Dover Patrol

The Dover Patrol was a Royal Navy command based in Dover and Dunkirk.

It operated continuously through the end of the war, with its strength primarily comprised of the Sixth Destroyer Flotilla, the Fifth Submarine Flotilla, the Downs Boarding Flotilla, and at times a collection of monitors. Its primary mission was to monitor barriers and defences at the eastern end of the English Channel to prevent U-boats from gaining access to western areas.

It also harrassed German fortifications on the coast of occupied Belgium.

History

Following the extra strain thrown on the Admiral of Patrols (Rear-Admiral George A. Ballard) and his staff caused by the beginning of minelaying and the evacuation of Antwerp, the Admiralty decided to create a separate command encompassing the patrols from the naval base at Dover, the naval base itself, and the Downs Boarding Flotilla. Command was transferred to Rear-Admiral The Honourable Horace L. A. Hood on 11 October, and he hoisted his flag on 13 October. He was given the title of "Rear-Admiral Commanding the Dover Patrol and Senior Naval Officer, Dover", with the short title "Rear-Admiral, Dover Patrol." His command consisted of the Sixth Destroyer Flotilla, Captain (D) Charles D. Johnson, the Third and Fourth Submarine Flotillas, the Downs Boarding Flotilla, and other vessels at Dover.

Hood's tenure in command was difficult, owing to growing pains and shifting demands upon his patchwork force. His initial orders were to maintain sea lanes across the channel, to lay and sweep mines to preserve the integrity of that passage, and to enforce the blockade of Germany by boarding and inspection operations. However, these commitments were soon augmented by increasing demands for naval bombardment employing whatever forces – destroyers, cruisers, obsolete battleships or monitors – could be made available by the Force. These demands vexed Hood, who doubted their necessity and the degree to which serious military efforts would accompany the noise and fury he visited upon the enemy, or at least the enemy terrain. Moreover, the Admiralty kept sending him battleships, which he had trouble mooring and protecting in the poorly sheltered waters of Dover Harbour. This placed him in an uncommon position for a naval commander: asking that people stop sending him reinforcements. Despite this tension, the Force was effective at least on occasion, as on 27 October, 1914 when its bombardment was so effective that it denied 4th Ersatz Division of III Reserve Corps control of the locks at the mouth of the Ijezer, which Belgian engineers were attempting to open so as to flood the surrounding country to hamper the German advance.

Reports of undiminished U-boat access to the Channel which were later found to be exaggerated prompted Churchill to replace Hood in mid-April 1915 with Vice-Admiral Reginald Bacon. Bacon commanded the force through January, 1918 and enjoyed ever-increasing numbers of monitors with which to finally meet bombardment needs.

The build up in strength was not only in warships. By October 1916 Auxiliary Patrol XI, covering the Dover Straits, had two yachts, 78 trawlers (56 of them fitted with minesweeping gear), 10 paddle minesweepers, 130 net drifters, 24 motor launches and five motor boats.

Bacon later wrote a two volume history of The Dover Patrol, in which he listed the achievements of the Dover Patrol: drifters, crewed by pre-war fishermen, maintained anti-submarine nets, which stretched for 45 miles in 1917; trawlers, also crewed by fishermen swept for mines across 250 miles per day; 120,000 merchant ships passed through the straits with light losses; 5,600,000 troops crossed the Channel without loss; the enemy held coast was bombarded from sea 28 times from ranges of up to 15 miles versus a maximum of 12 miles on ranges in peacetime; examination of merchant ships; and laying of minefields.

The first anti-submarine drifters arrived at Dover in January 1915 and there were over 130 of them there by June. They dragged an average of 1,000 yards of nets with a mesh pattern of 10 foot squares to a depth of 120 feet. Mines were attached to the nets in order to destroy any submarines that became enmeshed in them. The main problem was with the buoys that were intended to show where the nets were after they had been moved by a submarine that had become enmeshed in them. Bacon admitted that it was difficult to know how many U-boats had been caught in the nets and destroyed as mines were sometimes detonated by whales or other large fish. He claimed that some U-boats must have been lost to them as corpses in German naval uniform were sometimes found in the remains of a net.

