The original Model 1968 was a lighter version of the 100 mm/55 Model 1953 but was capable of fully automatic firing. Later versions added a digital FCS. The Model 1968 mountings can be distinguished from the older mountings by the single local control cupola on the left face.

The Model 1968 CADAM (short for cadence améliorée - "improved firing") - was an enhancement program instituted during the late 1980s. During major refits, some older ships had their Model 1968 mountings removed and replaced with the Model 1968 CADAM.

The Model 1968-II or Model 100 TR (technologie rénovée - "renovated technology") was an enhancement program of the 1990s to improve reliability and operation. The gunhouse for this model is made out of composite materials so as to reduce the radar signature (low RCS). It can be easily distinguished from earlier models by its more angular design and by the lack of hand grips on its front face. As these mountings do not have any provision for local control, they lack the control cupolas of the earlier models.

Gun Characteristics

Designation 100 mm/55 (3.9") Model 1968
100 mm/55 (3.9") Model 1968 CADAM
100 mm/55 (3.9") Model 1968-II
Ship Class Used On Model 1968 and CADAM: Tourville, Georges Leygues, d'Estienne d'Orves, Floréal and Cassard classes Rebuilt Surcouf (T47) class and Colbert
Model 1968-II: La Fayette class
Date Of Design 1968
Date In Service Model 1968: 1971
Model 1968 CADAM: 1986
Model 1968-II: 1996
Gun Weight N/A
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 Model 1968: 60 rounds per minute
Model 1968 CADAM: 78 rounds per minute
Model 1968-II: 78 - 80 rounds per minute


Type Fixed
Weight of Complete Round 51.8 lbs. (23.5 kg)
Projectile Types and Weights OEA F1 HE: 29.8 lbs. (13.5 kg)
OPF F4 PFHE: 29.8 lbs. (13.5 kg)
Illum 1: 29.8 lbs. (13.5 kg)
Bursting Charge HE: 2.4 lbs. (1.1 kg)
PFHE: 2.2 lbs. (1.0 kg) - Shell contains 1,350 high density steel balls of 1 gram each
Projectile Length N/A
Complete round: 42.7 in (108.5 cm)
Propellant Charge 9.9 lbs. (4.5 kg)
Muzzle Velocity New gun: 2,844 fps (867 mps)
Average gun: 2,805 fps (855 mps)
Working Pressure 17.9 tons/in2 (2,825 kg/cm2)
Approximate Barrel Life 3,000 rounds at high rates of fire
6,000 rounds at lower rates of fire
Ammunition stowage per gun about 600 rounds 2
  • ^Illumination rounds burn between 30 and 50 seconds at 120,000 candela.
  • ^These mountings use a 35 round ready-service magazine.


Range with 29.8 lbs. (13.5 kg) HE Shell
Elevation Distance
Maximum Range @ 45 degrees 18,876 yards (17,260 m)
Effective Range 13,120 yards (12,000 m)
AA Ceiling 19,700 feet (6,000 m)

Mount/Turret Data

Designation Single Mount 1a:

Colbert (2), Tourville (2), Georges Leygues (1), d'Estienne d'Orves (1), Floréal (1) and Cassard (1): Model 1968 or Model 1968 CADAM
La Fayette (1): Model 1968-II

Weight 21 tons (22 mt)
Elevation -5 / +80 degrees
Rate of Elevation Model 1968: 25 degrees per second
Model 1968 CADAM and Model 1968-II: 29 degrees per second
Train -150 / +150 degrees
Rate of Train 40 degrees per second
Gun Recoil N/A
  • ^Some Surcouf (T47) and Duperré (T53) class destroyers and the AA cruiser Colbert were rebuilt and rearmed with these guns. For example, Duperré (D633) was originally completed in 1957 with six 127 mm/54 and six 57 mm/60 guns. She was rebuilt in 1980 with a single 100 mm/55 Model 1968 and an Exocet missile battery.

Additional Pictures


"The Naval Institute Guide to World Naval Weapon Systems 1991/1992" by Norman Friedman
"Jane's Ammunition Handbook: Ninth Edition 2000-2001" edited by Terry J. Gander and Charles Q. Cutshaw
"Jane's Fighting Ships: 1998-99" edited by Capt. Richard Sharpe RN
"Defense & Armament Heracles International" Issue #70, February 1988
Marine Nationale Press Releases and Articles
Special help by Matthew Rodchenko

Page History

08 November 2008 - Benchmark
28 March 2012 - Updated to latest template
24 August 2021 - Updated to HTML 5 format and reorganized notes