The 3rd Year Type was used as an AA gun on most battleships and battlecruisers completed between 1914 and 1925. This was a built-up construction gun similar to the 8 cm/40 Type 41 but used a sliding breech block that was angled at 45 degrees to the right. The 11th Year Type and Type 88 used monobloc barrels with horizontal sliding breech blocks.
The 3rd Year Type and the 11th Year Type were used on many smaller ships and cruisers built prior to World War II. The Type 88 was a "wet gun" used on submarines of the RO 33 and RO 35 classes.
All guns were redesignated in centimeters on 5 October 1917.
Although the Japanese designation was "8 cm," the actual bore diameter of all these weapons was 7.62 cm (3.0").
| Designation | 3"/40 (7.62 cm) 3rd Year Type (Model 1914)
8 cm/40 (3") 3rd Year Type (Model 1914) 8 cm/40 (3") 11th Year Type (Model 1922) 8 cm/40 (3") Type 88 (Model 1928) |
|---|---|
| Ship Class Used On | Capital ships and small cruisers
Auxiliary warships and submarines |
| Date Of Design | 1914, 1922 and 1928 |
| Date In Service | 1916, 1926 and 1932 |
| Gun Weight | 1,323 lbs. (600 kg) |
| Gun Length oa | 126.1 in. (3.203 m) |
| Bore Length | 120.0 in (3.048 m) |
| Rifling Length | All except Model Type IV: 102.7 in. (2.608 m)
Model Type IV: 103.2 in (2.623 m) 1 |
| Grooves | Barrel Model Types I and II: (16) 0.39 in deep x 0.366 in (1.00 mm x 9.300 mm)
Barrel Model Types III, IV and VII: (24) 0.39 in deep x 0.232 in (1.00 mm x 5.905 mm) |
| Lands | 0.160 in (4.07 mm) |
| Twist | Uniform RH 1 in 28 |
| Chamber Volume | 128 in3 (2.1 dm3) |
| Rate Of Fire | 13 to 20 rounds per minute |
- ^The Model Type IV barrel had a slightly longer chamber length, hence the difference in rifling length. The Chamber Volume was the same as in the other Model Types.
| Type | Fixed |
|---|---|
| Weight of Complete Round | Common Type 0 HE: 20.4 lbs. (9.25 kg)
ASW 1a: N/A |
| Projectile Types and Weights | Common Type 0 HE: 13.2 lbs. (5.99 kg)
ASW: 11.7 lbs. (5.3 kg) |
| Bursting Charge | Common Type 0 HE: 1.06 lbs (0.48 kg)
ASW: 1.5 lbs. (0.67 kg) |
| Projectile Length | Common Type 0 HE: 11.1 in (28.2 cm)
ASW: 11.3 in (28.5 cm) |
| Propellant Charge | Common Type 0: 2.0 lbs. (0.9 kg) 20 C3
ASW: N/A |
| Muzzle Velocity | Common: 2,231 to 2,247 fps (680 to 685 mps)
ASW: 820 fps (250 mps) |
| Working Pressure | 14.5 tons/in2 (2,250 kg/cm2) |
| Approximate Barrel Life | 1,200 - 2,000 rounds |
| Ammunition stowage per gun | N/A |
- ^The flat-nosed ASW projectile was issued in 1943 following extensive testing. This is listed in US Naval Technical Mission to Japan report O-19 as being able to penetrate a 4.53 in (11.5 cm) plate of Ducol Steel (roughly equivalent to USN HTS) at a depth of 26 feet (8 meters). However, based upon other errors in this document, I would believe this to be an error in metric to English unit conversion and that the actual performance would more likely be 0.453 in (1.15 cm). Range for this performance is not given.
| Elevation | Range |
|---|---|
| 45 degrees | 11,800 yards (10,800 m) |
| AA Ceiling @ 75 degrees | 23,600 feet (7,200 m) |
| Elevation | Range |
|---|---|
| 40 degrees | 3,500 yards (3,200 m) |
Minimum range of ASW shell is given as 766 yards (700 m). Ranges less than this tended to ricochet.
| Designation | Mountings were all simple pedestal types
Battleships 1b Cruisers
Submarines
|
|---|---|
| Weight | about 3.3 tons (3.35 mt) |
| Elevation | -7 / +75 degrees |
| Elevation Rate | Manually operated, only
7 - 10 degrees per second |
| Train | 360 degrees |
| Train Rate | Manually operated, only
10 - 11 degrees per second |
| Gun recoil | N/A |
- ^All of these guns were removed from the battleships during their 1930s rebuilds and replaced with 12.7 cm/40 Type 89 and 25 mm AA guns.
"Naval Weapons of World War Two" by John Campbell
"Cruisers of World War Two" by M.J. Whitley
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US Naval Technical Mission to Japan report O-19: Japanese Projectiles General Types
US Naval Technical Mission to Japan report O-54(N): Japanese Naval Guns
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Special help from Larry Sawh
23 November 2006 - Benchmark
27 May 2012 - Updated to latest template
15 July 2015 - Noted use on capital ships and cruisers
15 January 2021 - Converted to HTML 5 format
27 January 2022 - Added construction details
24 April 2023 - Added to caption of museum gun and added photograph of firing drill
28 September 2023 - Minor changes to Description for clarity