A convoy is a group of vehicles, typically motor vehicles or ships, traveling together for mutual support and protection. Often, a convoy is organized with armed defensive support and can help maintain cohesion within a unit. It may also be used in a non-military sense, for example when driving through remote areas.
Naval convoys have been in use for centuries, with examples of merchant ships traveling under naval protection dating to the 12th century. [1] The use of organized naval convoys dates from when ships began to be separated into specialist classes and national navies were established. [2]
By the French Revolutionary Wars of the late 18th century, effective naval convoy tactics had been developed to ward off pirates and privateers. Some convoys contained several hundred merchant ships. The most enduring system of convoys were the Spanish treasure fleets, that sailed from the 1520s until 1790.
When merchant ships sailed independently, a privateer could cruise a shipping lane and capture ships as they passed. Ships sailing in convoy presented a much smaller target: a convoy was as hard to find as a single ship. Even if the privateer found a convoy and the wind was favourable for an attack, it could still hope to capture only a handful of ships before the rest managed to escape, and a small escort of warships could easily thwart it. As a result of the convoy system's effectiveness, wartime insurance premiums were consistently lower for ships that sailed in convoys. [2]
Many naval battles in the Age of Sail were fought around convoys, including:
By the end of the Napoleonic Wars, the Royal Navy had in place a sophisticated convoy system to protect merchant ships. [2] Losses of ships travelling out of convoy, however, were so high that no merchant ship was allowed to sail unescorted. [1]
In the early 20th century, the dreadnought changed the balance of power in convoy battles. Steaming faster than merchant ships and firing at long ranges, a single battleship could destroy many ships in a convoy before the others could scatter over the horizon. To protect a convoy against a capital ship required providing it with an escort of another capital ship, at very high opportunity cost (i.e. potentially tying down multiple capital ships to defend different convoys against one opponent ship).
Battleships were the main reason that the British Admiralty did not adopt convoy tactics at the start of the first Battle of the Atlantic in World War I. But the German capital ships had been bottled up in the North Sea, and the main threat to shipping came from U-boats. From a tactical point of view, World War I–era submarines were similar to privateers in the age of sail. These submarines were only a little faster than the merchant ships they were attacking, and capable of sinking only a small number of vessels in a convoy because of their limited supply of torpedoes and shells. The Admiralty took a long time to respond to this change in the tactical position, and in April 1917 convoys were trialled, before being officially introduced in the Atlantic in September 1917.
Other arguments against convoys were raised. The primary issue was the loss of productivity, as merchant shipping in convoy has to travel at the speed of the slowest vessel in the convoy and spent a considerable amount of time in ports waiting for the next convoy to depart. Further, large convoys were thought to overload port resources.
Actual analysis of shipping losses in World War I disproved all these arguments, at least so far as they applied to transatlantic and other long-distance traffic. Ships sailing in convoys were far less likely to be sunk, even when not provided with an escort. The loss of productivity due to convoy delays was small compared with the loss of productivity due to ships being sunk. Ports could deal more easily with convoys because they tended to arrive on schedule and so loading and unloading could be planned.
In his book On the Psychology of Military Incompetence , Norman Dixon suggested that the hostility towards convoys in the naval establishment were in part caused by a (sub-conscious) perception of convoys as effeminating, due to warships having to care for civilian merchant ships. [3] Convoy duty also exposes the escorting warships to the sometimes hazardous conditions of the North Atlantic, with only rare occurrences of visible achievement (i.e. fending off a submarine assault).
The British adopted a convoy system, initially voluntary and later compulsory for almost all merchant ships, the moment that World War II was declared. Each convoy consisted of between 30 and 70 mostly unarmed merchant ships. [4] Canadian, and later American, supplies were vital for Britain to continue its war effort. The course of the Battle of the Atlantic was a long struggle as the Germans developed anti-convoy tactics and the British developed counter-tactics to thwart the Germans.
The capability of a heavily armed warship against a convoy was dramatically illustrated by the fate of Convoy HX 84. On November 5, 1940, the German heavy cruiser Admiral Scheer encountered the convoy. Maiden, Trewellard, and Kenbame Head were quickly destroyed, and Beaverford and Fresno City falling afterwards. Only the sacrifices of the armed merchant cruiser HMS Jervis Bay and the freighter Beaverford to stall the Scheer, in addition to failing light, allowed the rest of the convoy to escape.
