Design_and_description French_ironclad_Marengo

1 design , description

1.1 propulsion
1.2 armament
1.3 armor

design , description

the océan-class ironclads designed henri dupuy de lôme improved version of provence-class ironclads. ships central battery ironclads armament concentrated amidships. first time in french ironclad 3 watertight iron bulkheads fitted in hull. ironclads of era equipped metal-reinforced ram.

the ship measured 87.73 meters (287 ft 10 in) overall, beam of 17.52 meters (57 ft 6 in). marengo had maximum draft of 9.09 meters (29 ft 10 in) , displaced 7,749 metric tons (7,627 long tons). crew numbered between 750 , 778 officers , men. metacentric height of ship low, between 1.7–2.2 feet (0.5–0.7 m).

propulsion

the océan-class ships had 1 horizontal return connecting rod compound steam engine driving single propeller. engines powered 8 oval boilers. on sea trials engine produced 3,600 indicated horsepower (2,700 kw) , marego reached 13.5 knots (25.0 km/h; 15.5 mph). carried 650 metric tons (640 long tons) of coal allowed steam approximately 3,000 nautical miles (5,600 km; 3,500 mi) @ speed of 10 knots (19 km/h; 12 mph). océan-class ships barque or barquentine-rigged 3 masts , had sail area around 2,000 square meters (22,000 sq ft).

armament

these ships had main armament mounted in 4 barbettes on upper deck, 1 gun @ each corner of battery, remaining guns on battery deck below barbettes. marengo s armament upgraded, before commissioned, 4 274-millimeter (10.8 in) guns in barbettes, , on battery deck, 4 240-millimeter (9.4 in) , 7 138-millimeter (5.4 in) guns. 1885 2 more 274-millimeter guns had been added , of 138-millimeter guns replaced 4 120-millimeter (4.7 in) guns.

the 18-caliber 274-millimeter modéle 1870 gun fired armor-piercing, 476.2-pound (216.0 kg) shell while gun weighed 22.84 long tons (23.21 t). gun fired shell @ muzzle velocity of 1,424 ft/s (434 m/s) , credited ability penetrate nominal 14.3 inches (360 mm) of wrought iron armour @ muzzle. armor-piercing shell of 19-caliber 240-millmeter modele 1870 gun weighed 317.5 pounds (144.0 kg) while gun weighed 15.41 long tons (15.66 t). had muzzle velocity of 1,624 ft/s (495 m/s) , credited ability penetrate nominal 14.4 inches (366 mm) of wrought iron armour @ muzzle. 138-millimeter gun 21 calibers long , weighed 2.63 long tons (2.67 t). fired 61.7-pound (28.0 kg) explosive shell had muzzle velocity of 1,529 ft/s (466 m/s). guns fire both solid shot , explosive shells.

at point ship received dozen 37-millimeter (1.5 in) hotchkiss 5-barrel revolving guns. fired shell weighing 500 g (1.1 lb) @ muzzle velocity of 610 m/s (2,000 ft/s) range of 3,200 meters (3,500 yd). had rate of fire of 30 rounds per minute. hull not recessed enable of guns on battery deck fire forward or aft. however, guns mounted in barbettes sponsoned out on sides of hull did have ability fire fore , aft. late in ship s career 4 above-water 356-millimeter (14.0 in) torpedo tubes added.

armor

the ocean-class ships had complete 178–203-millimeter (7.0–8.0 in) wrought iron waterline belt. sides of battery armored 160 millimeters (6.3 in) of wrought iron. barbette armor 150 millimeters (5.9 in) thick. unarmored portions of sides protected 15-millimeter (0.6 in) iron plates. gardiner says barbette armor later removed improve stability, not confirmed other source.