The Acheron class (officially re-designated as the I class in October 1913) was a class

Ship class

A ship class is a group of ships of a similar design. This is distinct from a ship-type, which might reflect a similarity of tonnage or intended use. For example, the is a nuclear aircraft carrier of the Nimitz class....

 of twenty-three destroyer

Destroyer

In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...

s of the British Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

, all built under the 1910-11 Programme and completed between 1911 and 1912, which served during World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

. A further six ships were built to the same design for the Royal Australian Navy as River-class destroyers

River class torpedo boat destroyer

The River class was a class of six torpedo-boat destroyers operated by the Royal Australian Navy. Three were ordered for the Commonwealth Naval Forces in 1909; two were built in the United Kingdom, while a third was partially built, disassembled, then transported to Australia for reassembly...

. 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.No class of ships were designated as the J class.

Design

Originally, 20 ships, including Acheron, were ordered, but an additional three were completed by Yarrow & Company. Three River-class destroyers

River class torpedo boat destroyer

The River class was a class of six torpedo-boat destroyers operated by the Royal Australian Navy. Three were ordered for the Commonwealth Naval Forces in 1909; two were built in the United Kingdom, while a third was partially built, disassembled, then transported to Australia for reassembly...

 of the Royal Australian Navy

Royal Australian Navy

The Royal Australian Navy is the naval branch of the Australian Defence Force. Following the Federation of Australia in 1901, the ships and resources of the separate colonial navies were integrated into a national force: the Commonwealth Naval Forces...

 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

Acorn class destroyer

The Acorn class was a class of twenty destroyers of the Royal Navy all built under the 1909-1910 Programme, and completed between 1910 and 1911...

, 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 turbine

Steam 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 for evaluation purposes, achieving speeds of 30.7 knots (60.2 km/h) on trials.

Thornycroft specials

Acheron and Ariel were longer (77m), had higher installed power (15,500 shp) and were consequently faster, achieving 29.4 knots (57.6 km/h) on trials.

Yarrow specials (or "special I class")

Sir Alfred Yarrow

Alfred Yarrow

Sir Alfred Fernandez Yarrow, 1st Baronet, of Homestead was a British shipbuilder who started a shipbuilding dynasty, Yarrow Shipbuilders.-Life and career:...

 maintained that it was possible to build strong, seaworthy destroyers with a speed of 32 knots (62.7 km/h), 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 20000 shp, but carried the same armament. Firedrake, Lurcher and Oak were, however, distinctive in appearance and indeed much faster. They all exceeded their contract speed, Lurcher making over 35 knots (68.6 km/h).

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.

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.

Builders' I class

Name	Ship Builder	|Launched	|Fate
	John I. Thornycroft & Company John I. Thornycroft & Company John I. Thornycroft & Company Limited, usually known simply as Thornycroft was a British shipbuilding firm started by John Isaac Thornycroft in the 19th century.-History:... , Woolston	27 June 1911	Sold 9 May 1921
	Yarrow & Company, Scotstoun Scotstoun Scotstoun is a historic district of Glasgow, Scotland, west of Glasgow City Centre. It is bounded by Yoker and Knightswood to the west, Victoria Park, Broomhill and Whiteinch to the east, Jordanhill to the north and the River Clyde to the south... , Glasgow Glasgow Glasgow is the largest city in Scotland and third most populous in the United Kingdom. The city is situated on the River Clyde in the country's west central lowlands...	21 October 1911	Sold 9 May 1921
	John I. Thornycroft & Company, Woolston	26 September 1911	Converted to fast minelayer in 1917. Mined while minelaying Minelayer Minelaying is the act of deploying explosive mines. Historically this has been carried out by ships, submarines and aircraft. Additionally, since World War I the term minelayer refers specifically to a naval ship used for deploying naval mines...  in North Sea North Sea In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...  2 August 1918
	Yarrow & Company, Scotstoun, Glasgow	12 December 1911	Torpedoed or mined by German Kaiserliche Marine The Imperial German Navy was the German Navy created at the time of the formation of the German Empire. It existed between 1871 and 1919, growing out of the small Prussian Navy and Norddeutsche Bundesmarine, which primarily had the mission of coastal defense. Kaiser Wilhelm II greatly expanded...  U-boat U-boat U-boat is the anglicized version of the German word U-Boot , itself an abbreviation of Unterseeboot , and refers to military submarines operated by Germany, particularly in World War I and World War II...  UC-34 SM UC-34 SM UC-34 was a German Type UC II minelaying submarine or U-boat in the German Imperial Navy during World War I. The U-boat was ordered on 20 November 1915 and was launched on 6 May 1916...  off Alexandria Alexandria Alexandria is the second-largest city of Egypt, with a population of 4.1 million, extending about along the coast of the Mediterranean Sea in the north central part of the country; it is also the largest city lying directly on the Mediterranean coast. It is Egypt's largest seaport, serving...  30 December 1917.
	William Denny & Brothers, Dumbarton	11 July 1911	Sold 9 May 1921
	William Denny & Brothers, Dumbarton	6 October 1911	|Sold May 1921

