Convoys in World War I

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A transatlantic convoy approaching Brest on 1 November 1918. Photograph taken from aboard USS Rambler.

The

Dominions, and in 1915 by both it and the French Navy to cover their own troop movements for overseas service, they were not systematically employed by any belligerent navy until 1916. The Royal Navy was the major user and developer of the modern convoy system,[a] and regular transoceanic convoying began in June 1917. They made heavy use of aircraft for escorts, especially in coastal waters, an obvious departure from the convoy practices of the Age of Sail
.

As historian Paul E. Fontenoy put it, "[t]he convoy system defeated the

German submarine campaign."[1] From June 1917 on, the Germans were unable to meet their set objective of sinking 600,000 long tons (610,000 t) of enemy shipping per month. In 1918, they were rarely able to sink more than 300,000 long tons (300,000 t). Between May 1917 and the end of the war on 11 November 1918, only 154 of 16,539 vessels convoyed across the Atlantic had been sunk, of which 16 were lost through the natural perils of sea travel and a further 36 because they were stragglers.[1]

Development

Origins

The first large convoy of the war was the

airships.[3]

With the advent of

Aleksandr Vasiliyevich Kolchak—allowed the majority of the convoy to escape back to Norrköping.[5]

Revival

To cover trade with the neutral

U-boats based out of Flanders. Only one straggler was lost before the Germans announced unrestricted submarine warfare on 1 February 1917, and only six after that before the war's end despite 1,861 sailings.[1] The Holland convoys were sometimes referred to as the "Beef Trip" on account of the large proportion of food transported. They were escorted by destroyers of the Harwich Force and, later in the war, by AD Flying Boats based out of Felixstowe.[3]

The first convoys to sail after the German announcement were requested by the French Navy, desirous of defending British

Shetland Islands, the destination of the Norwegian convoys, for the Humber. This was to become a regular route. The Norwegian and coastal convoys included airships based out of Scotland (and in the latter case also Yorkshire).[3]

Although the British

Scillies.[3]

Maturation

The first transatlantic convoy left

Halifax during winter months.[1] The first regular convoy from the south Atlantic commenced on 31 July. Fast convoys embarked from Sierra Leone—a British protectorate—while slow ones left from Dakar in French West Africa.[1] Gibraltar convoys became regular starting on 26 July.[1]

Losses in convoy dropped to ten percent of those suffered by independent ships.

Walter H. Page—were both strong supporters of convoying and opponents of Germany's unrestricted submarine warfare. Shortly after the U.S. entered the war, Sims brought over 30 destroyers to the waters around Britain to make up the Royal Navy's deficit.[1]

The success of the convoys forced the

German U-boats in the Atlantic to divert their attention from inbound shipping to outbound. In response, the first outbound convoy left for Hampton Roads on 11 August 1917. It was followed by matching outbound convoys for each regular route. These were escorted by destroyers as they left Britain and were taken over by the typical cruiser flotillas as they entered the open ocean.[1]

Tonnage of British and neutral shipping lost in 1917 and 1918, showing failure of unrestricted U-boat warfare.[7] The German admiralty's target was only reached in the first few months, although it grossly overestimated its successes.[8]

The Germans again responded by changing strategy and concentrating on the

Somerset Calthorpe, began introducing the convoy system for the route from Port Said to Britain in mid-October 1917.[1] Calthorpe remained short of escorts and was unable to cover all Mediterranean trade, but his request to divert warships from convoy duty to the less effective Otranto Barrage was denied by the Admiralty.[10]

With the gradual success of the Mediterranean convoys, the Germans began to concentrate on attacking shipping in Britain's coastal waters, as convoyed vessels dispersed to their individual ports. Coastal convoy routes were only added gradually due to the limited availability of escorts, but by the end of the war almost all sea traffic in the war zones was convoyed.

sea planes. The organisation of these convoys had also been delegated by the Admiralty to local commanders.[3]

Admiralty resistance and objections

The main objection of the Admiralty to providing escorts for merchant shipping (as opposed to troop transits) was that it did not have sufficient forces. In large part, this was based on miscalculation. The Admiralty's estimates of the number of vessels requiring escort and the number of escorts required per convoy—it mistakenly assumed a 1:1 ratio between escorts and merchant vessels—were both wrong. The former error was exposed by Commander

R. G. H. Henderson of the Antisubmarine Division and Norman Leslie of the Ministry of Shipping, who showed that the Admiralty was relying on customs statistics that counted each arrival and departure, concluding that 2,400 vessels a week, translating into 300 ships a day, required an escort. In fact, there were only 140 ships per week, or 20 per day, on transoceanic voyages.[1]
But the manageability of the task was not the Admiralty's only objection.

