This is a list of

monitor Monitor or monitor may refer to: Places * Monitor, Alberta * Monitor, Indiana, town in the United States * Monitor, Kentucky * Monitor, Oregon, unincorporated community in the United States * Monitor, Washington * Monitor, Logan County, West ...

s of 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 ...

of the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...

Key

''Humber''-class

The ''Humber''-class monitors were three

river monitor River monitors are military craft designed to patrol rivers. They are normally the largest of all riverine warships in river flotillas, and mount the heaviest weapons. The name originated from the US Navy's , which made her first appearance in ...

s under construction for the

Brazilian Navy ) , colors= Blue and white , colors_label= Colors , march= "Cisne Branco" ( en, "White Swan") (same name as training ship ''Cisne Branco'' , mascot= , equipment= 1 multipurpose aircraft carrier7 submarines6 frigates2 corvettes4 amphibious war ...

in Britain in 1913, all three were taken over by the

shortly before the outbreak of 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 ...

and were commissioned as small monitors, seeing extensive service during the war.

''Abercrombie''-class

The ''Abercrombie''-class monitors came about when

Bethlehem Steel The Bethlehem Steel Corporation was an American steelmaking company headquartered in Bethlehem, Pennsylvania. For most of the 20th century, it was one of the world's largest steel producing and shipbuilding companies. At the height of its succe ...

in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

, the contracted supplier of the main armament for the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

battleship being built in Germany, instead offered to sell the four

14"/45 caliber gun The 14"/45 caliber gun, (spoken "fourteen-inch-forty-five-caliber"), whose variations were known initially as the Mark 1, 2, 3, and 5, and, when upgraded in the 1930s, were redesignated as the Mark 8, 9, 10, and 12. They were the first guns to b ...

twin

gun turret A gun turret (or simply turret) is a mounting platform from which weapons can be fired that affords protection, visibility and ability to turn and aim. A modern gun turret is generally a rotatable weapon mount that houses the crew or mechani ...

s to the Royal Navy on 3 November 1914, the ships were laid down and launched within six months, seeing service throughout the war.

''Lord Clive''-class

The ''Lord Clive''-class monitors, sometimes referred to as the ''General Wolfe''-class, were built to meet the need for more shore bombardment ships, using twin gun turrets taken from decommissioned ''Majestic''-class

pre-dreadnought Pre-dreadnought battleships were sea-going battleships built between the mid- to late- 1880s and 1905, before the launch of in 1906. The pre-dreadnought ships replaced the ironclad battleships of the 1870s and 1880s. Built from steel, protec ...

battleships. Three of the ships, HMS ''General Wolfe'', ''Lord Clive'' and ''Prince Eugene'', were converted to take the

BL 18 inch Mk I naval gun The BL 18-inch Mk I naval gun was a breech-loading naval rifle used by the Royal Navy during World War I. It was the largest and heaviest gun ever used by the British. Only the Second-World-War Japanese 46 cm/45 Type 94 had a larger calibre, , ...

that had originally been allocated to .

''Marshal Ney''-class

The ''Marshal Ney''-class monitors were built to use the two modern 15-inch turrets made available by the redesign of and as battlecruisers.

''Gorgon''-class

The ''Gorgon''-class monitors were originally built as

coastal defence ship Coastal defence ships (sometimes called coastal battleships or coast defence ships) were warships built for the purpose of coastal defence, mostly during the period from 1860 to 1920. They were small, often cruiser-sized warships that sacrifi ...

s for the

Royal Norwegian Navy The Royal Norwegian Navy ( no, Sjøforsvaret, , Sea defence) is the branch of the Norwegian Armed Forces responsible for naval operations of Norway. , the Royal Norwegian Navy consists of approximately 3,700 personnel (9,450 in mobilized state, ...

, but requisitioned for British use.

''M15''-class

The ''M15''-class monitors were fourteen ships ordered in March 1915, as part of the War Emergency Programme of ship construction, mounting 9.2 inch Mk VI gun turrets removed from the and the Mk X turrets held in stock for the and s.

''M29''-class

The ''M29''-class monitors were five ships ordered in March 1915, as part of the War Emergency Programme of ship construction.

''Erebus''-class

The ''Erebus''-class monitors were two ships mounting a single twin

BL 15 inch Mk I naval gun The BL 15-inch Mark I succeeded the BL 13.5-inch Mk V naval gun. It was the first British 15-inch (381 mm) gun design and the most widely used and longest lasting of any British designs, and arguably the most successful heavy gun ever devel ...

turret. They saw active service in World War I off the Belgian coast, were placed in reserve between the wars then served in World War II, with ''Terror'' being lost in 1941 and ''Erebus'' surviving to be scrapped in 1946.

''Roberts''-class

The ''Roberts''-class monitors were two ships mounting a single twin

turret built during the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...

, featuring shallow draught for operating inshore, broad beam to give stability and a high observation platform to observe fall of shot.

References

* {{Commons category, Monitors of the United Kingdom Monitors Royal Navy monitors Royal Navy monitors