France
100 mm/55 (3.9") Model 1945
Updated 29 November 2009
Post-war design used as AA on the Richelieu class battleships.  These mountings were radar-controlled and had improved shell-handling capabilities compared to the pre-war 100 mm (3.9") Model 1930.

Barrel was an autofretted monobloc type with a semi-automatic sliding wedge breech mechanism.
WNFR_39-55_m1945_Jean_Bart_pic.jpg

At left can be seen the three forward twin 100/55 mm mountings as they appeared in 1953
At right is a twin 57 mm/60 AA mounting
ECPA(D), Ft. d'Ivry Photograph
WNFR_39-55_m1945_Jean_Bart_aft_pic.jpg

Overhead view of after 100 mm/55 mountings on Jean Bart in 1956
In the foreground is a twin 57 mm/60 AA mounting
Henri Landais Collection Photograph
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Gun Characteristics
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Designation 100 mm/55 (3.9") Model 1945
Ship Class Used On Richelieu Class
Date Of Design 1945
Date In Service 1948
Gun Weight 4,056 lbs. (1,840 kg) including breech
Gun Length oa N/A
Bore Length 216.5 in (5.500 m)
Rifling Length N/A
Grooves N/A
Lands N/A
Twist N/A
Chamber Volume N/A
Rate Of Fire 20 - 25 rounds per minute
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Ammunition
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Type Fixed
Weight of Complete Round 50.5 lbs. (22.9 kg)
Projectile Types and Weights HE Model 1945 - 29.36 (13.32 kg)
HE Model 1951 - 29.36 (13.32 kg)
Bursting Charge N/A
Projectile Length N/A
Complete round - 42.8 in (108.8 cm)
Cartridge Case 100 X 1,145 mm (light alloy)
Propellant Charge 8.84 lbs. (4.01 kg) BM7
Muzzle Velocity 2,805 fps (855 mps)
Working Pressure 17.8 tons/in² (2,800 kg/cm²)
Approximate Barrel Life N/A
Ammunition stowage per gun
(see Note 2)		 1,000 rounds
Notes:

1) HE rounds used German Zt Z S/30 mechanical time fuzes, later versions had a very sensitive nose fuze.  The Model 1951 was intended for night firings.

2) Outfit for Jean Bart in January 1957 consisted of 8,906 HE rounds (day), 3,000 HE rounds (night) and 600 Starshells.

3) Actual French Designations
      HE - OEA Mle 1945 (day)
      HE - OEA Mle 1951 (night)
      Starshell - OEcl Mle 1945
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Range
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Elevation With 29.36 lbs. (13.32 kg) HE Shell
Range @ 40 degrees 18,590 yards (17,000 m)
Range @ 45 degrees 18,880 yards (17,260 m)
AA Ceiling about 37,070 feet (11,300 m) max
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Mount / Turret Data
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Designation Twin Mount
  Jean Bart (12):  CAD Model 1945
Weight 58,532 lbs. (26,550 kg)
Elevation -8 / +70 degrees
Rate of Elevation N/A
Train -90 / +90 degrees
Rate of Train N/A
Gun Recoil N/A
Loading Angle Any
Note:  These mountings were controlled by four gyro-stabilised directors that were patterned after German designs.  Train and elevation were controlled via a Ward Léonard RPC system and there were also semi-automatic and manual backup systems.
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Data from
"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.
"French Battleships:  1922 - 1956" by John Jordan and Robert Dumas
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Special help by Matthew Rodchenko
Page History

21 May 2006 - Benchmark
29 November 2009 - Added photographs and information on projectiles