Japan
5.5"/50 (14 cm) 3rd Year Type
14 cm/50 (5.5") 3rd Year Type
Updated 05 March 2015

This weapon was the standard secondary gun for most of Japan's capital ships built or planned between 1915 and 1922 and was the primary gun on light cruisers built prior to 1930.  It was also the most numerous coastal defense gun used during World War II.

This gun was adopted in 1914 as a replacement for earlier 6" (15.2 cm) guns as it was felt that the lighter shells were better suited for manual handling by the average Japanese crewman.

Redesignated in centimeters on 5 October 1917.

Earlier guns were built with four layers and wire-winding (Model No. II), but later guns were of built-up construction without the wire (Model No. IV).  Used Welin screw breech-blocks.

WNJAP_55-50_3ns_Yubari_pic.jpg

Light Cruiser IJN Yubari in November 1924
This cruiser had single 14 cm (5.5") mounts bow and stern with twin 14 cm (5.5") superfiring mounts above them
U.S. Naval Historical Center Photograph # 19-N-9957

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Click here for additional photographs
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Gun Characteristics
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Designation 5.5"/50 (14 cm) 3rd Year Type (Model 1914)
14 cm/50 (5.5") 3rd Year Type (Model 1914)
Ship Class Used On
(see Note)
Capital Ships:  Ise, Nagato, Amagi, Kaga, Kii and "13" classes
Carrier:  Hôshô
Cruisers:  Tenryû, Kuma, Nagara, Sendai, Yubari and Katori classes
Seaplane Carrier:  Nisshin
Minelayer:  Okinoshima
Submarine Tenders:  Jingei class
Date Of Design 1914
Date In Service about 1916
Gun Weight 5.5 - 5.6 tons (5,600 - 5,700 kg)
Gun Length oa 284.8 in (7.235 m)
Bore Length 275.6 in (7.000 m)
Rifling Length 235.0 in (5.968 m)
Grooves (42) 0.55 in deep x 0.252 in (1.40 mm x 6.40 mm)
Lands 0.160 in (4.07 mm)
Twist Uniform RH 1 in 28
Chamber Volume 1,404 in3 (23 dm3)
Rate Of Fire 6 to 10 rounds per minute, depending upon the rate of supply
Note:  Many of the capital ships listed above were cancelled, scrapped or converted to aircraft carriers as a result of the Washington Naval Limitation Treaty.  As a result, only the Ise and Nagato classes saw service with this weapon.  This scrapping did free up many guns for use in coastal batteries, as mentioned above.
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Ammunition
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Type Bag
Projectile Types and Weights
(see Note 1)
Capped Common - 83.8 lbs. (38.0 kg)
Capped Common Mods 1 & 2 - 83.8 lbs. (38.0 kg)
Common Type 0 HE - 83.8 lbs. (38.0 kg)
Common Type 2 HE - 83.8 lbs. (38.0 kg)
ASW - 92.4 lbs. (42.0 kg)
Common Type 3 IS - 83.8 lbs. (38.0 kg)
Bursting Charge Capped Common - 4.4 lbs. (2.0 kg)
Capped Common Mods 1 & 2 - 4.4 lbs. (2.0 kg)
Common Type 0 - 6.3 lbs. (2.86 kg)
Common Type 2 - 5.7 lbs. (2.60 kg)
ASW - 6.3 lbs. (2.86 kg)
Projectile Length Capped Common Mods 1 & 2 - 21.65 in (55.0 cm)
Common Type 0 - 21.81 in (55.4 cm)
Common Type 2 - 21.81 in (55.4 cm)
ASW - 22.56 in (57.3 cm)

Others - N/A

Propellant Charge All except ASW
   22.8 lbs. (10.33 kg) 40C or 50C
   24.2 lbs. (10.97 kg) 37DC

ASW - N/A

Muzzle Velocity All except ASW - 2,789 to 2,805 fps (850 to 855 mps)
ASW - 820 fps (250 mps)
Working Pressure 18.4 to 18.5 tons/in2 (2,900 to 2,910 kg/cm2)
Approximate Barrel Life 500 - 600 Rounds
Ammunition stowage per gun N/A
Notes:

1) Capped Common shells were introduced in 1916 and were replaced by Capped Common Mods 1 & 2 in 1934.  Common Type 4 was introduced in 1932 and was replaced by Common Type 0 in 1940.

2) IS is my abbreviation for the Type 3 Common incendiary shrapnel round (sankaidan) intended for AA use.

3) The ASW projectile was flat nosed.  ASW rounds were issued in 1943 following extensive testing.  Penetration performance not available.

4) The propellant charge was in one bag with a 2.1 oz (60 gm) black powder igniter.

