French
152 mm/55 (6") Model 1930
Updated 22 July 2007
These were introduced as SP guns on light cruisers and proved to be quite successful in that role.  However, the DP version built for the Richelieu class battleships was too ambitious for its time and was generally conceded to be a failure, with some of the mountings being replaced by smaller AA weapons.

The guns in cruiser mountings were in individual cradles, with training and elevation supplied by electric motor with hydraulic drive and RPC.

The DP mountings for the battleships were designed to load at any angle and were provided with dual-hoist systems, one for surface projectiles and one for AA, so that the weapons could quickly convert between them.  Unfortunately, this system proved to be a source of jamming and the ROF figure, low as it was, could not be maintained.  The low train and elevation rates of these mountings meant that they could not track fast-moving aircraft targets, further degrading their usefulness in the AA role.  In 1939, it was decided to replace some of  Richelieu's DP mounts with 100 mm (3.9") guns in order to improve her mid-range AA capability.

These guns were built with autofretted jacket, breech ring and loose barrel and used a vertical sliding block.

Actual bore size was 15.24 cm (6.0").
WNFR_6-55_m1931_Marseillaise_pic.jpg

Light cruiser Marseillaise in July 1941
Ministère de la Défense Photograph
WNFR_6-55_m1931_Jean_Bart_install_pic.jpg

Installing a 152 mm gun on Jean Bart in August 1947
Ministère de la Défense Photograph
WNFR_6-55_m1931_Jean_Bart_turret_pic.jpg

Installing 152 mm gun on Jean Bart in December 1947
Ministère de la Défense Photograph
WNFR_6-55_m1931_Richelieu_top_pic.jpg

152 mm (6") DP mountings on Richelieu following her US refit
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Gun Characteristics
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Designation 152 mm/55 (6") Model 1930
Ship Class Used On Emile Bertin, La Galissonnière, De Grasse and Richelieu Classes
Date Of Design 1930
Date In Service 1935
Gun Weight 7.657 tons (7.780 mt)
Gun Length oa 348.8 in (8.860 m)
Bore Length 330.3 in (8.390 m)
Rifling Length 282.1 in (7.166 m)
Grooves (46) 0.59 in deep x 0.290 in (1.5 mm x 7.37 mm)
Lands 0.118 in (3.0 mm)
Twist Uniform RH 1 in 25.59
Chamber Volume 1,775 in3 (29.09 dm3)
Rate Of Fire
(see Note)		 Battleships
   AA - 5.0 rounds per minute
   ASu - 6.5 rounds per minute

Cruisers
   5 rounds per minute
Note:  The planned ROF for the battleships was 8 rounds per minute.  The above figures represent the actual wartime experience.  Postwar, modifications were carried out on Richelieu in 1946, 1947 and 1950-51 and on Jean Bart during 1951-55.

Expected ROF after modifications :
   AA - 8.6 rounds per minute
   ASu - 7.5 rounds per minute

Actual ROF:
   Both AA and ASu - about 6.0 rounds per minute
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Ammunition
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Type Separate
Projectile Types and Weights AP - 119.4 lbs. (54.17 kg)
AP O.Pf.K Model 1931 - 123 lbs. (55.83 kg)
HE - (See Note)
US supplied AP - 129.6 lbs. (58.8 kg)
AA - 104 lbs. (47 kg)
Bursting Charge AP - 3.8 lbs. (1.7 kg)
Others - N/A
Projectile Length AP - 28.3 in (71.8 cm)
HE - 28.6 in (72.6 cm)
Propellant Charge 38.1 lbs. (17.3 kg) BM11
Cartridge - 37.7 lbs. (17.1 kg)
Muzzle Velocity 
French 119.4 lbs. (54.17 kg) AP		 2,854 fps (870 mps)
Muzzle Velocity
USN 129.9 lbs. (58.8 kg) AP		 2,756 fps (840 mps) 
Muzzle Velocity
104 lbs. (47 kg) AA		 2,953 fps (900 mps)
Working Pressure 20.3 tons/in2 (3,200 kg/cm2)
Approximate Barrel Life about 700 rounds
Ammunition stowage per gun See Note 5
Notes:

1) As in many French weapons, there were several different kinds of AP and HE shells provided.  These weighed between 119.4 to 126.0 lbs. (54.17 to 57.15 kg).

