France 100 mm/55 (3.9") Model 1968, CADAM and Model 1968-II

France
100 mm/55 (3.9") Model 1968
100 mm/55 (3.9") Model 1968 CADAM
100 mm/55 (3.9") Model 1968-II
Updated 28 March 2012

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.

100 mm Model 1968 CADAM on Frégate De Grasse (D 612)
The single control cupola can just be seen on the right of the far mounting
Marine Nationale Photograph

100 mm Model 1968-II on Frégate La Fayette (F 710)
The access ladder on the front is removable, giving this mounting a clean look
Marine Nationale Photograph

100 mm Model 1968-II on Frégate Courbet (F 712)
Marine Nationale Photograph

100 mm/55 Model 1968 CADAM on FS Commandant Ducuing (F 795) in foreground
5"/54 Mark 45 Mod 2 on HMAS Warramunga (FFH 152) in background
Photograph taken in October 2006
U.S. Navy Photograph No. 061030-N-5555T-020

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

Ammunition .

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 - 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
Notes: 1) Illumination rounds burn between 30 and 50 seconds at 120,000 candela. 2) These mountings use a 35 round ready-service magazine.

Range
.

Elevation	With 29.8 lbs. (13.5 kg) HE Shell
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 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
Note: 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.

Data from
"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
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Marine Nationale Press Releases and Articles
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Special help by Matthew Rodchenko

Page History

08 November 2008 - Benchmark
28 March 2012 - Updated to latest template