|Preceded by:||Acorn class|
|Succeeded by:||Acasta class|
|Operators:||Royal Australian Navy|
|Displacement:||750 to 790 tons|
|Length:||246 ft (75.0 m) to 252 ft (76.8 m)|
|Beam:||26 ft (7.9 m) to 26 ft 9 in (8.15 m)|
|Draught:||8 ft 6 in (2.59 m) to 9 ft (2.7 m)|
|Speed:||27 kn (50 km/h; 31 mph) – 35 kn (64.8 km/h; 40.3 mph)|
The Acheron class (officially re-designated as the I class in October 1913) was a class of twenty-three destroyers of the British Royal Navy, all built under the 1910-11 Programme and completed between 1911 and 1912, which served during World War I. A further six ships were built to the same design for the Royal Australian Navy as River-class destroyers. There was considerable variation between the design and construction of ships within this class, which should be considered as more of a post-build grouping than a homogeneous class.[Note 1]
Originally, 20 ships, including Acheron, were ordered, but an additional three were completed by Yarrow & Company. Three River-class destroyers of the Royal Australian Navy were laid down in British yards, with a further three built in Australia.
The Acherons were generally repeats of the preceding Acorn- or H-class, although Acheron herself and five others were builders' specials. They differed from the Acorns in having only two funnels, both of which were short, the foremost being thicker than the after stack. The 12-pounder guns were mounted slightly further forward than in the Acorns.
Variation within the class
Fourteen of the class were completed to an Admiralty standard design, although those built by John Brown and Company at Clydebank (Hind, Hornet and Hydra) had Brown-Curtis type turbines and only two shafts. Archer and Attack used steam at higher pressures and Badger and Beaver were completed with geared steam turbines for evaluation purposes, achieving speeds of 30.7 knots (56.9 km/h; 35.3 mph) on trials.
Acheron and Ariel were longer (77m), had higher installed power (15,500 shp) and were consequently faster, achieving 29.4 knots (54.4 km/h; 33.8 mph) on trials.
Yarrow specials (or "special I class")
Sir Alfred Yarrow maintained that it was possible to build strong, seaworthy destroyers with a speed of 32 knots (59 km/h; 37 mph), and eventually a contract for three such boats was placed with the firm. They were a little larger than the rest of the class, and developed 20,000 shp (15,000 kW), but carried the same armament. Like the John Brown-built boats Hind, Hydra and Hornet, they had only 2 shafts, with steam developed in 2 Yarrow-type water-tube boilers and delivered to 2 Parsons turbines. Firedrake, Lurcher and Oak were distinctive in appearance and indeed much faster. They all exceeded their contract speed, Lurcher making over 35 knots (65 km/h; 40 mph).
Conversion to minelayers
Ferret, Sandfly and Ariel were converted into fast minelaying destroyers in 1917, serving with the 20th Flotilla. They were each capable of laying 40 mines.
This class of torpedo boat destroyers (TBDs, or colloquially, "boats") handled well and were excellent sea boats; like similar classes of TBDs of the time, they had open bridges but were much drier at sea than was the norm.
Builders' I class
|Acheron||John I. Thornycroft & Company, Woolston||27 June 1911||Sold 9 May 1921|
|Archer||Yarrow & Company, Scotstoun, Glasgow||21 October 1911||Sold 9 May 1921|
|Ariel||John I. Thornycroft & Company, Woolston||26 September 1911||Converted to fast minelayer in 1917. Mined while minelaying in North Sea 2 August 1918|
|Attack||Yarrow & Company, Scotstoun, Glasgow||12 December 1911||Torpedoed or mined by German U-boat UC-34 off Alexandria 30 December 1917.|
|Badger||William Denny & Brothers, Dumbarton||11 July 1911||Sold 9 May 1921|
|Beaver||William Denny & Brothers, Dumbarton||6 October 1911||Sold May 1921|
Admiralty I class
|Defender||William Denny & Brothers, Dumbarton||30 August 1911||Sold 4 November 1921|