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Range
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Elevation With 83.8 lbs. (38.0 kg) HE Shell
Range @ 20 degrees 17,280 yards (15,800 m)
Range @ 25 degrees 19,140 yards (17,500 m)
Range @ 30 degrees 20,890 yards (19,100 m)
Range @ 35 degrees 22,500 yards (20,574 m)
Elevation With 92.4 lbs. (42.0 kg) ASW Shell
Range @ 40 degrees 4,590 yards (4,200 m)
Note:  Minimum range of ASW shell is given as 875 yards (800 m).  Ranges less than this tended to ricochet.
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Mount / Turret Data
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Designation Single casemate mounts
   Ise (20), Nagato (20), Kaga (20), Kii (16-20) and Amagi (16):  N/A

Single pedestal mounts
   Hôshô (4), Tenryû (4), Kuma (7), Nagara (7), Naka (7) and Yubari (2):  N/A

Twin Mounts
   Yubari (2), Okinoshima (2) and Jingei (2) Classes:  A
   Katori (2) and Nisshin (3):  A2

Weight
(see Note 2)
Single Mounts:  About 20 tons (21 mt)

Twin Mounts:  About 49 tons (50 mt)

Elevation
(see Note 3)
Single Mounts

   Ise class:  As built:  -7 / +20 degrees.  Later:  -7 / +30 degrees
   Nagato class:  As built:  -7 / +25.  Later:  -7 / +35 degrees
   Tenryû class:  -7 / +20 degrees
   Kuma and Nagara classes:  -7 / +25 degrees
   Sendai and Yûbari classes:  -7 / +30 degrees

Twin Mounts
   Yubari, Jingei and Okinoshima:  -5 / +30 degrees
   Katori class and Nisshin:  -5 / +35 degrees

Elevation Rate Single Mounts:  8 degrees per second - Manual operation, only

Twin Mounts:  6 degrees per second

Train Capital Ships:  About +70 / -70 

Light Cruisers:  +150 / -150 degrees

Train Rate Single Mounts:  8 degrees per second - Manual operation, only

Twin Mounts:  4 degrees per second

Gun recoil N/A
Loading Angle Any angle up to +20 degrees (hand ramming)
Notes:

1) Single mountings on cruisers had bucket chain hoists which brought both projectiles and propellant up to the weather deck.  All transfers to and from the magazines, hoists and guns were performed manually.  Single mounts were entirely hand worked while twin mounts were provided with electro-hydraulic training gear.

2) "Naval Weapons of World War Two" says that the twin mounts on the Katori class weighed 48 tons (49 mt) while the twin mountings on the other ships were 35.9 to 36.9 tons (36.5 to 37.5 mt).  This data appears to be sourced from US Naval Technical Mission to Japan report O-47(N1).  Campbell credits this weight difference to the Katori class having thick 5 cm (2 inch) shields versus 1 cm (0.4 inch) shields on the other ships, although shield thickness is not noted in O-47(N1).  However, this weight difference and level of protection is not supported by "Japanese Cruisers of the Pacific War," which states that all ships had a 1 cm (0.4 inch) shield and weighed 49 tons (50 mt).  This weight seems consistent with the single mounting at 20 tons (21 mt) as reported in this same source, as the single mounting was an open back type while the twin was a fully enclosed design.  I also find it difficult to believe that the Katori class would have had such a thick gun shield as they were designed and built as training cruisers.  These ships lacked all but splinter protection everywhere else, as thicker armor would have taken weight away from their primary purpose of training.  For these reasons, I believe that "Japanese Cruisers of the Pacific War" is probably the correct source to use for these mountings.

3) Some cruiser mounts were restricted to a minimum elevation of -5 degrees depending upon location.  Gun elevation for the Ise class was increased during modernization in 1935 and four guns were removed.  Gun elevation for the Nagato class was increased during modernization in 1934 and two guns were removed.

4) The A Twin Mounting served as a model for those for the 12.7 cm/50 (5") guns used on the "Special" destroyers of the Fubuki class.

5) Yubari had both single guns removed during a refit in 1943-44.  The bow gun was replaced by a 12 cm/45 (4.7") Type 10 gun while the after gun was replaced by a triple 25 mm Type 96.

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Data from
"Naval Weapons of World War Two" by John Campbell
"Japanese Cruisers of the Pacific War" by Eric Lacroix and Linton Wells II
"The Imperial Japanese Navy in the Pacific War" by Mark E. Stille
"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-47(N1):  Japanese Naval Guns and Mounts, Article 1 - Mounts under 18"
US Naval Technical Mission to Japan report O-54(N):  Japanese Naval Guns
Page History

23 August 2007 - Benchmark
23 September 2010 - Added notes regarding elevation and weight of twin mounts
05 March 2015 - Added notes regarding removal of guns during refits