The deterrence value of a battleship in protecting a convoy was also dramatically illustrated when the German light battleships (referred by some as battlecruisers) Scharnhorst and Gneisenau, mounting 11 in (28 cm) guns, came upon an eastbound British convoy (HX 106, with 41 ships) in the North Atlantic on February 8, 1941. When the Germans detected the slow but well-protected battleship HMS Ramillies escorting the convoy, they fled the scene rather than risk damage from her 15 in (38 cm) guns.
The enormous number of vessels involved and the frequency of engagements meant that statistical techniques could be applied to evaluate tactics: an early use of operational research in war.
Prior to overt participation in World War II, the US was actively engaged in convoys with the British in the North Atlantic Ocean, primarily supporting British activities in Iceland. [5]
After Germany declared war on the US, the US Navy decided not to organize convoys on the American eastern seaboard. US Fleet Admiral Ernest King ignored advice on this subject from the British, as he had formed a poor opinion of the Royal Navy early in his career. The result was what the U-boat crews called their Second Happy Time, which did not end until convoys were introduced. [2] [ citation needed ]
In the Pacific Theater of World War II, Japanese merchant ships rarely traveled in convoys. Japanese destroyers were generally deficient in antisubmarine weaponry compared to their Allied counterparts, and the Japanese navy did not develop an inexpensive convoy escort like the Allies' destroyer escort/frigate until it was too late. In the early part of the conflict, American submarines in the Pacific were ineffective as they suffered from timid tactics, faulty torpedoes, and poor deployment, while there were only small numbers of British and Dutch boats. U.S. Admiral Charles A. Lockwood's efforts, coupled with strenuous complaints from his captains, rectified these problems and U.S. submarines became much more successful by war's end. As a result, the Japanese merchant fleet was largely destroyed by the end of the war. Japanese submarines, unlike their U.S. and German equivalents, focused on U.S. battle fleets rather than merchant convoys, and while they did manage some early successes, sinking two U.S. carriers, they failed to significantly inhibit the invasion convoys carrying troops and equipment in support of the U.S. island-hopping campaign. [2]
Several notable battles in the South Pacific involved Allied bombers interdicting Japanese troopship convoys which were often defended by Japanese fighters, notable Guadalcanal (13 November 1942), Rabaul (5 January 1943), and the Battle of the Bismarck Sea (2–4 March 1943).
At the Battle off Samar, the effectiveness of the U.S. Navy's escorts was demonstrated when they managed to defend their troop convoy from a much larger and more powerful Japanese battle-fleet. The Japanese force comprised four battleships and numerous heavy cruisers, while the U.S. force consisted of escort carriers, destroyers, and destroyer escorts. Large numbers of American aircraft (albeit without much anti-ship ordnance other than torpedoes) and aggressive tactics of the destroyers (with their radar-directed gunfire) allowed the U.S. to sink three Japanese heavy cruisers at the cost of one escort carrier and three destroyers.
The German anti-convoy tactics included:
The Allied responses included:
They were also aided by
Many naval battles of World War II were fought around convoys, including:
The convoy prefix indicates the route of the convoy. For example, 'PQ' would be Iceland to Northern Russia and 'QP' the return route.
The success of convoys as an anti-submarine tactic during the world wars can be ascribed to several reasons related to U-boat capabilities, the size of the ocean and convoy escorts.
In practice, Type VII and Type IX U-boats were limited in their capabilities. Submerged speed and endurance was limited and not suited for overhauling many ships. Even a surfaced U-boat could take several hours to gain an attack position. Torpedo capacity was also restricted to around fourteen (Type VII) or 24 (Type IX), thus limiting the number of attacks that could be made, particularly when multiple firings were necessary for a single target. There was a real problem for the U-boats and their adversaries in finding each other; with a tiny proportion of the ocean in sight, without intelligence or radar, warships and even aircraft would be fortunate in coming across a submarine. The Royal Navy and later the United States Navy each took time to learn this lesson. Conversely, a U-boat's radius of vision was even smaller and had to be supplemented by regular long-range reconnaissance flights.
