Powerful-class cruiser

HMS Powerful in Sydney harbour.
Class overview
Name:	Powerful class
Operators:	Royal Navy
Preceded by:	Edgar class
Succeeded by:	Diadem class
Built:	1894–98
In service:	1897–1932
Completed:	2
Scrapped:	2
General characteristics
Type:	Protected cruiser
Displacement:	14,200 long tons (14,400 t) (deep load)
Length:	500 ft (152.4 m) (p/p) 538 ft (164.0 m) (o/a)
Beam:	71 ft (21.6 m)
Draught:	27 ft (8.2 m)
Installed power:	25,000 shp (18,600 kW)
Propulsion:	2 shafts 2 vertical triple-expansion steam engines 48 Belleville water-tube boilers
Speed:	22 knots (40.7 km/h; 25.3 mph)
Range:	7,000 nmi (12,960 km; 8,060 mi) at 14 knots (25.9 km/h; 16.1 mph)
Complement:	894
Armament:	2 × BL Mk VIII guns 12 × QF 6-inch (152 mm) guns 16 × 12-pdr (3-inch, 76 mm) guns 12 × 3-pdr (47 mm) guns 4 submerged torpedo tubes
Armour:	Deck: 2–6 in (51–152 mm) Barbettes: 6 in (152 mm)

The Powerful class were first-class protected cruisers built for the Royal Navy in the 1890s. There were two ships in the Powerful class, the lead ship, Powerful, and Terrible.

Design

File:Powerful class cruiser diagram Brasseys 1897.jpg

Right elevation, deck plan and armament layout as depicted in Brassey's Naval Annual 1897

They were designed for hunting down commerce raiders such as the Russian armoured cruiser Rurik and numerous French armoured cruisers of the era. As a result, these were very large cruisers intended to be able to dominate other cruisers in a one-on-one battle. A secondary function was to act as a high speed, long range transport (which in fact was their only actual use during war).

The original armament was to be a uniform battery of twenty 6-inch guns. However, the Director of Naval Ordnance strongly believed that fewer larger (8-inch) guns would produce a better ship. The Office of Naval Construction countered that a 6-inch gun was suitable for fighting other cruisers, and that the 8-inch gun was too slow-firing to fight cruisers yet too small to fight battleships. He asked for at least a few guns of at least 9.2 inches as the smallest capable of damaging a contemporary battleship. This argument won, and the armament as constructed became two 9.2-inch guns and twelve 6-inch guns. Observers criticized these ships for their apparently light armament given their size. However, they had excellent sea keeping, high speed, and long range, all of which required space and tonnage.

These were the first cruisers in the Royal Navy with four funnels.

These ships had an armoured deck to stop plunging shells. This deck curved, with its crown in the middle of the ship 3 feet 6 inches (1.07 m) above the waterline, and the edges were 6 feet 6 inches (1.98 m) below the waterline. The deck was 6 inches (150 mm) thick over the machinery, 4 inches (100 mm) thick over the magazines, and 2.5 inches (64 mm) thick in the middle of the ship.

The dimensions of this class were limited by the then available dockyards available to build and maintain them.

In comparison to the Edgar class, these ships had a crew 64% larger, cost 61% more to build, had more than twice the horsepower, had 660 tons of armour versus 340 tons, were two knots faster, but had very nearly the same armament. The Edgar class remained to fight during the First World War, but the Powerful class had left the active fleet by then.

Building Programme

The following table gives the build details and purchase cost of the members of the Powerful class. Standard British practice at that time was for these costs to exclude armament and stores.

Ship	Builder	Date of			Cost according to
		Laid Down	Launch	Completion	(BNA 1904)	(BNA 1906)
Powerful	Vickers, Barrow in Furness	1894	24 July 1895	8 June 1897	£741,870	£705,335
Terrible	J&G Thompson, Clydebank	1894	27 May 1895	24 March 1898	£740,584	£708,619

Trials

Ship	Date	4 hours forced draught		30 hours natural draught		Source
Powerful	1896	25,866 ihp	21.8 kn (40.4 km/h) bad weather	18,433 ihp	20.6 kn (38.2 km/h)	Janes 1900
Terrible	1897	25,572 ihp	22.4 kn (41.5 km/h)	18,493 ihp	20.96 kn (38.82 km/h)	Janes 1900

Terrible 1898 Trials

• 60 hours at 1/5 power (20 boilers) 5084 ihp = 12.8 kn (23.7 km/h)
• 68 hours at 2/5 power 10,246 ihp = 17 kn (31 km/h)
• 60 hours at 3/5 power 15,554 ihp = 19.6 kn (36.3 km/h)
• 60 hours at 3/4 power 18,515 ihp = 20.3 kn (37.6 km/h)
• 8 hours (22,000 ihp nominal) = 23,053 ihp = 20.7 kn (38.3 km/h)
• 4 hours at full power = 25,513 ihp = 21.9 kn (40.6 km/h)

December 1898 sea trip, Portsmouth to Gibraltar, 12,500 ihp = 18 kn (33 km/h) average. Gibraltar to Malta, average 21.5 kn (39.8 km/h).

Careers

Both ships served in the China Station and provided landing parties which fought in the relief of the Siege of Ladysmith in the Second Boer War in South Africa. This event inspired the Field gun competition. Crews from the two ships also took part in suppressing the Boxer Rebellion in China. After 1904 they were laid up as an economy measure. During the First World War, they had most of their armament removed and served as troop transports and later accommodation ships.

References

• Brassey's Naval Annual 1904
• Brassey's Naval Annual 1906