Topaze class cruiser
Encyclopedia
The Topaze-class (or "Gem-class") cruisers were a class of third-class protected cruisers. They were the last class of protected cruiser built for the Royal Navy. Four ships were built and a further 4 ships of the class were canceled before their keels were laid.
s, making her the first ship larger than a destroyer to be so fitted. She developed 12,000 ihp and was capable of 23 knots, and although her maximum range at 10 knots was reduced, she benefited from greater efficiency at high speed, and compared to her sisters, she was able to travel 1,000 nautical miles further at 20 knots.
Propulsion
Sapphire, Topaze and Diamond were fitted with steam reciprocating engines and twin shafts developing about 10000 ihp, and generating a top speed of about 22 knots (43.1 km/h). Amethyst was fitted with steam turbineSteam turbine
A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. Its modern manifestation was invented by Sir Charles Parsons in 1884....
s, making her the first ship larger than a destroyer to be so fitted. She developed 12,000 ihp and was capable of 23 knots, and although her maximum range at 10 knots was reduced, she benefited from greater efficiency at high speed, and compared to her sisters, she was able to travel 1,000 nautical miles further at 20 knots.