The Strait was a maximum of 21 miles wide and 180 feet deep, with an average depth of 108 feet. This meant that 36 drifters could in theory block the passage, 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. German records show that S.M.S. U 8, scuttled on 4 March 1915 after being caught in the nets, forced to the surface and attacked by the destroyers H.M.S. Ghurka and H.M.S. Maori was the only U-boat lost to the Dover barrage in 1915 or 1916. It did, however, force the larger U-boats that were based in Germany to take the longer route round Scotland to the Atlantic, with the smaller UB coastal submarines and UC minelayers based in Flanders using the shorter route through the Dover Straits.

S.M.S. UB 10 was caught by the nets but worked herself clear after eight. Bacon believed that the cessation of U-boat activity in the Dover Straits from April to September 1915 was as a result of the nets. In fact, on 24 April, Admiral Reinhard Scheer, the C.-in-C. of the German High Seas Fleet, was ordered to carry out U-boat operations in accordance with prize law. He strongly believed that U-boat operations against commerce should be unrestricted, so ordered his U-boats to operate with his battlefleet rather than against commerce under prize laws..

The Allies used mines to combat U-boats but U-boats also laid mines. The 15 boats of the UC I class carried 12 mines but had no other armament other than a machine gun., with the exception of UC 11, which had a single torpedo tube. The 64 UC II class carried 18 mines and had two bow and one stern torpedo tubes. They initially had no deck gun although some were fitted with a 105mm gun in 1918. The 16 UC III class carried 14 mines and had the same torpedo armament as the UC IIs and either an 88mm or a 105mm gun.

Most German mines laid in British waters were laid by U-boats. In the second half of 1916 an average of about six merchant ships were sunk per month in British waters. This increased to 10 in the first half of 1917 but fell back to four in the second half of that year. On average 178 mines were swept in each month of 1916, rising to 355 in 1917. Even the English Channel was too big an area to sweep completely and only about 10 per cent of the waters around Dover could be swept regularly.

The Germans made several attacks by destroyers on the Dover Strait. The first of these, The Battle of Dover Strait on 26-27 October 1916 resulted in the sinking of the old destroyer H.M.S. Flirt, called a 30 knotter after her designed speed, the transport Queen, six drifters, a trawler and serious damage to the destroyers H.M.S. Nubian and H.M.S. Amazon. The Germans suffered no losses but missed opportunities to do more damage. The German success was helped by their previous inactivity, which made the British complacent. This action showed that the barrage had limited effect, as 14 British destroyers had crossed it without being damaged.

The Dover Patrol was reinforced by destroyers from the Humber and Harwich. Destroyers had then to be sent from the Grand Fleet to the Humber. This meant that the Grand Fleet might have had to leave part of the 4th Battle Squadron behind when it put to sea because of a lack of destroyers. The Germans were unable to base a large number of destroyers at Zeebrugge because of the risk of air attack, meaning that they face a lengthy canal journey from Bruges. This meant that the British normally detected their operations early, The Germans usually reinforced their Flanders Flotillas with extra destroyers from the High Seas Fleet before raids.

The second attack, on 23 November 1916, was ineffectual. Six German destroyers approached the Downs and fired at the drifters, damaging one without causing any casualties, before turning away before the British destroyers in the area could engage them. They made no attempt to enter the Downs, where over 100 merchantmen were moored. The Germans claimed to have bombarded Ramsgate, but no shells landed on land..

On 25-26 February 1917 the Germans sent destroyers to attack the traffic route from England to the Hook of Holland, the Downs and the barrage. The only effects of this raid were that the destroyer H.M.S. Laverock was struck by a torpedo that did not explode and that a bombardment the Thanet coast slightly damaged some houses..

The Dover Strait Action of 17 March, 1917 resulted in the sinking of the destroyer H.M.S. Paragon and the merchant ship SS Greypoint and the damaging of the destroyer H.M.S. Llewellyn.

