The English Channel, especially the Dover Straits at its eastern end, was one of the main Allied shipping routes during the First World War. It saw a variety of different types of traffic: supplies and troop movements for the British Expeditionary Force in France and Flanders; shipping heading for London, Britain’s biggest port; coastal shipping sailing between British ports; and coal shipments from Britain to France to replace supplies from French coalfields now occupied by the Germans. About 80-100 merchant ships passed through the Dover Straits each day.
German U-boat minelayers of the UC type were very active in minelaying in this area. The British employed trawlers as minesweepers. In the second half of 1916 an average of just under six merchant ships per month were sunk or damaged by mines in British waters. This rose to 10 in the first half of 1917 but then fell back to four in the second half of 1917. On average 178 mines a month were swept in 1916, rising to 355 in 1917.
An anti-submarine net barrage was also laid across the Straits, which was maintained by drifters, but in practice tides and current made the task of such small craft difficult even in good weather. They were at best armed with a 6 pounder gun and sometimes with just a machine gun, requiring them to be protected by destroyers and armed auxiliary steamers.
On 24 October 1916 Vice Admiral Sir Reginald Bacon, commanding the Dover Patrol, was warned that the German naval forces in Flanders had been reinforced by a flotilla of destroyers. He thought it unlikely that the Germans would attack the Straits because no troops were transported at night but that an attack on shipping in the Downs, an area off the north east coast of Kent, was likely.
He had defending Dunkirk the flotilla leader HMS Swift (2,170 tons, four 4 inch guns, two 18 inch torpedo tubes, 35 knots), four modern L class destroyers (966-1010 tons, three 4 inch guns, one .303 inch MG, four 21 inch torpedo tubes, 29 knots) on loan from the Harwich Force and four old destroyers, called 30 knotters because of their design speed (310-70 tons, one 12 pounder (76mm) and five 12 pounder (57mm) guns, two 18 inch torpedo tubes, 30 knots).
Four more L class destroyers were at Deal, defending the Downs.
Six Tribal class destroyers (855-1090 tons, two 4 inch or five 12 pounder (76mm) guns, two 18 torpedo tubes, 33 knots), two 30 knotters, two old torpedo boats (specifications varied but would have been small than the 30 knotters) and a P boat (613 tons, one 4 inch and one 2 pounder (40mm) AA guns, one 14 inch torpedo tubes, 20 knots) were at Dover.
The Tribals were assigned to the Dover Patrol because of their poor endurance. The P or Patrol boats were a wartime design with a low freeboard, a sharp turning circle and a deliberate resemblance to submarines, which it was hoped would allow them to close on U-boats and sink them by gunfire or ramming.
The wide range of displacements was a consequence of a British policy of giving different shipyards some discretion over ship design, provided that various criteria for speed, range, protection, armament etc were met.
That night 24 German destroyers put to sea, commanded by Kapitän Andreas Michelsen, commodore of the High Seas Fleet’s flotillas. They were divided into two flotillas, each split into two half flotillas. The 3rd Flotilla consisted of the 5th (seven ships) and 6th Half Flotillas (six ships), all armed with three 105mm (4.1 inch) guns and. The 9th Flotilla was made up of the 17th (six ships) and the 18th Half Flotillas (5 ships), armed with either three 105mm guns or three 88mm (3.45 inch) guns. All had six 50 cm (19.7 inch) torpedo tubes. They displaced 800-960 tons and were capable of 33.5-34 knots. The Germans called them High Seas Torpedo Boats but they are referred to as destroyers here as they were comparable to British destroyers.
The 9th Flotilla was to attack the transport line between Dover and Calais and the 3rd the drifters and the barrage. Each Half Flotilla would have its own area of operation. The 30 knotter HMS Flirt, supporting the drifters, saw but did not identify German destroyers at 2135. The Germans opened fire on the drifters just after 2200. They sank six out of 28 drifters, a trawler and HMS Flirt. The other drifters were able to escape into the darkness, though three were badly damaged.
The six Tribals at Dover were ordered to put to sea at 2250. Five minutes later the four L class destroyers at Dunkirk received the same instruction. The L class ships in the Downs were supposed to remain where they were but instead headed for Dunkirk because of two signalling errors. Fortunately for the British the Germans did not attack the Downs. The Germans attacked the transport line between 2300 and 2330 but sank only one of the 57 ships crossing the Channel, the transport Queen, whose crew were first allowed to board her lifeboats.
The Tribals failed to concentrate but came into contact with the 9th Flotilla as it withdrew from its attack on the transport line. HMS Nubian came under heavy fire at close range. She attempted to ram the last German torpedo boat but was instead torpedoed in the bow. She was put out of action and had to be towed back to port.
HMS Amazon, which had become detached from the other Tribals, encountered some destroyers that he captain assumed were L class ships. They were Germans., who opened fire, putting her after gun and two boilers out of action. They also damaged a trawler.
HMS Viking, Mohawk and Tartar engaged the Germans but a shell hit Mohawk and jammed her helm. Tartar followed her and Viking had to change course to avoid a collision, with the result that contact was lost. The Dunkirk destroyers saw gun flashes but were too far away to get into action. This action showed that the barrage had limited effect, as 14 British destroyers had crossed it without being damaged.
Nubian was too badly damaged to be repaired. On 8 November her sister ship HMS Zulu had her stern blown off by a mine. The two ships were put together by Chatham Dockyard and the combined ship was commissioned as HMS Zubian on 7 June 1917. She was credited with sinking the U-boat UC50 on 7 January 1918.
The Germans sunk six drifters, a trawler, an empty transport ship and a torpedo boat and damaged two destroyers and several auxiliaries, suffering only minor damage to SMS 91 in return. British human losses were 45 dead, four wounded and 10 captured. The dead included all the crew of Flirt, except for a boat party that had been lowered just before she was sunk to pick up survivors from the drifters. The German success was helped by their previous inactivity, which made the British complacent.
 M. Faulkner, A. D. Lambert, The Great War at Sea: A Naval Atlas 1914-1919, p. 105.
 L. Sondhaus, German Submarine Warfare in World War I: The Onset of Total War at Sea. Kindle Edition, locations 1902-50.
 Naval Staff Monograph (Historical) 1922 vol. vi, The Dover Patrol i. pp. 69-70; R. Gray, Conway’s All the World’s Fighting Ships, 1906-1921, pp. 71-72, 76, 96.
 J. S. Corbett, H. Newbolt, Naval Operations, 5 vols. vol. iv, p. 52 and footnote 2; Gray, Conway’s 1906-1921, pp. 168-69.
 Corbett, Newbolt, Naval. vol. iv, pp. 55-57; Faulkner, Lambert, Great, p. 113; M. D. Karau, The Naval Flank of the Western Front : The German Marinekorps Flandern, 1914-1918, p. 77.
 Corbett, Newbolt, Naval. vol. iv, pp. 58-62; Faulkner, Lambert, Great, p. 113.
 Naval Staff vol. vi. p. 82.
 Gray, Conway’s 1906-1921, p. 72.
 Karau, Naval, pp. 77, 79.