For both major allied navies, it had been difficult to grasp that, however large a convoy, its "footprint" (the area within which it could be spotted) was far smaller than if the individual ships had traveled independently. In other words, a submarine had less chance of finding a single convoy than if it were scattered as single ships. Moreover, once an attack had been made, the submarine would need to regain an attack position on the convoy. If, however, an attack were thwarted by escorts, even if the submarine had escaped damage, it would have to remain submerged for its own safety and might only recover its position after many hours' hard work. U-boats patrolling areas with constant and predictable flows of sea traffic, such as the United States Atlantic coast in early 1942, could dismiss a missed opportunity in the certain knowledge that another would soon present itself.
The destruction of submarines required their discovery, an improbable occurrence on aggressive patrols, by chance alone. Convoys, however, presented irresistible targets and could not be ignored. For this reason, the U-boats presented themselves as targets to the escorts with increasing possibility of destruction. In this way, the Ubootwaffe suffered severe losses, for little gain, when pressing pack attacks on well-defended convoys.
The largest convoy effort since World War II was Operation Earnest Will, the U.S. Navy's 1987–88 escort of reflagged Kuwaiti tankers in the Persian Gulf during the Iran–Iraq War.
In the present day, convoys are used as a tactic by navies to deter pirates off the coast of Somalia from capturing unarmed civilian freighters who would otherwise pose easy targets if they sailed alone.
The word "convoy" is also associated with groups of road vehicles being driven, mostly by volunteers, to deliver humanitarian aid, supplies, and—a stated objective in some cases—"solidarity". [6]
In the 1990s these convoys became common traveling from Western Europe to countries of the former Yugoslavia, in particular Bosnia and Kosovo, to deal with the aftermath of the wars there. They also travel to countries where standards of care in institutions such as orphanages are considered low by Western European standards, such as Romania; and where other disasters have led to problems, such as around the Chernobyl disaster in Belarus and Ukraine.
The convoys are made possible partly by the relatively small geographic distances between the stable and affluent countries of Western Europe, and the areas of need in Eastern Europe and, in a few cases, North Africa and even Iraq. They are often justified because although less directly cost-effective than mass freight transport, they emphasise the support of large numbers of small groups, and are quite distinct from multinational organisations such as United Nations humanitarian efforts.
Truckers' convoys consisting of semi-trailer trucks and/or petrol tankers are more similar to a caravan than a military convoy.
Truckers' convoys were created as a byproduct of the U.S.' national 55 mph speed limit and 18-wheelers becoming the prime targets of speed traps. Most truckers had difficult schedules to keep and as a result had to maintain a speed above the posted speed limit to reach their destinations on time. Convoys were started so that multiple trucks could run together at a high speed with the rationale being that if they passed a speed trap the police would only be able to pull over one of the trucks in the convoy. When driving on a highway, convoys are also useful to conserve fuel by drafting.
The film Convoy, inspired by a 1975 song of the same name, explores the camaraderie between truck drivers, where the culture of the CB radio encourages truck drivers to travel in convoys.
Truck convoys are sometimes organized for fundraising, charity, or promotional purposes. They can also be used as a form of protest, such as the Canada convoy protest in 2022.
The Highway Code of several European countries (Norway, Italy, Greece, Netherlands, Germany, Austria, Switzerland, possibly more) includes special rights for marked convoys. They have to be treated like a single vehicle. If the first vehicle has passed an intersection, all others may do so without interruption. If other road users overtake the convoy, they are not allowed to split into the queue. Clear and uniform marking has been required in court decisions for these rights to apply. Operating such convoy usually needs special permission, but there are exemptions for emergency and catastrophe intervention. Common practice is, to operate with the same style of marking as NATO convoys: STANAG 2154 marking plus country-specific augmentation listed in Annex B to the STANAG. [7] [8]
During the Cold War with its high number of military exercises, the military was the main user of convoy rights. Today, catastrophes like large-scale flooding might bring a high number of flagged convoys to the roads. Large-scale evacuations for the disarming of World War II bombs are another common reason for non-governmental organization (NGO) unit movements under convoy rights.