It alleged that convoys presented larger and easier targets to U-boats, and harder object to defend by the Navy, raising the danger of the submarine threat rather than lowering it. It cited the difficulty of coordinating a rendezvous, which would lead to vulnerability while the merchant ships were in the process of assembling, and a greater risk of mines. The Admiralty also showed a distrust of the merchant skippers: they could not manoeuvre in company, especially considering that the ships would have various top speeds, nor could they be expected to keep station. At a conference in February 1917, some merchant captains raised the same concerns. Finally, the Admiralty suggested that a large number of merchantmen arriving simultaneously would be too much tonnage for the ports to handle, but this, too, was based in part on the miscalculation.[1]

In light of the

First Sea Lord because of the latter's opposition to the convoy system, which Prime Minister David Lloyd George had appointed Geddes to implement.[12][13]

Organisation

Types of convoy

According to John Abbatiello, there were four categories of convoy used during World War I. The first category consists of the short-distance convoys, such as those between Britain and its European allies, and between Britain and neutral countries. The commercial convoys between England and the Netherlands or Norway are examples, as are the coal convoys between England and France.

North Sea-class airships.[3] The third category is the so-called "ocean convoys" that safeguarded transoceanic commerce. They traversed the Atlantic from the U.S. or Canada in the north, or from British or French colonial Africa or Gibraltar in the south.[3] The fourth category is the "coastal convoys", those protecting trade and ship movements along the coast of Britain and within British home waters. Most coastal and internal sea traffic was not convoyed until mid-1918. These convoys involved the heavy use of aircraft.[3]

Structure of command

With the success of the convoy system, the Royal Navy created a new Convoy Section and a Mercantile Movements Division at the Admiralty to work with the Ministry of Shipping and the Naval Intelligence Division to organise convoys, routings and schedules.[1] Before this, the Norwegian convoys, coal convoys and Beef Trip convoys had often been arranged by local commanders. The Admiralty arranged the rendezvous, decided which ships would be escorted and in what order they would sail, but it left the composition of the escort itself to the Commander-in-Chief, Plymouth. The wing captain of the Southwest Air Group also received notification of the Admiralty's convoys, and provided air cover as they approached their ports.[3] The Enemy Submarine and Direction Finding Section and the code-breakers of Room 40 cooperated to give the convoy planners knowledge of U-boat movements.[1]

With the advent of coastal convoys, escort composition and technique fell into the hands of the district commanders-in-chief.[14]

Use of aircraft

In April 1918, the airship NS-3 escorted a convoy for 55 hours, including patrols at night both with and without moonlight. In complete darkness the airship had to stay behind the ships and follow their stern lights. The only value in such patrols was in maximising useful daylight hours by having the airships already aloft at dawn. In July, the Antisubmarine Division and the Air Department of the Admiralty considered and rejected the use of searchlights during night, believing the airships would render themselves vulnerable to surfaced U-boats. Testing of searchlights on aircraft revealed that the bomb payload needed to be much reduced to accommodate searchlight systems. Parachute flares offered better illumination (and were less illuminating of the airships′ positions), but they weighed in at 80 pounds (36 kg) each, making them too costly to drop unless the rough position of the enemy was already known. The Admiralty restricted the use of lights on airships for recognition, emergencies and under orders from senior naval officers only.[15]

Of the 257 ships sunk by submarines from World War I convoys, only five were lost while aircraft assisted the surface escort.[6] On 26 December 1917, as an airship was escorting three merchantmen out of Falmouth for their rendezvous with a convoy, they were attacked three times in the space of 90 minutes, torpedoing and sinking two of the vessels and narrowly missing the third before escaping. The airship had been 7 mi (6.1 nmi; 11 km) away at the time of the incident, which was one of the last of its kind. In 1918, U-boats attacked convoys escorted by both surface ships and aircraft only six times, sinking three ships in total out of thousands.[14] Because of the decentralised nature of the convoy system, the RNAS had no say in the composition or use of air escorts. The northeast of England led the way in the use of aircraft for short- and long-range escort duty, but shore-based aerial "hunting patrols" were widely considered a superior use of air resources. Subsequent historians have not agreed, although they have tended to overstress the actual use made of aircraft in convoy escort duty.[14] An Admiralty staff study in 1957 concluded that the convoy was the best defence against enemy attacks on shipping, and dismissed shore-based patrols while commending the use of air support in convoying.[16]

