page_title: Amphibious warfare
section_title: D-day
hierarchical_section_title: Amphibious warfare / Modern amphibious operations / Second World War / D-day
caption_attribution_description: English: The Mulberry artificial harbour off Arromanches in Normandy, September 1944. An aerial oblique photograph of the Mulberry Harbour off Arromanches. Artificial harbours were constructed along the beach shortly after D-Day so that armoured vehicles and heavy guns could be landed.
context_page_description: Amphibious warfare is a type of offensive military operation that today uses naval ships to project ground and air power onto a hostile or potentially hostile shore at a designated landing beach. Through history the operations were conducted using ship's boats as the primary method of delivering troops to shore. Since the Gallipoli Campaign, specialised watercraft were increasingly designed for landing troops, materiel and vehicles, including by landing craft and for insertion of commandos, by fast patrol boats, zodiacs and from mini-submersibles.
  The term amphibious first emerged in the United Kingdom and the United States during the 1930s with introduction of vehicles such as Vickers-Carden-Loyd Light Amphibious Tank or the Landing Vehicle Tracked.
  Amphibious warfare includes operations defined by their type, purpose, scale and means of execution. In the British Empire at the time these were called combined operations which were defined as "...operations where naval, military or air forces in any combination are co-operating with each other, working independently under their respective commanders, but with a common strategic object."
context_section_description: The most famous amphibious assault of the war, and of all time, was the Normandy Landings on 6 June 1944, in which British, Canadian, and US forces were landed at Utah, Omaha, Gold, Juno and Sword beaches in the largest amphibious operation in history.
  The organizational planning of the landing itself (Operation Neptune) was in the hands of Admiral Bertram Ramsay. It covered the landing of the troops and their re-supply. Many innovative elements were included in the operation to ensure its success.
  Operation Pluto was a scheme developed by Arthur Hartley, chief engineer with the Anglo-Iranian Oil Company, to construct an undersea oil pipeline under the English Channel between England and France to provide logistical support to the landed armies. Allied forces on the European continent required a tremendous amount of fuel. Pipelines were considered necessary to relieve dependence on oil tankers, which could be slowed by bad weather, were susceptible to German submarines, and were also needed in the Pacific War. Geoffrey William Lloyd, the Minister for Petroleum gained the support of Admiral Mountbatten, Chief of Combined Operations for the operation.
  Two types of pipeline were developed. The first type was the flexible HAIS pipe with a 3 inch (75 mm) diameter lead core, weighing around 55 long tons per nautical mile (30 t/km), was essentially a development by Siemens Brothers (in conjunction with the National Physical Laboratory) of their existing undersea telegraph cables, and known as HAIS (from Hartley-Anglo-Iranian-Siemens). The second type was a less flexible steel pipe of similar diameter, developed by engineers from the Iraq Petroleum Company and the Burmah Oil Company.
  In June 1942 the Post Office cable ship Iris laid lengths of both Siemens’ and Henleys’ cable in the Clyde. The pipeline was completely successful and PLUTO was formally brought into the plans for the invasion of Europe. The project was deemed "strategically important, tactically adventurous, and, from the industrial point of view, strenuous". After full-scale testing of an 83 km (45 nautical mile) HAIS pipe across the Bristol Channel between Swansea in Wales and Watermouth in North Devon, the first line to France was laid on 12 August 1944, over the 130 km (70 nautical miles) from Shanklin Chine on the Isle of Wight across the English Channel to Cherbourg. A further HAIS pipe and two HAMELs followed. As the fighting moved closer to Germany, 17 other lines (11 HAIS and 6 HAMEL) were laid from Dungeness to Ambleteuse in the Pas-de-Calais.
  In January 1945, 305 tonnes (300 long tons) of fuel was pumped to France per day, which increased tenfold to 3,048 tonnes (3,000 long tons) per day in March, and eventually to 4,000 tons (almost 1,000,000 Imperial gallons) per day. In total, over 781 000 m³ (equal to a cube with 92 metre long sides or over 172 million imperial gallons) of gasoline had been pumped to the Allied forces in Europe by VE day, providing a critical supply of fuel until a more permanent arrangement was made, although the pipeline remained in operation for some time after.
  Portable harbours were also prefabricated as temporary facilities to allow rapid offloading of cargo onto the beaches during the Allied invasion of Normandy. The Dieppe Raid of 1942 had shown that the Allies could not rely on being able to penetrate the Atlantic Wall to capture a port on the north French coast. The problem was that large ocean-going ships of the type needed to transport heavy and bulky cargoes and stores needed sufficient depth of water under their keels, together with dockside cranes, to off-load their cargo and this was not available except at the already heavily defended French harbours. Thus, the Mulberries were created to provide the port facilities necessary to offload the thousands of men and vehicles, and tons of supplies necessary to sustain Operation Overlord and the Battle of Normandy. The harbours were made up of all the elements one would expect of any harbour: breakwater, piers, roadways etc.
  At a meeting following the Dieppe Raid, Vice-Admir
caption: Overall aerial view of the Mulberry B harbour "Port Winston" in September 1944
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