Alarm-class torpedo gunboat

The Alarm-class torpedo gunboat was the penultimate class of torpedo gunboat built for the Royal Navy. The class was contemporary with the early torpedo boat destroyers, which were faster and thus better suited to pursuit of enemy torpedo boats. By World War I the class had either been sold, converted to submarine depot ships or minesweepers, or reduced to harbour service. Three of the class were lost during World War I while serving in the minesweeping role.

Jason
Class overview
NameAlarm-class torpedo gunboat
Builders
  • Naval Construction & Armament, Barrow
  • Laird Brothers, Birkenhead
  • Devonport Dockyard
  • Sheerness Dockyard
  • Thornycroft, Chiswick
Operators Royal Navy
Preceded bySharpshooter-class torpedo gunboat
Succeeded byDryad-class torpedo gunboat
Built1892–1893
In commission1893–1924
Completed11
Lost3
Scrapped8
General characteristics
TypeTorpedo gunboat
Displacement810 tons
Length242 ft (74 m)
Beam27 ft (8.2 m)
Draught12 ft 6 in (3.81 m) maximum
Installed power
  • 3,500 ihp (2,600 kW)
  • (except Speedy - 5,000ihp)
Propulsion
  • Twin 3-cylinder vertical triple-expansion steam engines
  • Locomotive boilers
  • Twin screws
  • (except Speedy - water-tube boilers)
Speed18.7 kn (34.6 km/h)
Complement91
Armament

Design

The Alarm class was designed by Sir William White in 1889 as an enlarged version of his previous Sharpshooter class. They had a length overall of 242 ft (74 m), a beam of 27 ft (8.2 m) and a displacement of 810 tons. They were engined with two sets of vertical triple-expansion steam engines, two locomotive boilers, and twin screws. This layout produced 3,500 indicated horsepower (2,600 kW), giving them a speed of 18.7 knots (34.6 km/h; 21.5 mph) with forced draught. They carried between 100 and 160 tons of coal and were manned by 91 sailors and officers.

Thornycroft Special - HMS Speedy

While officially classed with the Alarm class, the Speedy was actually a separate design. The Naval Defence Act of 1889 authorised the purchase of an Alarm-class torpedo gunboat built to a design by John I. Thornycroft & Company and built in their yard at Chiswick. Speedy was a three-funnelled vessel (compared to the two-funnelled Admiralty design), but the key difference was the use of water-tube boilers instead of locomotive-type boilers; she produced at least 5,000 indicated horsepower (3,700 kW) and could make 20.5 knots (38.0 km/h; 23.6 mph). The use of water-tube boilers was a key feature of the new torpedo boat destroyers that would make torpedo gunboats (including the Alarm class) obsolete.

Speedy being launched at Chiswick, 18 May 1893

Armament

At build the class was fitted with two QF 4.7-inch (12 cm)/45-pounder guns, four 3-pounder guns and one Gardner machine gun. Five 14-inch (360 mm) torpedo tubes were fitted in the first five vessels, but this was changed to three 18-inch (450mm) torpedo tubes in the rest of the class. They were arranged as a pair of revolving deck mounts, a pair of fixed deck mounts (deleted in the later vessels) and a single bow-mounted tube; three reloads were provided.

Ships
Niger
Speedy
NameShip BuilderLaid downLaunchedCompletedFate
JasonNaval Construction & Armament, Barrow7 September 189114 May 1892June 1893Became a minesweeper in 1909. Sunk by a mine off the west coast of Scotland on 7 April 1917
CirceSheerness Dockyard11 January 189014 June 1892May 1893Became a minesweeper in 1909. Sold for breaking on 30 July 1920
HebeSheerness Dockyard11 January 189015 June 18929 October 1894Became a minesweeper in 1909. Became a depot ship for submarines in 1910 (guns retained). Sold for breaking on 22 October 1919
OnyxLaird Brothers, Birkenhead8 October 18917 September 1892January 1894Became a depot ship for submarines in 1907 (armament removed). Renamed Vulcan II in June 1919 (or April 1920?). Sold for breaking in August 1924 and resold on 9 October 1924
LedaSheerness Dockyard25 June 189113 September 1892November 1893Became a minesweeper in 1909. Sold for breaking on 14 July 1920 and broken up in Germany in 1922
AlarmSheerness Dockyard25 June 189113 September 1892March 1894Sold for breaking on 9 April 1907
JaseurNaval Construction & Armament, Barrow14 September 189124 September 1892July 1893Sold on 11 July 1905
RenardLaird Brothers, Birkenhead26 October 18916 December 1892January 1894Sold for breaking on 4 April 1905
NigerNaval Construction & Armament, Barrow17 September 189117 December 189225 April 1893Became a minesweeper in 1909. Torpedoed by U-12 off Deal on 11 November 1914
SpeedyThornycroft, Chiswick4 January 189218 May 189320 February 1894Became a minesweeper in 1909. Sunk by a mine off the Humber on 3 September 1914
AntelopeDevonport Dockyard21 October 188912 July 1893May 1894Reduced to harbour service in 1910 and used as training ship at Devonport. Sold for breaking on 27 May 1919

References

    Bibliography
    Wikimedia Commons has media related to Alarm class torpedo gunboat.
    • Brown, Les (2023). Royal Navy Torpedo Vessels. Barnsley, UK: Seaforth Publishing. ISBN 978-1-3990-2285-9.
    • Colledge, J. J.; Warlow, Ben (2006) [1969]. Ships of the Royal Navy: The Complete Record of all Fighting Ships of the Royal Navy (Rev. ed.). London: Chatham Publishing. ISBN 978-1-86176-281-8.
    • Winfield, R.; Lyon, D. (2004). The Sail and Steam Navy List: All the Ships of the Royal Navy 1815–1889. London: Chatham Publishing. ISBN 978-1-86176-032-6. OCLC 52620555.
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