The D'Estrées class comprised two protected cruisers of the French Navy built in the late 1890s. The two ships were and , though a third was projected but was canceled before work began. They were ordered during a period of intense debate in the French fleet between officers who favored large armored cruisers and those who preferred smaller vessels more suited to long-distance cruising abroad. The D'Estrées-class cruisers were intended to operate in the French colonial empire. The ships were armed with a main battery of two guns supported by four guns and they had a top speed of .
D'Estrées and Infernet initially served in the Northern Squadron after entering service in the late 1890s, though they were quickly transferred elsewhere. D'Estrées went to the Atlantic station in 1902, while Infernet had been sent to French Madagascar by 1901. The latter ship then served a stint in the East Indies from 1903 to 1905, thereafter returning to France, where she was lost in an accidental grounding in 1910. D'Estrées was assigned to the 2nd Light Division at the start of World War I in August 1914 before being moved to the Syrian Division, where she took part in operations against Ottoman forces ashore. She patrolled the Red Sea and Indian Ocean from 1916 to the end of the war in 1918. D'Estrées was then sent to East Asia, where she served until being discarded in 1922.
Design
In the 1880s and 1890s, factions in the French Navy's officer corps argued over the types of cruiser that best served France's interests. Some argued for a fleet of small but fast protected cruisers for commerce raiding, another sought larger and more powerful armored cruisers that were useful for patrolling the country's colonial possessions, while another preferred vessels more suited to operations with the home fleet of battleships. In 1896, the (Superior Naval Council) ordered the two cruisers of the D'Estrées class for the construction program that was to begin that year at the behest of the colonialists for use in the French overseas empire. A third member of the class, provisionally designated "K3", was authorized in 1897 but was not built; by that time, the French naval command had decided to build larger armored cruisers for all cruiser tasks, including colonial patrol duties.
Characteristics and machinery
The two ships of the D'Estrées class were long overall, with a beam of and a draft of . They displaced . Their crew numbered 235 officers and enlisted men.
The ships' hulls included a ram bow and an overhanging stern, but unlike other French cruisers of the period, they lacked a double bottom or a longitudinal bulkhead. Below the waterline, they were covered with a layer of wood and copper sheathing to protect them from biofouling on extended voyages overseas, where they would not have reliable access to shipyard facilities. The ships had a flush deck and a minimal superstructure, consisting primarily of a small conning tower. They had three pole masts, though one was later removed from each vessel.
The ships' propulsion system consisted of a pair of vertical triple-expansion steam engines driving two screw propellers. Each engine was placed in its own engine room, divided by a watertight bulkhead to prevent flooding from disabling both engines. Steam was provided by eight coal-burning Normand-type water-tube boilers that were ducted into two widely-spaced funnels. The boilers were divided into pairs in four boiler rooms.
Their machinery was rated to produce for a top speed of . They carried of coal for the boilers, and up to at full load, which gave the ships a cruising radius of up to at a speed of , according to the contemporary Journal of the Royal United Service Institution. Warship International, citing the 1905 Marine Almanac, credits the class with a cruising radius of just at 10 knots.
Armament and armor
The ships were armed with a main battery of two Modèle 1893 45-caliber guns. They were placed in individual pivot mounts with gun shields, one forward and aft on the centerline. They were supplied with a variety of shells, including solid, cast iron projectiles, and explosive armor-piercing (AP) and semi-armor-piercing (SAP) shells, firing with a muzzle velocity of .
The main battery was supported by a secondary battery of four Modèle 1891 guns, which were carried in sponsons in the hull. One pair was placed abreast the conning tower, and the other set of guns was located on either side of the rear funnel. The guns fired cast iron and AP shells with a muzzle velocity of .