Acheron-class destroyer

For other ship classes of the same name, see Acheron class and I-class destroyer.

The Acheron class (renamed 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 the First World War. 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]}

HMS Acheron
Class overview
Name	Acheron-class destroyer
Builders	Cammell Laird J. I. Thornycroft J. Samuel White John Brown and Company R. W. Hawthorn Leslie & Company Swan Hunter & Wigham Richardson Vickers Ltd William Beardmore & Co William Denny & Brothers Yarrow & Co.
Operators	Royal Navy
Preceded by	Acorn class
Succeeded by	Acasta class
Built	1911–1912
In commission	1911–1922
Completed	23
Lost	3
General characteristics
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)
Installed power	Standard I-class: 13,500 shp (10,067 kW) Acheron, Ariel: 15,500 shp (11,558 kW) Lurcher, Oak, Firedrake: 20,000 shp (14,914 kW)
Propulsion	Standard I-class: 3 × Parsons steam turbines 3 × Yarrow-type oil-fired boilers 3 × shafts Ferret, Forester: 3 × Parsons steam turbines 3 × White-Forster oil-fired boilers 3 × shafts Hind, Hornet, Hydra: 2 × Brown-Curtis turbines 2 × Yarrow-type oil-fired boilers 2 × Shafts Oak, Lurcher, Firedrake:[1] 2 × Parsons turbines 3 × Yarrow oil-fired boilers 2 × shafts
Speed	27 kn (50 km/h; 31 mph) – 35 kn (64.8 km/h; 40.3 mph)
Armament	2 × BL 4-inch (101.6 mm) L/40 Mark VIII guns, mounting P Mark V 2 × QF 12-pounder (76 mm) 12 cwt guns, mounting P Mark I 2 × single tubes for 21-inch (530 mm) torpedoes

Design

Originally, 20 ships, including Acheron, were ordered but three more were completed by Yarrow & Company. The Acherons were generally repeats of the preceding Acorn- or H-class, although Acheron 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 kn (56.9 km/h; 35.3 mph) in trials.^[2]

Thornycroft specials

Acheron and Ariel were longer (253 ft (77 m)), had higher power (15,500 shp) and were faster, achieving 29.4 kn (54.4 km/h; 33.8 mph) in trials.^[2]

Yarrow specials (or "special I class")

Sir Alfred Yarrow maintained that it was possible to build strong, seaworthy destroyers with a speed of 32 kn (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.^[1] Firedrake, Lurcher and Oak were distinctive in appearance and indeed much faster. They all exceeded their contract speed, Lurcher making over 35 kn (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.^[3]

Evaluation

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.

Ships

Builders' I class

Name	Ship Builder	Launched	Fate
Acheron	John I. Thornycroft & Company, Woolston	27 June 1911	Sold 9 May 1921[4]
Archer	Yarrow & Company, Scotstoun, Glasgow	21 October 1911	Sold 9 May 1921[4]
Ariel	John I. Thornycroft & Company, Woolston	26 September 1911	Converted to fast minelayer in 1917. Mined while minelaying in North Sea 2 August 1918[5]
Attack	Yarrow & Company, Scotstoun, Glasgow	12 December 1911	Torpedoed or mined by German U-boat UC-34 off Alexandria 30 December 1917.[6]
Badger	William Denny & Brothers,[7] Dumbarton	11 July 1911	Sold 9 May 1921[4]
Beaver	William Denny & Brothers,[7] Dumbarton	6 October 1911	Sold May 1921

Admiralty I class

Name	Ship Builder	Launched	Fate
Defender	William Denny & Brothers, Dumbarton	30 August 1911	Sold 4 November 1921[4]
Druid	William Denny & Brothers, Dumbarton	4 December 1911[7]	Sold 9 May 1921[4]
Ferret	J. Samuel White & Company, Cowes	12 April 1911[7]	Converted to fast minelayer in 1917. Sold May 1921[7]
Forester	J. Samuel White & Company, Cowes	1 June 1911[7]	Sold November 1921[7]
Goshawk	William Beardmore & Company, Dalmuir	18 October 1911[7]	Sold November 1921[7]
Hind	John Brown & Company, Clydebank	28 July 1911[7]	Sold 9 May 1921[7]
Hornet	John Brown & Company, Clydebank	20 December 1911[7]	Sold 9 May 1921[7]
Hydra	John Brown & Company, Clydebank	19 February 1912[7]	Sold 9 May 1921[4]
Jackal	R. W. Hawthorn Leslie & Company, Hebburn	9 September 1911[7]	Sold September 1920[7]
Lapwing	Cammell Laird & Company, Birkenhead	29 July 1911[7]	Sold October 1921[7]
Lizard	Cammell Laird & Company, Birkenhead	10 October 1911[7]	Sold 4 November 1921[8]
Phoenix	Vickers, Barrow-in-Furness	9 October 1911	Torpedoed by the Austro-Hungarian submarine U-27 in the Adriatic Sea on 14 May 1918[9]
Sandfly	Swan Hunter & Wigham Richardson, Wallsend	26 July 1911[7]	Converted to fast minelayer in 1917. Sold May 1921[7]
Tigress	R. W. Hawthorn Leslie & Company, Hebburn	20 December 1911[7]	Sold 9 May 1921[4]

Yarrow Specials (or "Special I class")

Name	Ship Builder	Launched	Fate
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[8][4]

Notes

1. No class of ships were called J class.