The M class, more properly known as the Admiralty M class, were a class of 85 destroyers built for the Royal Navy of United Kingdom that saw service during World War I. All ships were built to an identical – Admiralty – design, hence the class name. 18 other vessels which were officially included within the 'M' class were built to variant designs by three specialist builders – 10 by Yarrow, 6 by Thornycroft (who also built another 6 to the standard Admiralty design), and 2 by Hawthorn Leslie; these are covered in other articles.

This article includes a list of general references, but it lacks sufficient corresponding inline citations. (January 2013)

Quick Facts Class overview, General characteristics ...

HMS Pasley
Class overview
Operators	Royal Navy
Preceded by	L class
Succeeded by	R class
Subclasses	Thornycroft M class Yarrow M class Hawthorn M class Yarrow Later M class
Built	1914–1916
In commission	1915–1923
Completed	85
General characteristics
Type	Destroyer
Displacement	900 long tons (914 t) (normal) 1,100 long tons (1,118 t) full load
Length	273 ft 4 in (83.3 m) (o/a)
Beam	26 ft 8 in (8.1 m)
Draught	8 ft 6 in (2.6 m)
Installed power	4 Yarrow boilers 25,000 shp (18,642 kW)
Propulsion	3 shafts; 1 steam turbine set
Speed	34 knots (63 km/h; 39 mph)
Range	3,710 nmi (6,870 km; 4,270 mi) at 15 knots (28 km/h; 17 mph)
Complement	80
Armament	3 × single 4 in (102 mm) guns 2 × single 2-pdr (40 mm (1.6 in)) gun 2 × twin 21 in (533 mm) torpedo tubes

Close

The Admiralty design was based on the preceding L class but modified to produce an increase in speed by approximately 6 knots (11 km/h; 6.9 mph). All ships built to the Admiralty design had three identical narrow, circular funnels (this did not apply to the 18 ships built by the specialist yards).

An original intention to order 20 destroyers in this year's Programme was reduced to 16 vessels. Three destroyers already under construction were purchased from Yarrow, two from Thornycroft and two from Hawthorn Leslie to these builders' individual designs, and these are listed in separate articles. Three further ships had been projected under the Programme – and named Marksman, Menace and Monitor; however these three ships were cancelled before being contracted to any specific builder (although J. Samuel White & Company, at Cowes were the intended builder), in favour of two Marksman-class leaders. Thus just six vessels were built to the Admiralty design under the 1913–14 Naval Programme. These differed from the wartime vessels by being 1,010 tons full load, with slightly smaller dimensions.

All the following vessels were ordered in five batches as part of the War Emergency Programme. Wartime builds omitted the cruising turbines originally specified and carried by the pre-war sub-group. The funnel heights were also raised compared with the pre-war vessels, and the second 4 in gun was mounted on a bandstand, as with the earlier L-class destroyers. Partridge, Norman, Maenad, Ophelia and Observer were later fitted to carry a kite balloon.