooves 34
Lands N/A
Twist Uniform RH 1 in 30
Chamber Volume N/A
Rate Of Fire 0.3 - 0.5 rounds per minute
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Ammunition
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Type Bag
Projectile Types and Weights AP - 1,250 lbs. (600 kg)
Bursting Charge 84.5 lbs. (38.3 kg)
Projectile Length N/A
Propellant Charge 630 lbs. (286 kg) SBC (Slow Burning Cocoa)
187 lbs. (84.8 kg) Cordite
Muzzle Velocity SBC charge:  2,016 fps (614 mps)
Cordite charge:  2,099 fps (640 mps)
Working Pressure N/A
Approximate Barrel Life N/A
Ammunition stowage per gun
(see Note)		 80 rounds
Note:  As approved on 30 June 1891 stowage was 20 AP, 12 Palliser, 39 common and 10 shrapnel per gun.
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Range
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Elevation With 1,250 lbs. (600 kg) projectile
Range @ 13.5 degrees
SBC charge		 11,950 yards (10,930 m)
Range @ 13.5 degrees
Cordite charge		 12,620 yards (11,540 m)
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Armor Penetration with 1,250 lbs. (600 kg) Projectile
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Range Vertical Iron Plate
1,000 yards (910 m) 28 in (71.1 cm)
Range Krupp Steel
3,000 yards (2,740 m) 11 in (27.9 cm)
Note:  Data from "British Battleships:  1850 - 1950" and "Warship Volume IV" article.
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Mount / Turret Data
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Designation Twin Barbette Mountings (2)
Weight N/A
Elevation about -3 / +13.5 degrees
Rate of Elevation N/A
Train -135 / +135 degrees
Rate of Train N/A
Gun Recoil N/A
Loading Angle N/A
Note:  Guns needed to be trained to 0 degrees in order to load.
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Data from
"Warrior to Dreadnought:  Warship Development 1860-1905" by D.K. Brown
"The Magnificent 7:  The Royal Sovereign Class of 1889" article by R.A. Burt in "Warship Volume IV"
"British Naval Guns 1880-1945 No 2" article by John Campbell in "Warship Volume V"
"The Big Gun:  Battleship Main Armament 1860-1945" by Peter Hodges
"British Battleships:  1850 - 1950" by Oscar Parkes