Lyon Class Battleship - Design - Characteristics

Characteristics

The ships would have been 190 m (620 ft) long between perpendiculars and 194.5 m (638 ft) long overall. They would have had a beam of 29 m (95 ft) and a draft of 8.65 to 9.2 m (28.4 to 30 ft). Their full load displacement was estimated at 29,000 t (29,000 long tons; 32,000 short tons). The propulsion system had not been settled by the time the class was cancelled; the design staff proposed either the mixed steam turbine and triple expansion engine system used in the first four ships of the preceding Normandie class or the all-turbine system used in the last ship of the previous class, Béarn. They also considered new geared turbines that had proved satisfactory in the new destroyer Enseigne Gabolde. The final design called for a propulsion system rated at 43,000 shaft horsepower (32,000 kW) with a top speed of 23 knots (43 km/h; 26 mph). An unknown number of boilers were trunked into two funnels amidships.

Sixteen 340mm/45 Modèle 1912 guns mounted in four quadruple turrets comprised the main battery. The turrets, which were equipped with electric-hydraulic training and elevation gear, were all mounted on the centerline, though the arrangement is not clear. According to Conway's All the World's Fighting Ships, one turret was placed forward, one amidships, and two in a superfiring pair aft. The contemporary Journal of United States Artillery, however, suggests the turrets would have been mounted in two superfiring pairs, forward and aft. The turrets weighed 1,500 t (1,500 long tons; 1,700 short tons), and were electrically trained and hydraulically elevated. The guns were divided into pairs and mounted in twin cradles; a 40 mm (1.6 in) thick bulkhead divided the turrets. Each pair of guns had its own ammunition hoist and magazine. They could be fired simultaneously or independently. The guns had a range of 16,000 m (52,000 ft) and had a rate of fire of two rounds per minute. The shells were 540-kilogram (1,200 lb) armor-piercing rounds and were fired with a muzzle velocity of 800 meters per second (2,600 ft/s).

The secondary battery was to consist of twenty-four guns, either the 138.6 mm /55 Modèle 1910 or a new automatic model, each singly-mounted in casemates in the hull. The M1910 guns fired a 36.5 kg (80 lb) shell at a muzzle velocity of 830 m/s (2,700 ft/s). The ships would also have been equipped with an unknown number of 40 mm (1.6 in) or 47 mm (1.9 in) anti-aircraft guns and six torpedo tubes of unknown size, submerged in the hull. The ships would have been protected with a variation of the armor layout of the previous Normandie class. The primary alterations were slightly thinner casemate armor and upper deck plating to compensate for improved armor below the waterline.