|Druid||William Denny & Brothers, Dumbarton||4 December 1911||Sold 9 May 1921|
|Ferret||J. Samuel White & Company, Cowes||12 April 1911||Converted to fast minelayer in 1917. Sold May 1921|
|Forester||J. Samuel White & Company, Cowes||1 June 1911||Sold November 1921|
|Goshawk||William Beardmore & Company, Dalmuir||18 October 1911||Sold November 1921|
|Hind||John Brown & Company, Clydebank||28 July 1911||Sold 9 May 1921|
|Hornet||John Brown & Company, Clydebank||20 December 1911||Sold 9 May 1921|
|Hydra||John Brown & Company, Clydebank||19 February 1912||Sold 9 May 1921|
|Jackal||R. W. Hawthorn Leslie & Company, Hebburn||9 September 1911||Sold September 1920|
|Lapwing||Cammell Laird & Company, Birkenhead||29 July 1911||Sold October 1921|
|Lizard||Cammell Laird & Company, Birkenhead||10 October 1911||Sold 4 November 1921|
|Phoenix||Vickers, Barrow-in-Furness||9 October 1911||Torpedoed by the Austro-Hungarian submarine U-27 in the Adriatic Sea on 14 May 1918|
|Sandfly||Swan Hunter & Wigham Richardson, Wallsend||26 July 1911||Converted to fast minelayer in 1917. Sold May 1921|
|Tigress||R. W. Hawthorn Leslie & Company, Hebburn||20 December 1911||Sold 9 May 1921|
Yarrow Specials (or "Special I class")
|Firedrake||Yarrow & Company, Scotstoun, Glasgow||9 April 1912||Sold 10 October 1922|
|Lurcher||Yarrow & Company, Scotstoun, Glasgow||1 June 1912||Sold 9 June 1922|
|Oak||Yarrow & Company, Scotstoun, Glasgow||5 September 1912||Sold May 1921|
Australian River class
|Parramatta||Fairfield Shipbuilding and Engineering Company Limited, Govan, Glasgow||9 February 1910||Used as accommodation by NSW Penal Department, and sold as scrap. Bow and stern sections salvaged as memorials in 1973|
|Yarra||William Denny & Brothers, Dumbarton||9 April 1910||Broken up 1929|
|Warrego||Laid down at Fairfield Shipbuilding and Engineering Company Limited, Govan and constructed at Cockatoo Dockyard, Sydney from parts||4 April 1911||Broken up 1930 at Cockatoo Dockyard|
|Huon||Cockatoo Dockyard, Sydney||19 December 1914||Reduced to reserve 7 June 1928 and sunk as a target off Sydney 10 April 1931|
|Swan||Cockatoo Dockyard, Sydney||11 December 1915||Paid off for disposal 15 May 1928 and broken up at Cockatoo Dockyard in 1930|
|Torrens||Cockatoo Dockyard, Sydney||28 August 1915||Reduced to reserve 19 July 1920 and sunk as a target 24 November 1930|
|Wikimedia Commons has media related to Australian River-class torpedo boat destroyer.|
- No class of ships were designated as the J class.
- Destroyers of the Royal Navy, 1893-1981, Maurice Cocker, 1983, Ian Allan ISBN 0-7110-1075-7
- The British Destroyer by Captain T D Manning CBE VRD RNVR (Ret'd), (Putnam, 1961)
- Conway's All the World's Fighting Ships, 1906-1921, Conway Maritime Press, 1985, Robert Gardiner ISBN 0-85177-245-5
- "Miscellenia" (PDF). The Engineer. 114: 39. 12 July 1912.
The vessel is 255ft. long by 25ft. 7in. beam, and is propelled by Parsons turbines driving two shafts, steam being supplied by three Yarrow water-tube boilers fitted with the firm's latest feed-heating devices
- "Battleships-Cruisers.co.uk website - Acheron Class". Archived from the original on 20 July 2008. Retrieved 2008-07-04.
- "I-class destroyers (extract from Jane's Fighting Ships of 1919)". Archived from the original on 3 June 2011. Retrieved 2008-10-19.
- Minesweeping and Minelaying from the Eleventh edition of the Encyclopædia Britannica, 1911
- ""Arrowsmith" List: Royal Navy WWI Destroyer Pendant Numbers". Retrieved 2008-07-01.
- "Royal Navy Casualty List, August 1918 - Naval history.net website". Retrieved 2008-10-17.
- "British Destroyers - Naval history.net website". Archived from the original on 5 October 2008. Retrieved 2008-10-25.
- Conway's All the World's Fighting Ships 1906-1921. London: Conway's Maritime Press. 1985. p. 75. ISBN 0-85177-245-5.
- "HMAS Warrego at the Australian War Memorial website". Archived from the original on 25 September 2008. Retrieved 2008-09-26.