The Second Battle of Dover Strait on 20-21 April 1917 was the first action in the Dover Straits to end in a major German defeat. The destroyers Template:DE-G42 and Template:DE-G85 were sunk by the British flotilla leaders H.M.S. Broke and H.M.S. Swift. This was a loss of almost 10 per cent of the destroyers based in Flanders and could not be replaced. The Germans therefore changed their strategy. Future attacks would be aimed at the Netherlands to UK convoys rather than the Channel patrols and barrage. Raids on shipping at the mouth of the Thames on 26 and 30 April encountered no shipping, although Margate was bombarded on 26 April.

The Action of 10 May, 1917 was fought between German destroyers raiding Netherlands to UK convoys and three British light cruisers and four destroyers. Neither side suffered any losses, but the British achieved their objective of protecting the convoy.

A week later the Germans attacked a convoy in fog, sinking the merchantman SS Ciro. The British destroyer H.M.S. Setter also sank after colliding with H.M.S. Sylph.

A further raid on 23 May was unsuccessful. Three days later a raiding force encountered two monitors and two French torpedo boats, but a fifteen minute gun battle caused no losses to either side.

The German surface forces in Flanders remained on the defensive for the remainder of 1917, fearing that the British might try an amphibious attack as part of their Passchendaele offensive. The British planned such an operation, but the land offensive did not go well enough for it to be carried out. The main tasks of the Flanders Flotillas in the rest of 1917 were minesweeping and coastal patrols. The British carried out a number of coastal bombardments, which were normally accompanied by major air battles, as both sides attempted to drive off the enemy's observation aircraft. There were some naval encounters, but none resulted in losses to either side. By the end of 1917 too many vessels had been transferred away from Flanders, mainly to take part in Operation Albion, an amphibious assault in the Baltic Sea, for them to carry out offensive operations.

By late 1917 the Admiralty was concerned that up to 30 U-boats a month were evading the barrage. Rear Admiral Roger Keyes, then the Admiralty's Director of Plans, proposed illuminating the mine and net barrage with searchlights at night in order to force U-boats to dive into the minefield. Bacon argued that this would reveal the barrage and make it vulnerable to attack. On 18 December he was ordered to institute an illuminated patrol. The next night S.M.S. UB 56 was forced to dive and was destroyed by mines. Admiral Sir John Jellicoe, the First Sea Lord, was a supporter of Bacon, but he was dismissed and replaced by Admiral Sir Rosslyn Wemyss in late December. Soon afterwards, Bacon was replaced by Keyes.

Keyes strengthened the minefields and employed a patrol of a monitor with a 12 or 15 inch gun, four 30 knot destroyers, patrol boats, 14 trawlers, 60 drifters, four motor launches and two paddle minesweepers. At night {{the minefield was illuminated by flares from the trawlers and the destroyers' searchlights.

The larger U-boats stopped using the Straits in February and the smaller boats based in Flanders became less active from April. They laid 404 minefields in 1917 but only 64 in 1918. A 1922 Admiralty document claims seven U-boats sunk in the Dover Strait area in the first four months of 1918 and six in the rest of the year, 12 of them being UB or UC type boats.

Uboat.net[1] lists five boats lost to mines and one to depth charges in the Dover area in the first four months of the year, with the seventh described as missing. It gives four lost to mines in the Dover area and one off Flanders in the rest of the year, with the final boat having been rammed by the steamer Queen Alexandra off Cherbourg.

The Germans bombarded Yarmouth on the evening of 14 January 1918. They did not encounter any British warships and the only German ships damaged was the torpedo boat Template:DE-V67, which struck a mine and had to be towed back to port. No ships on either side were sunk in minor actions on 23 January and 5 February.

The Action of 15 February, 1918 was the most successful German raid, sinking seven drifters and a trawler and severely damaging five drifters, a trawler and a paddle minesweeper without loss. The majority of the raids had been successful, with only one clear German defeat, but they were at least a month and as much as nine months apart, with the result that the losses from one attack had always been replaced by the time of the next one.

The Dover Strait Barrage therefore continued to keep U-boats out of the busy shipping lane of the English Channel, and to force them to sail round the British Isles on their way to the Atlantic, reducing their time on station. It is unclear why the Germans stopped attacking the Dover Barrage, especially when their last effort was so successful.

