Diadem-class cruiser

	HMCS Niobe
Class overview
Name	Diadem class
Operators	Royal Navy; Royal Canadian Navy;
Preceded by	Powerful class
Succeeded by	Cressy class
Built	1896–1903
In commission	1898–1925
Completed	8
Retired	8
General characteristics
Type	Protected cruiser
Displacement	11,000 tons
Length	435 ft (132.6 m); (462 ft 6 in (140.97 m) o/a);
Beam	69 ft (21.0 m)
Draught	25 ft 6 in (7.77 m); 27 ft 6 in (8.38 m);
Propulsion	2 shaft triple expansion engines:; 16,500 hp (12,300 kW); (Ariadne, Spartiate, Amphitrite and Argonaut: 18,000 hp (13,000 kW)); Belleville boilers;
Speed	20.25 knots (37.50 km/h; 23.30 mph); (Ariadne, Spartiate, Amphitrite and Argonaut: 20.75 knots (38.43 km/h; 23.88 mph));
Range	2,000 nmi (3,700 km; 2,300 mi) at 19 knots (35.2 km/h; 21.9 mph); (bunker capacity 1900 tons);
Complement	677
Armament	16 × single QF 6-inch (152 mm) guns; 14 × single 12-pounder (76 mm) QF guns; 3 × single QF 3-pounder (47 mm) guns; 2 × 18-inch (450 mm) torpedo tubes (underwater); 8 Maxim machine guns;
Armour	Casemates and gun shields 4.5 in (110 mm); Hoists 2 in (51 mm); Deck 4–2.5 in (102–64 mm); Conning tower 12 in (300 mm) fore ; 6 in (150 mm) tube to fore conning tower; 2 in (51 mm) aft conning tower; Armour was Harvey Nickel steel, except for armoured deck.;

The Diadem-class cruiser was a class of "first class" protected cruiser built for the Royal Navy during the 1890s that served in the First World War. The class consisted of eight ships, built at a cost of around £600,000 each.

They were considered "good sea boats" but criticised for their lack of a heavy calibre main armament, bulky unprotected sides, average speed and lack of manoeuvrability despite being considered large ships when completed. They were the last British first class protected cruisers; the armoured cruiser taking the large cruiser role in future."

Class overview
HMCS Niobe
Name	Diadem class
Operators	Royal Navy Royal Canadian Navy
Preceded by	Powerful class
Succeeded by	Cressy class
Built	1896–1903
In commission	1898–1925
Completed	8
Retired	8
General characteristics
Type	Protected cruiser
Displacement	11,000 tons
Length	435 ft (132.6 m) (462 ft 6 in (140.97 m) o/a)
Beam	69 ft (21.0 m)
Draught	25 ft 6 in (7.77 m) 27 ft 6 in (8.38 m)
Propulsion	2 shaft triple expansion engines: 16,500 hp (12,300 kW) (Ariadne, Spartiate, Amphitrite and Argonaut: 18,000 hp (13,000 kW)) Belleville boilers
Speed	20.25 knots (37.50 km/h; 23.30 mph) (Ariadne, Spartiate, Amphitrite and Argonaut: 20.75 knots (38.43 km/h; 23.88 mph))
Range	2,000 nmi (3,700 km; 2,300 mi) at 19 knots (35.2 km/h; 21.9 mph) (bunker capacity 1900 tons)
Complement	677
Armament	16 × single QF 6-inch (152 mm) guns 14 × single 12-pounder (76 mm) QF guns 3 × single QF 3-pounder (47 mm) guns 2 × 18-inch (450 mm) torpedo tubes (underwater) 8 Maxim machine guns
Armour	Casemates and gun shields 4.5 in (110 mm) Hoists 2 in (51 mm) Deck 4–2.5 in (102–64 mm) Conning tower 12 in (300 mm) fore 6 in (150 mm) tube to fore conning tower 2 in (51 mm) aft conning tower Armour was Harvey Nickel steel, except for armoured deck.