The ''Sentinel''-class cruisers were a pair of

scout cruiser A scout cruiser was a type of warship of the early 20th century, which were smaller, faster, more lightly armed and armoured than protected cruisers or light cruisers, but larger than contemporary destroyers. Intended for fleet scouting duties a ...

s built for the

Royal Navy The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against F ...

in the first decade of the 20th century. The

sister ship A sister ship is a ship of the same class or of virtually identical design to another ship. Such vessels share a nearly identical hull and superstructure layout, similar size, and roughly comparable features and equipment. They often share a ...

s spent about half of the first decade of their careers in

reserve Reserve or reserves may refer to: Places * Reserve, Kansas, a US city * Reserve, Louisiana, a census-designated place in St. John the Baptist Parish * Reserve, Montana, a census-designated place in Sheridan County * Reserve, New Mexico, a US vi ...

and were based in home waters when on active duty. When the

First World War World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

began in August 1914 they were given coastal defence missions on the north eastern coast of Britain. The ships were transferred to the

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the e ...

in 1915 and then to the Aegean in mid-1916 where they remained until the end of the war in late 1918. was

paid off Ship commissioning is the act or ceremony of placing a ship in active service and may be regarded as a particular application of the general concepts and practices of project commissioning. The term is most commonly applied to placing a warship in ...

in 1919 and was

scrapped Scrap consists of recyclable materials, usually metals, left over from product manufacturing and consumption, such as parts of vehicles, building supplies, and surplus materials. Unlike waste, scrap has monetary value, especially recovered me ...

the following year, but supported the British attempt to intervene in the Russian Civil War for a few months after the end of the war. She also returned home in 1919, but served as a

training ship A training ship is a ship used to train students as sailors. The term is mostly used to describe ships employed by navies to train future officers. Essentially there are two types: those used for training at sea and old hulks used to house classr ...

for a few years before she was broken up in 1923.

Background and description

In 1901–1902, the Admiralty developed scout cruisers to work with

destroyer In naval terminology, a destroyer is a fast, manoeuvrable, long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against powerful short range attackers. They were originally developed in ...

flotilla A flotilla (from Spanish, meaning a small ''flota'' (fleet) of ships), or naval flotilla, is a formation of small warships that may be part of a larger fleet. Composition A flotilla is usually composed of a homogeneous group of the same class ...

s, leading their torpedo attacks and backing them up when attacked by other destroyers. In May 1902, it requested tenders for a design that was capable of , a protective deck, a range of and an armament of six quick-firing (QF) 12-pounder () 18 cwt guns,"Cwt" is the abbreviation for

hundredweight The hundredweight (abbreviation: cwt), formerly also known as the centum weight or quintal, is a British imperial and US customary unit of weight or mass. Its value differs between the US and British imperial systems. The two values are distingu ...

, 18 cwt referring to the weight of the gun. eight QF 3-pounder (47 mm) guns and two 18-inch (450 mm)

torpedo tube A torpedo tube is a cylindrical device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units (also referred to as torpedo launchers) installed aboa ...

s. It accepted four of the submissions and ordered one ship from each builder in the 1902–1903 Naval Programme and a repeat in the following year's programme. The two ships from

Vickers Vickers was a British engineering company that existed from 1828 until 1999. It was formed in Sheffield as a steel foundry by Edward Vickers and his father-in-law, and soon became famous for casting church bells. The company went public in 18 ...

became the ''Sentinel'' class. Four more 12-pounders were added to the specification in August. The ships had a

length between perpendiculars Length between perpendiculars (often abbreviated as p/p, p.p., pp, LPP, LBP or Length BPP) is the length of a ship along the summer load line from the forward surface of the stem, or main bow perpendicular member, to the after surface of the ster ...

of , a

beam Beam may refer to: Streams of particles or energy *Light beam, or beam of light, a directional projection of light energy **Laser beam *Particle beam, a stream of charged or neutral particles **Charged particle beam, a spatially localized grou ...

of and a draught of at

deep load The displacement or displacement tonnage of a ship is its weight. As the term indicates, it is measured indirectly, using Archimedes' principle, by first calculating the volume of water displaced by the ship, then converting that value into wei ...