Notes

  1. ^ By "convoy system" is meant the systematic employment of convoys for all shipping or all shipping of a certain kind, such as transatlantic shipping, with naval escorts working on set schedules and routes.
  1. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z Paul E. Fontenoy, "Convoy System", The Encyclopedia of World War I: A Political, Social and Military History, Volume 1, Spencer C. Tucker, ed. (Santa Barbara: ABC-CLIO, 2005), 312–14.
  2. ^ Hirama Yoichi, "Anzac Convoy (October 1914)", The Encyclopedia of World War I: A Political, Social and Military History, Volume 1, Spencer C. Tucker, ed. (Santa Barbara: ABC-CLIO, 2005), 114.
  3. ^ a b c d e f g h i j k l m John J. Abbatiello, Anti-submarine Warfare in World War I: British Naval Aviation and the Defeat of the U-boats (Oxford: Routledge, 2006), 109–11.
  4. ^ Paul E. Fontenoy, "Submarine Warfare, Allied Powers", The Encyclopedia of World War I: A Political, Social and Military History, Volume 1, Spencer C. Tucker, ed. (Santa Barbara: ABC-CLIO, 2005), 1122–24. The author refers to a five-ship Turkish "convoy" driven ashore by the submarine Nerpa of the Russian Black Sea Fleet on 5 September 1915, where it was shelled by destroyers.
  5. ^ Claude R. Sasso and Spencer C. Tucker, "Kolchak, Aleksandr Vasiliyevich (1874–1920)", The Encyclopedia of World War I: A Political, Social and Military History, Volume 1, Spencer C. Tucker, ed. (Santa Barbara: ABC-CLIO, 2005), 642–43.
  6. ^ a b c Waters, John M. Jr. (1967). Bloody Winter. Princeton NJ: D. Van Nostrand Company. pp. 6–8.
  7. ^ Sims, Rear-Admiral William Snowden (1920). The Victory at Sea. London: John Murray. p. 344.
  8. ^ von Muller, Georg Alexander (1961). The Kaiser and his court : the diaries, notebooks, and letters of Admiral Georg Alexander von Muller, chief of the naval cabinet, 1914-1918. London: Macdonald.
  9. ^ a b c William P. McEvoy and Spencer C. Tucker, "Mediterranean Theater, Naval Operations (1914–1918)", The Encyclopedia of World War I: A Political, Social and Military History, Volume 1, Spencer C. Tucker, ed. (Santa Barbara: ABC-CLIO, 2005), 774–77.
  10. ^ Patricia Roberts, "Calthorpe, Sir Somerset (1864–1937)", The Encyclopedia of World War I: A Political, Social and Military History, Volume 1, Spencer C. Tucker, ed. (Santa Barbara: ABC-CLIO, 2005), 249–50.
  11. ^ Abbatiello (2006), 111.
  12. ^ Raymond Westphal Jr. and Spencer C. Tucker, "Geddes, Sir Eric Campbell (1875–1937)", The Encyclopedia of World War I: A Political, Social and Military History, Volume 1, Spencer C. Tucker, ed. (Santa Barbara: ABC-CLIO, 2005), 468–69.
  13. ^ Stephen Roskill, Hankey: Man of Secrets (London: Collins, 1970), Vol. I, pp. 442–443.
  14. ^ a b c Abbatiello (2006), 108.
  15. ^ Abbatiello (2006), 28–29.
  16. ^ For a revised edition of the staff study, cf. Freddie Barley and David Waters (eds.), The Defeat of the Enemy Attack of Shipping, 1939–45 (Aldershot: Ashgate for The Navy Records Society, 1997). Barley and Waters conclusions about hunting patrols vis-à-vis convoys were followed by Arthur Marder, From Dreadnought to Scapa Flow, 5 vols. (Oxford: Oxford University Press, 1961–70), quoted in Abbatiello (2006), 82.

External links

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