The Dover Patrol took part in the Ostend and Zeebrugge Raid on 23 April 1918, for which eight VCs were awarded, and the follow-up raid on Ostend on 9 May 1918, for which another three VCs were awarded. These raids were intended to close the canals that connected the ports of Zeebrugge and Ostend to the German naval base at Bruges. The first raid closed the Zeebrugge canal to larger destroyers until 14 May, but smaller torpedo boats and U-boats were able to use it and both raids failed to block the Ostend canal.

In 1918 the British launched a series of aerial bombing raids on the German naval bases in Flanders. From 17 February to 1 April five destroyers and torpedo boats and a U-boats were damaged by bombing. The Germans were forced to reinforce their fighter defences, but the raids became heavier from 10 May. Between then and 2 June 12 destroyers and torpedo boats and two U-boats were damaged by bombing. On the night of 28 May the Zeebrugge canal lock gate was hit by a bomb, putting it out of action for a week. On 9 June it was damaged by a coastal bombardment, closing the canal for the rest of the month to all shipping.

The English Channel, a vital communications link for British troops in France and Flanders, remained open to Allied shipping throughout the war. By April 1918 it was largely closed to U-boats.

In March 1919, the Dover Patrol was renamed the Dover Patrol Force, and it rapidly frittered away from there, losing its destroyers and submarines, leaving only a collection of minesweepers and "P" Boats by May.

The command was dissolved when Vice-Admiral Dampier hauled down his flag on 15 October, 1919.

In Command

• Rear-Admiral The Hon. Horace L. A. Hood, 3 October, 1914 – 13 April, 1915
• Vice-Admiral Sir Reginald H. S. Bacon, 13 April, 1915 – 1 January, 1918
• Acting Vice-Admiral Sir Roger J. B. Keyes, 1 January, 1918 – 20 March, 1919
• Vice-Admiral Cecil F. Dampier, 20 March, 1919 – 15 October, 1919

The Patrol was re-established on the outbreak of World War II.

• Commander Hugh C. Murdoch, September, 1939 – 26 September, 1939

Bibliography

• Naval Staff, Training and Staff Duties Division (1922). Naval Staff Monographs (Historical): Fleet Issue. Volume VI. The Dover Command. OU5413D (late CB917D). Copy at The National Archives ADM 186/613[2]
• Naval Staff, Training and Staff Duties Division (1924). Naval Staff Monographs (Historical): Fleet Issue. Volume X. Home Waters—Part I. From the Outbreak of War to 27 August, 1914. O.U. 5528 (late C.B. 917(H)). Copy at The National Archives. ADM 186/619.
• Naval Staff, Training and Staff Duties Division (1924). Naval Staff Monographs (Historical): Fleet Issue. Volume XI. Home Waters—Part II. September and October 1914. O.U. 5528 A (late C.B. 917(I)). Copy at The National Archives. ADM 186/620.
• Naval Staff, Training and Staff Duties Division (1939). Naval Staff Monographs (Historical): Fleet Issue. Volume XIX. Home Waters Part 9 May-July 1917. OU5528H. Copy at The National Archives. ADM 275/14[3]
• Bacon, Sir Roger (1919). The Dover Patrol, vol. i. London.
• Bacon, Sir Roger (1919). The Dover Patrol, vol. ii. London.
• Faulkner, Marcus (2015). The Great War at Sea: A Naval Atlas. Barnsley: Seaforth.
• Halpern, Paul (1994). A Naval History of World War I. London: UCL Press.
• Karau, Mark D (2003). The Naval Flank of the Western Front: The German MarineKorps Flandern, 1914-1918. Barnsley Seaforth.
• Newbolt, Henry (1928). Naval Operations. Vol. IV. London: Longmans, Green and Co..
• Newbolt, Henry (1931). Naval Operations. Vol. V. London: Longmans, Green and Co..
• Sheldon, Jack (2010). The German Army at Ypres 1914 and the Battle for Flanders. Barnsley: Pen & Sword Military. ISBN 978-1-84884-113-0.
• Sondhaus, Lawrence (2017). German Submarine Warfare in World War I: The Onset of Total War at Sea. Boulder MD: Rowman & Littlefield.