. They displaced at normal load and at deep load. Their crew consisted of 289 officers and ratings.Friedman 2009, pp. 100, 294 The ''Sentinel''s differed from the other scout cruiser classes (the , and classes) in having a turtleback

forecastle The forecastle ( ; contracted as fo'c'sle or fo'c's'le) is the upper deck of a sailing ship forward of the foremast, or, historically, the forward part of a ship with the sailors' living quarters. Related to the latter meaning is the phrase " be ...

and shorter

funnel A funnel is a tube or pipe that is wide at the top and narrow at the bottom, used for guiding liquid or powder into a small opening. Funnels are usually made of stainless steel, aluminium, glass, or plastic. The material used in its construct ...

s. The ''Sentinel''-class ships were powered by a pair of four-cylinder triple-expansion steam engines, each driving one shaft, using steam provided by a dozen Vickers Express

water-tube boiler A high pressure watertube boiler (also spelled water-tube and water tube) is a type of boiler in which water circulates in tubes heated externally by the fire. Fuel is burned inside the furnace, creating hot gas which boils water in the steam-gene ...

s that exhausted into three funnels. The engines were designed to produce a total of which was intended to give a maximum speed of 25 knots.Roberts 1979, pp. 84–85 The ''Sentinels'' barely exceeded their design speed when they ran their

sea trial A sea trial is the testing phase of a watercraft (including boats, ships, and submarines). It is also referred to as a " shakedown cruise" by many naval personnel. It is usually the last phase of construction and takes place on open water, and ...

s in 1905. The scout cruisers soon proved too slow for this role as newer destroyers outpaced them. The sisters carried a maximum of of coal which gave them a range of at . The main armament of the ''Sentinel'' class consisted of ten QF 12-pounder 18-cwt guns.Friedman 2011, p. 112 Three guns were mounted abreast on the forecastle and the

quarterdeck The quarterdeck is a raised deck behind the main mast of a sailing ship. Traditionally it was where the captain commanded his vessel and where the ship's colours were kept. This led to its use as the main ceremonial and reception area on bo ...

, with the remaining four guns positioned

port and starboard Port and starboard are nautical terms for watercraft and aircraft, referring respectively to the left and right sides of the vessel, when aboard and facing the bow (front). Vessels with bilateral symmetry have left and right halves which are ...

amidships This glossary of nautical terms is an alphabetical listing of terms and expressions connected with ships, shipping, seamanship and navigation on water (mostly though not necessarily on the sea). Some remain current, while many date from the 17th t ...

. They also carried eight QF 3-pounder

Hotchkiss gun The Hotchkiss gun can refer to different products of the Hotchkiss arms company starting in the late 19th century. It usually refers to the 1.65-inch (42 mm) light mountain gun; there were also a navy (47 mm) and a 3-inch (76&nbs ...

s and two single mounts for 18-inch torpedo tubes, one on each

broadside Broadside or broadsides may refer to: Naval * Broadside (naval), terminology for the side of a ship, the battery of cannon on one side of a warship, or their near simultaneous fire on naval warfare Printing and literature * Broadside (comic ...

. The ships' protective deck armour ranged in thickness from and the

conning tower A conning tower is a raised platform on a ship or submarine, often armored, from which an officer in charge can conn the vessel, controlling movements of the ship by giving orders to those responsible for the ship's engine, rudder, lines, and gro ...

had armour inches thick.

Ships

Service history

The sisters were on and off active service in British waters for most of the first decade of their existence. After the beginning of the First World War, they were assigned to coastal defence duties, ''Sentinel'' on the Scottish coast and ''Skirmisher'' at the

Humber estuary The Humber is a large tidal estuary on the east coast of Northern England. It is formed at Trent Falls, Faxfleet, by the confluence of the tidal rivers Ouse and Trent. From there to the North Sea, it forms part of the boundary between the ...

. The ships were sent to the Mediterranean in 1915 and were then assigned to the Aegean Sea two years later and remained there until the end of the war. After returning home in 1919, ''Skirmisher'' was paid off and was sold for scrap in early 1920. ''Sentinel'' was sent to the

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...

for a few months after the end of the war as the British attempted to intervene in the Russian Civil War. She too returned home in 1919, but served as a training ship in 1920–1922 before being broken up in 1923.Preston 1985, p. 17

Notes

Footnotes

Bibliography

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External links

Sentinel class in World War I
{{WWI British ships Cruiser classes Ship classes of the Royal Navy World War I cruisers of the United Kingdom