2) During World War II, the USN provided a modified version of the 130 lbs. (59 kg) 6" (152 mm) Mark 35 AP projectiles for use on Richelieu.

3) It appears that the same cartridge case and propellant charge were used for all French-manufactured AP and HE rounds.

4) Richelieu used yellow dye for these shells.  Jean Bart was to have used orange dye, but this does not appear to have ever been implemented.

5) Ammunition outfits

Richelieu Pre-War
   AP - 978 rounds
   HE - 1,956 rounds
   Illumination - 656 rounds

Jean Bart Post-War
   AP - 750 rounds
   HE - 2,250 rounds
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Range
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Elevation With USN 129.9 lbs. (58.8 kg) AP shell
Range @ 45 degrees 29,480 yards (26,960 m)
Elevation With 119.4 lbs. (54.17 kg) AP Shell
Range @ 45 degrees 28,950 yards (26,474 m)
Elevation With 104 lbs. (47 kg) AA shell
Range @ 45 degrees 26,465 yards (24,200 m)
Ceiling @ 80 degrees about 46,000 feet (14,000 m)
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Armor Penetration with 129.9 lbs. (58.8 kg) AP Shell
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Range
Side Armor
Deck Armor
10,900 yards (9,970 m)
4.8" (122 mm)
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Note:  This data is from "Battleships:  Allied Battleships in World War II" and is apparently based upon the USN Empirical Formula for Armor Penetration.
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Mount / Turret Data
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Designation SP Triple Mount
   All cruisers (3):   Model 1930

DP Triple Mount
   Richelieu (5):  Model 1936
Weight Model 1930:  169.3 tons (172 mt)

Model 1936:  224.4 tons (228 mt)
Elevation Model 1930
   -10 / +45 degrees

Model 1936
   As planned:  -10 / +90 degrees
   As built:  Centerline Turrets:  -8.5 / +75 degrees, Lateral Turrets: -6.5 / +75 degrees
   After World War II:  Centerline Turrets:  -8.5 / +85 degrees, Lateral Turrets: -6.5 / +85 degrees
Rate of Elevation 8 degrees per second
Train Model 1930:  about +150 / -150 degrees

Model 1936
  Lateral Turrets:  +/- 175 degrees
  Centerline Turret:  +/- 150 degrees
Rate of Train 12 degrees per second
Gun Recoil 29.5 in (75 cm)
Loading Angle Model 1930:  -5 to +15 degrees

Model 1936:  See note
Notes:

1) A catapult rammer loaded the projectiles while a chain rammer was used for the cartridges.

2) Model 1936 was intended to load at any angle over the full elevation range of -10 / +90 degrees, but in fact loading was difficult or impossible beyond +45 degrees.  As a result, the maximum elevation was reduced to +75 degrees.  Postwar modifications increased the maximum elevation to +85 degrees.

3) Two of the DP mountings on Richelieu were removed prior to completion.

4) Richelieu had delay coils fitted to the center gun of each mount around 1948 in an effort to reduce dispersion.
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Data from
"Naval Weapons of World War Two" by John Campbell
"Les Cuirassés: Dunkerque, Strasbourg, Richelieu & Jean Bart" by Robert Dumas
"Battleships:  Allied Battleships in World War II" by W.H. Garzke, Jr. and R.O. Dulin, Jr.
"Richelieu" by René Sarnet and Eric Le Vaillant
"Battleships of World War Two" and "Cruisers of World War Two" both by M.J. Whitley
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Ministère de la défense
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Special help by Vincent Perdrix and Matthew Rodchenko