In Norway, "convoy driving" (Norwegian : kolonnekjøring) is used during winter in case weather is too bad for vehicles to pass on their own. Convoy driving is initiated when the strong wind quickly fills the road with snow behind snowplows, particularly on mountain passes. [9] Only a limited number of vehicles are allowed for each convoy and convoy leader is obliged to decline vehicles not fit for the drive. [10] Storm convoys are prone to multiple-vehicle collision. [11] Convoy driving is used through Hardangervidda pass on road 7 during blizzards. [12] Convoy is sometimes used on road E134 at the highest and most exposed sections during bad weather. [13] On European route E6 through Saltfjellet pass convoy driving is often used when wind speed is over 15–20 m/s (fresh or strong gale) in winter conditions. During the winter of 1990 there was convoy driving for almost 500 hours at Saltfjellet [14]
The Kriegsmarine was the navy of Nazi Germany from 1935 to 1945. It superseded the Imperial German Navy of the German Empire (1871–1918) and the inter-war Reichsmarine (1919–1935) of the Weimar Republic. The Kriegsmarine was one of three official branches, along with the Heer and the Luftwaffe, of the Wehrmacht, the German armed forces from 1935 to 1945.
The Battle of the Atlantic, the longest continuous military campaign in World War II, ran from 1939 to the defeat of Nazi Germany in 1945, covering a major part of the naval history of World War II. At its core was the Allied naval blockade of Germany, announced the day after the declaration of war, and Germany's subsequent counter-blockade. The campaign peaked from mid-1940 through to the end of 1943.
PQ 17 was the code name for an Allied Arctic convoy during the Second World War. On 27 June 1942, the ships sailed from Hvalfjörður, Iceland, for the port of Arkhangelsk in the Soviet Union. The convoy was located by German forces on 1 July, after which it was shadowed continuously and attacked. The First Sea Lord Admiral Dudley Pound, acting on information that German surface units, including the German battleship Tirpitz, were moving to intercept, ordered the covering force built around the Allied battleships HMS Duke of York and the USS Washington away from the convoy and told the convoy to scatter. Because of vacillation by Oberkommando der Wehrmacht, the Tirpitz raid never materialised. The convoy was the first large joint Anglo-American naval operation under British command; in Churchill's view this encouraged a more careful approach to fleet movements.
The Arctic convoys of World War II were oceangoing convoys which sailed from the United Kingdom, Iceland, and North America to northern ports in the Soviet Union – primarily Arkhangelsk (Archangel) and Murmansk in Russia. There were 78 convoys between August 1941 and May 1945, sailing via several seas of the Atlantic and Arctic oceans, with periods with no sailings during several months in 1942, and in the summers of 1943 and 1944.
The first USS Twiggs (DD–127) was a Wickes-class destroyer in the United States Navy during World War I. She was named for Major Levi Twiggs. She was later transferred to the Royal Navy, as HMS Leamington and to the Soviet Navy as Zhguchy, before returning to Britain to star in the film The Gift Horse, which depicts the St. Nazaire Raid.
Operation Sportpalast, also known as Operation Nordmeer, was a German naval raid between 6 and 13 March 1942 against two of the Allied Arctic convoys of World War II as they passed through the Norwegian Sea. It was conducted by the battleship Tirpitz, three destroyers and eight submarines. The German ships were unable to locate either of the convoys but sank a merchant vessel that was sailing independently. The Allies attempted to intercept the German force, also without success.
Anti-submarine warfare is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations are typically carried out to protect friendly shipping and coastal facilities from submarine attacks and to overcome blockades.
The development of the steam ironclad firing explosive shells in the mid-19th century rendered sailing ship tactics obsolete.
HMS Onslow was an O-class destroyer of the Royal Navy. The O-class were intermediate destroyers, designed before the outbreak of the Second World War to meet likely demands for large number of destroyers. They had a main gun armament of four 4.7 in guns, and had a design speed of 36 kn. Onslow was ordered on 2 October 1939 and was built by John Brown & Company at their Clydebank, Glasgow shipyard, launching on 31 March 1941 and completing on 8 October 1941.
Convoy PQ 18 was an Arctic convoy of forty Allied freighters from Scotland and Iceland to Arkhangelsk in the Soviet Union in the war against Nazi Germany. The convoy departed Loch Ewe, Scotland on 2 September 1942, rendezvoused with more ships and escorts at Iceland and arrived at Arkhangelsk on 21 September. An exceptionally large number of escorts was provided by the Royal Navy in Operation EV, including the first escort carrier to accompany an Arctic convoy. Detailed information on German intentions was provided by the code breakers at Bletchley Park and elsewhere, through Ultra signals decrypts and eavesdropping on Luftwaffe wireless communications.
