Acheron-class destroyer

HMS Acheron
Class overview
Name:	Acheron-class destroyer
Operators:	Royal Navy
Preceded by:	Acorn class
Succeeded by:	Acasta class
Built:	1911–1912
In commission:	1911–1922
Completed:	23
Lost:	3
Class overview
Name:	River-class destroyer
Operators:	Royal Australian Navy
Built:	1910–1915
In commission:	1911–1925
Completed:	6
Lost:	0
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

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.^[2] 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]}

Design

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.^[3]

Thornycroft specials

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.^[3]

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.^[1] 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.^[4]

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

Admiralty I class

Yarrow Specials (or "Special I class")

Australian River class

Wikimedia Commons has media related to Australian River-class torpedo boat destroyer.

Notes

References

• 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

Acheron-class (or I-class) destroyers
Royal Navy	Admiralty Ferret Forester Sandfly Hind Lapwing Defender Jackal Phoenix Lizard Goshawk Druid Hornet Tigress Hydra Builders' Acheron Badger Ariel Beaver Archer Attack Yarrow Specials Firedrake Lurcher Oak
Royal Australian Navy River class	Parramatta Yarra Warrego Huon Torrens Swan
Preceded by: Acorn class Followed by: Acasta class
List of destroyers of the Royal Navy List of destroyers of the Royal Australian Navy