HMS Canopus (1897) - Technical Description

Technical Description

HMS Canopus was laid down at Portsmouth Dockyard on 4 January 1897, launched on 12 October 1897, and completed on 5 December 1899. She was named after the ancient city of Canopus, Egypt, where the Battle of the Nile took place.

Canopus and her five sister ships were designed for service in the Far East, where the new rising power Japan was beginning to build a powerful and dangerous navy. These vesseles were intended to be able to transit the Suez Canal. They were designed to be smaller (by about 2,000 tons), lighter, and faster than their predecessors, the Majestic-class battleships, although they were slightly longer at 430 feet (131 m). In order to save weight, Canopus carried less armour than the Majestics, although the change from Harvey armour in the Majestics to Krupp armour in Canopus meant that the loss in protection was not as great as it might have been, Krupp armour having greater protective value at a given weight than its Harvey equivalent. Still, the armour of the Canopus class was light enough to make them almost second-class battleships. Part of their armour scheme included the use of a special 1-inch (2.54 mm) armoured deck over the belt to defend against plunging fire by howitzers that France reportedly planned to install on its ships, although this report proved to be false.

Canopus had four 12-inch (305-mm) 35-calibre guns mounted in twin turrets fore and aft; these guns were mounted in circular barbettes that allowed all-around loading, although at a fixed elevation. The ships also mounted twelve 6-inch (152-mm) 40-calibre guns (sponson mounting allowing some of them to fire fore and aft) in addition to smaller guns, and four 18-inch (450-mm) submerged torpedo tubes.

The Canopus class ships were the first British battleships with water-tube boilers, which generated more power at less expense in weight compared with the cylindrical boilers used in previous ships. The new boilers led to the adoption of fore-and-aft funnels, rather than the side-by-side funnel arrangement used in many previous British battleships. The Canopus-class ships proved to be good steamers, consuming 10 tons of coal per hour at full speed, with a high speed for battleships of their time, a full two knots faster than the Majestics.