Japan
46 cm/45 (18.1") 5th Year Type
Updated 23 June 2012
Planned for the never built "13" class battleships of the 8-8-8 plan, none of these guns were ever built.  Sometimes confused with the prototype 48 cm (18.9") 5th Year Type gun built in the early 1920s.  All work on guns of these sizes was halted by the Washington Naval Limitation Treaty and the ships were cancelled in the Spring of 1922.
WNJAP_18-45_t5_sketch.jpg

Sketch of "13" from "Japanese Warships of World War II" by A.J. Watts
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Gun Characteristics
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Designation 46 cm/45 5th Year Type (Model 1916)
Ship Class Used On "13" Class Battleships (Battleships 39-42, also known as Battlecruisers 13-16)
Date Of Design about 1918
Date In Service N/A (planned for completion in 1927)
Gun Weight N/A
Gun Length oa N/A
Bore Length about 815 in (20.700 m)
Rifling Length N/A
Grooves N/A
Lands N/A
Twist N/A
Chamber Volume N/A
Rate Of Fire about 1.5 rounds per minute
Powder Charge N/A
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Ammunition
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Type Bag
Projectile Types and Weights AP - about 3,000 lbs. (1,360 kg)
Bursting Charge N/A
Projectile Length N/A
Propellant Charge N/A
Muzzle Velocity N/A
Working Pressure N/A
Approximate Barrel Life N/A
Ammunition stowage per gun About 60 rounds
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Range
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Elevation about 3,000 lbs. (1,360 kg) AP Shell
Range @ 30 degrees about 36,000 yards (32,920 m)
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Mount / Turret Data
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Designation Two-gun Turrets
  "13" (4)
Weight  N/A
Elevation about  -5 / +30 degrees 
Elevation Rate N/A
Train About +150 / -150 degrees
Train Rate N/A
Gun recoil N/A
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Data from
"Naval Weapons of World War Two" by John Campbell
"Japanese Warships of World War II" by A.J. Watts
and
Tony DiGiulian's personal data files
Page History

23 December 2006 - Benchmark
23 June 2012 - Updated to latest template