Newfoundland Escort Force (NEF) was a Second World War naval command created on 20 May 1941 as part of the Allied convoy system in the Battle of the Atlantic. Created in response to the movement of German U-boats into the western Atlantic Ocean, the Newfoundland Escort Force (NEF) was instituted to cover the convoy escort gap that existed between the local convoy escort in Canada and the United Kingdom. The Royal Canadian Navy provided the majority of naval vessels to the NEF along with its commander Commodore Leonard W. Murray, with units from the British, Norwegian, Polish, French and Dutch navies also assigned. The NEF was reconstituted as part of the Mid-Ocean Escort Force in 1942.
HMS Escapade was an E-class destroyer built for the Royal Navy in the early 1930s. Although assigned to the Home Fleet upon completion in 1934, the ship was attached to the Mediterranean Fleet in 1935–1936 during the Abyssinia Crisis. During the Spanish Civil War of 1936–1939 she spent considerable time in Spanish waters, enforcing the arms blockade imposed by Britain and France on both sides of the conflict. Escapade was assigned to convoy escort and anti-submarine patrol duties in the Western Approaches when World War II began in September 1939, but transferred back to the Home Fleet at the end of the year.
HMS Opportune was an O-class destroyer of the Royal Navy. She was ordered from John I. Thornycroft & Company, Woolston on 3 September 1939 for the 1st Emergency Flotilla. She was commissioned on 14 August 1942. She was the second Royal Navy ship borne Opportune.
Convoy PQ 15 was an Arctic convoy sent from Iceland by the Western Allies to aid the Soviet Union during the Second World War. The convoy sailed in late April 1942, reaching the Soviet northern ports after air attacks that sank three ships out of twenty-five.
Convoy PQ 14 was an Arctic convoy sent from Britain by the Western Allies to aid the Soviet Union during the Second World War. Convoys from Britain had been despatched since August 1941 and advantage had been taken of the perpetual darkness of the Arctic winter. German operations against the convoys had been muted due to the need to support Operation Barbarossa, confidence in imminent victory and the small size of the convoys. In late 1941 and early 1942 the Luftwaffe and Kriegsmarine had reinforced Norway with aircraft and ships.
At the beginning of World War II, the Royal Navy was the strongest navy in the world, with the largest number of warships built and with naval bases across the globe. It had over 15 battleships and battlecruisers, 7 aircraft carriers, 66 cruisers, 164 destroyers and 66 submarines. With a massive merchant navy, about a third of the world total, it also dominated shipping. The Royal Navy fought in every theatre from the Atlantic, Mediterranean, freezing Northern routes to Russia and the Pacific ocean.
Arctic naval operations of World War II were the World War II naval operations that took place in the Arctic Ocean, and can be considered part of the Battle of the Atlantic and/or of the European Theatre of World War II.
Convoy QP 10 was an Arctic convoy of World War II, consisting of empty merchant ships returning from the Soviet Union after delivering their cargo there. The convoy consisted of 16 merchant ships and an escort of nine warships. The convoy departed Murmansk on 10 April 1942 and arrived in Reykjavik on 21 April. The convoy was attacked by German U-boats and aircraft, resulting in the loss of four merchant ships. Another ship, Stone Street, was damaged by air attack and forced to turn back to the Kola Inlet. The convoy's escorts shot down six German planes and damaged another during the course of the voyage. Later, six merchant ships from Convoy PQ 14 joined QP 10.
The Western Approaches Tactical Unit (WATU) was a unit of the British Royal Navy created in January 1942 to develop and disseminate new tactics to counter German submarine attacks on trans-Atlantic shipping convoys. It was led by Captain Gilbert Roberts and was principally staffed by officers and ratings from the Women's Royal Naval Service (Wrens). Their primary tool for studying U-boat attacks and developing countermeasures was wargames. After the U-boat threat to merchant shipping was defeated, WATU continued to develop anti-submarine tactics for later stages of the war, including Operation Overlord and the Pacific War. WATU trained naval officers in its tactics by hosting week-long training courses in which the students played wargames. WATU formally ceased operations at the end of July 1945.
World War II was the first war where naval aviation took a major part in the hostilities. Aircraft carriers were used from the start of the war in Europe looking for German merchant raiders and escorting convoys. Offensive operations began with the Norwegian campaign where British carriers supported the fighting on land.