Admiralty I class

Name	Ship Builder	Launched	Fate
	William Denny & Brothers, Dumbarton	30 August 1911	Sold 4 November 1921
	William Denny & Brothers, Dumbarton	4 December 1911	Sold 9 May 1921
	J. Samuel White & Company, Cowes Cowes Cowes is an English seaport town and civil parish on the Isle of Wight. Cowes is located on the west bank of the estuary of the River Medina facing the smaller town of East Cowes on the east Bank...	12 April 1911	Converted to fast minelayer in 1917. Sold May 1921
	J. Samuel White & Company, Cowes	|1 June 1911	Sold November 1921
	William Beardmore & Company, Dalmuir Dalmuir Dalmuir is an area on the western side of Clydebank, in West Dunbartonshire, Scotland.-Location:It is neighboured by the village of Old Kilpatrick, the Mountblow and Parkhall areas of Clydebank, as well as the town centre...	18 October 1911	Sold November 1921
	John Brown & Company John Brown & Company John Brown and Company of Clydebank was a pre-eminent Scottish marine engineering and shipbuilding firm, responsible for building many notable and world-famous ships, such as the , the , the , the , the , and the... , Clydebank Clydebank Clydebank is a town in West Dunbartonshire, in the Central Lowlands of Scotland. Situated on the north bank of the River Clyde, Clydebank borders Dumbarton, the town with which it was combined to form West Dunbartonshire, as well as the town of Milngavie in East Dunbartonshire, and the Yoker and...	28 July 1911	Sold 9 May 1921
	John Brown & Company, Clydebank	20 December 1911	Sold 9 May 1921
	John Brown & Company, Clydebank	19 February 1912	Sold 9 May 1921
	R. W. Hawthorn Leslie & Company, Hebburn Hebburn Hebburn is a small town situated on the south bank of the River Tyne in North East England, sandwiched between the towns of Jarrow and Bill Quay...	9 September 1911	Sold September 1920
	Cammell-Laird & Company, Birkenhead Birkenhead Birkenhead is a town within the Metropolitan Borough of Wirral in Merseyside, England. It is on the Wirral Peninsula, along the west bank of the River Mersey, opposite the city of Liverpool...	29 July 1911	Sold October 1921
	Cammell-Laird & Company, Birkenhead	10 October 1911	Sold 4 November 1921
	Vickers Vickers Limited Vickers Limited was a famous British engineering conglomerate that merged into Vickers-Armstrongs in 1927.-Early history:Vickers was formed in Sheffield as a steel foundry by the miller Edward Vickers and his father-in-law George Naylor in 1828. Naylor was a partner in the foundry Naylor &... , Barrow-in-Furness Barrow-in-Furness Barrow-in-Furness is an industrial town and seaport which forms about half the territory of the wider Borough of Barrow-in-Furness in the county of Cumbria, England. It lies north of Liverpool, northwest of Manchester and southwest from the county town of Carlisle...	9 October 1911	Torpedoed by the Austro-Hungarian Austria-Hungary Austria-Hungary , more formally known as the Kingdoms and Lands Represented in the Imperial Council and the Lands of the Holy Hungarian Crown of Saint Stephen, was a constitutional monarchic union between the crowns of the Austrian Empire and the Kingdom of Hungary in...  submarine in the Adriatic Sea Adriatic Sea The Adriatic Sea is a body of water separating the Italian Peninsula from the Balkan peninsula, and the system of the Apennine Mountains from that of the Dinaric Alps and adjacent ranges...  on 14 May 1918
	Swan Hunter & Wigham Richardson, Wallsend Wallsend Wallsend is an area in North Tyneside, Tyne and Wear, England. Wallsend derives its name as the location of the end of Hadrian's Wall. It has a population of 42,842.-Romans:...	26 July 1911	Converted to fast minelayer in 1917. Sold May 1921
	R. W. Hawthorn Leslie & Company, Hebburn	20 December 1911	Sold 9 May 1921

Yarrow Specials (or "Special I class")

Name	Ship Builder	|Launched	|Fate
	Yarrow & Company, Scotstoun Scotstoun Scotstoun is a historic district of Glasgow, Scotland, west of Glasgow City Centre. It is bounded by Yoker and Knightswood to the west, Victoria Park, Broomhill and Whiteinch to the east, Jordanhill to the north and the River Clyde to the south... , Glasgow Glasgow Glasgow is the largest city in Scotland and third most populous in the United Kingdom. The city is situated on the River Clyde in the country's west central lowlands...	9 April 1912	Sold 10 October 1922
	Yarrow & Company, Scotstoun, Glasgow	1 June 1912	Sold 9 June 1922
	Yarrow & Company, Scotstoun, Glasgow	5 September 1912	Sold May 1921

Australian River class

Name	Ship Builder	|Launched	|Fate
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