A full account of the design, construction and operation of the Royal Navy’s 42 monitors is contained in the book Big Gun Monitors by Ian Buxton.
WHEN WINSTON CHURCHILL and Jacky Fisher authorised a fleet of monitors to be built for the Royal Navy at the end of 1914, their main idea was to use them to bombard German naval bases to force the High Seas Fleet to sortie to face the Grand Fleet. To this end, four 6,150 ton vessels each carrying a twin 14-inch turret of American origin were ordered in November, followed by eith 5,900 ton vessels with a twin 12-inch in December and two 6,700-ton vessels in January 1915 with a twin 15-inch. By March, it was clear that the original intention was impractical so the plans were altered to use the monitor fleet to support operations against the Turks in the attempt to force the Dardanelles.
Meantime 22 smaller 600 ton monitors had been ordered, four with a single long range 9.2-inch Mark X (M15-18), ten with a short range 9.2-inch Mark VI (M19-28) and five with two modern 6-inch Mark XII (M29-33). With the first monitors nearing completion in May, Churchill ordered nine large and six small monitors to be sent out to the Dardanelles to support the landings made at Helles and Anzac in April. Heavy artillery was lacking ashore, yet battle-ships with their big guns were too vulnerable to mines and torpedoes close inshore. Their place was successfully taken by the monitors, designed essentially as expendable vessels with a shallow 10-foot draft and protective bulges, which could operate in such conditions.
Abercrombie was the first of the 14-inch monitors to arrive during July 1915 at the Allied naval base at Mudros, 50 miles west of the Dardanelles. She was soon followed by her sisters Roberts, Havelock and Raglan. Their big guns could range nearly 20,000 yards, so they were deployed immediately off the Gallipoli peninsula firing on the Turkish lines. One was normally anchored in the shelter of Mavro Island to counter Turkish batteries on the Asiatic shore. Havelock supported the Suvla landings in August, which linked up with the Australians and New Zealanders at Anzac, but failed to break through the peninsula to open up the Dardanelles and the way to Constantinople and the ally Russia.
Fifteen of the smaller monitors, M15-23 and M28-33, were used for close support, bombardments of other parts of the Turkish coastline and patrol work in the Aegean. Two of the 12-inch monitors arrived in the autumn, Earl Of Peterborough and Sir Thomas Picton, but the planned deployment of more of the class and the 15-inch monitors (Marshals Ney and Soult) has been cancelled after Churchill and Fisher left the Admiralty in May. These latter vessels were used off the Belgian coast to support the Allied flank on the Western Front and to bombard German forward naval bases.
With the evacuation of Gallipoli at the end of 1915, some of the monitors were withdrawn. Havelock and Roberts went home to be allocated to guardship duties at East Coast ports, where their low 7-knot speed would be little handicap. Others moved north to Salonika to support Allied operations against Bulgaria on the Macedonian Front. Four of the small monitors moved south to the Suez Canal area to protect the vital waterway against Turkish attacks. Australian troops were among those deployed in Sinai, who during 1916 stopped the Turks 30 miles from Port Said. Then as Allied forces were built up in Egypt, an advance was made along the Sinai coast towards Palestine. Initial assaults on Gaza were repulsed in the spring of 1917, but a new offensive was started in October. Supported by a heavy bombardment from Raglan, M15, M29, M31 and M32, the Turkish lines broke and the advance into Palestine continued into 1918, with the Anzac Corps playing an important part.
Other small monitors were involved in minor operations in the Eastern Mediterranean and Gulf of Akaba, but the best known was the destruction of the German cruiser Konigsberg. The latter had taken refuge in the shallow Rufiji River delta in East Africa, out of range of British ships patrolling offshore. Two shallow draft river monitors, which had originally been ordered for Brazil but taken over by the RN on the outbreak of war, were sent in to bring their two single 6-inch to destroy Konigsberg. In July 1915, Severn and Mersey fired 837 rounds to put the German ship out of action with the aid of aircraft spotting. Their sister Humber, who retained the original twin 6-inch turret, had remained in the Mediterranean, initially off the Anzac beaches, later in Egyptian waters.
In 1916, Earl of Peterborough and Sir Thomas Picton moved to the Adriatic to support the Italians against the Austrians. Based at Venice, their bombardments helped stem the Austrian advance after Caporetto in October 1917. The Italians had also developed a number of monitors, but these were mostly makeshift converted craft less successful than the British purpose-built ships.
After the evacuation from Gallipoli, several monitors were deployed watching the Dardanelles to try to prevent a sortie by the German battle cruiser Goeben and cruiser Breslau. Although their slow speed, light protection and high-explosive shells would be of limited use against the more powerful German vessels, there were two 12-inch gun battleships, Lord Nelson and Agamemnon, based nearby at Mudros. When the German ships did sortie on 20 January 1918, there was no prior warning. Raglan and M28 were caught at anchor at Imbros and quickly sunk by accurate gunfire. The battleships were too far away to help, although British defensive minefields sank Breslau and damaged Goeben.
After the Armistice, most of the monitors were soon paid off. Abercrombie, Earl of Peterborough and Sir Thomas Picton returned home in 1919, but most of the small monitors were laid up at Malta. Four were recommissioned in 1919 for operations against the Bolsheviks in the Black Sea. They were able to help the White Russians (anti- Bolsheviks) against the Bolsheviks in their initial successes in the Crimea; although after the monitors were withdrawn, the Bolsheviks gradually took control of the whole country in 1920.
Eight of the small monitors were sold to Anglo-Saxon Petroleum (now Shell) for conversion into coastal tankers. M16 was renamed Tiga and was used as a bunkering vessel at Sydney from 1924 to 1953. She was then sold to J. Stride at Sydney, but her ultimate fate is not recorded – perhaps readers can help?
No monitors were built between the wars. By the outbreak of World War II, only three of the large vessels remained – Erebus, Terror and Marshal Soult. The two former were 12-knot 8,000-ton vessels built in 1916 for operations off the Belgian Coast. Their two 15-inch guns could range 29,000 yards with 30° elevation. All other monitors not sold or scrapped were converted to depot ships or coastal minelayers.
During the 1930s, the large naval base at Singapore gradually took shape. Fixed defences with coastal artillery up to 15-inch calibre were planned, but to fill the gap while they were still building, Terror was sent out as guardship in 1933. In the event of war, she would be stationed east of the naval base, provided with Walrus spotting aircraft and linked up with the fortress plot ashore. Before the war, she made occasional cruises up the Malayan coast and carried out shoots at towed targets with armour-piercing shells.
After the five 15-inch had been installed at Singapore, together with 9.2-inch and 6- inch coast defences, Terror was assigned at the end of 1939 to the Mediterranean to reinforce the naval forces depleted by transfers to home waters. Arriving at Malta in April 1940, she was used as an anti-aircraft guardship whilst the island’s AA defences were being strengthened. After helping beat off Italian air attacks, she moved to Suda Bay at Crete in November as guardship at this forward naval base. Then came her opportunity to revert to her originally designed role of coastal bombardment. A major offensive against the Italian Army threatening Egypt and the Suez Canal was planned for December.