Operation Pluto

• 1. Strategic Origins And Planning

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  In early April 1942, Lord Louis Mountbatten approached Geoffrey Lloyd with a desperate question. Could an oil pipeline be laid across the English Channel? The British War Office estimated that petrol, oil, and lubricants would account for more than 60 per cent of the weight of supplies required by the expeditionary forces. They needed a way to move fuel without relying on coastal tankers. These ships were hindered by bad weather and subject to air attack. They also needed vulnerable storage tanks ashore to offload their cargo. A new kind of pipeline was required that could be rapidly deployed. Two types were developed, named Hais and Hamel after their inventors. Two pipeline systems were laid, each connected by camouflaged pumping stations to the Avonmouth-Thames pipeline. Lloyd consulted his expert advisors: Brigadier Sir Donald Banks, Sir William Fraser, and George Martin Lees. At the time, submarine pipelines were in use in ports and over short distances. No pipeline had ever been laid across such a great distance or under the currents and tidal conditions found in the English Channel. Moreover, to minimise interference by the enemy and the effect of the tides, the entire pipeline would have to be laid in a single night. They regarded the proposal as infeasible using any known method of construction of pipelines 12 inches or more in diameter.

• 2. Engineering Innovations In Pipeline Design

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  Clifford Hartley pitched his proposal for a continuous length of pipeline similar to a submarine communications cable. It would lack the core and insulation but include armour to withstand internal pressure. The inner pipe carrying petroleum was made from extruded lead. This was surrounded by a layer of asphalt and paper impregnated with vinylite resin. Steel tape was wound around this to give it strength and flexibility. Around this was a layer of jute tape and asphalt-impregnated paper. Finally, it was covered by a protective layer of fifty galvanised steel wires. A 2-inch prototype was laid across the River Medway on the 10th of May 1942. A pumping test then carried out using pumps borrowed from the Manchester Ship Canal Company failed after two days. The problem was caused by extrusion of the lead through gaps in the steel tape. The amount of steel tape was increased from two to four layers. Siemens Brothers developed the cable based on their existing undersea telegraph cable. It was known as Hais, from Hartley-Anglo-Iranian-Siemens. Full-scale production started on the 14th of August 1942 using steel from the Corby Steelworks. A second supplier, Henleys, was brought in to increase manufacturing capacity. Of the 50 miles of Hais cable produced for the operation, 30 miles were made by firms in the United Kingdom while 20 miles was manufactured in the United States.

• 3. Operational Deployment Across The Channel

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  The first Hais pipeline was laid by HMS Latimer in just ten hours on the 12th of August 1944. The pipeline failed when an escorting destroyer caught it with its anchor and damaged it beyond repair. A second effort was made by HMS Sancroft two days later. This too failed when the pipe became wrapped around the propeller of the support ship, HMS Algerian. An attempt to lay Hamel pipe instead failed on the 27th of August when tons of barnacles had attached themselves to the bottom of HMS Conundrum 1. The barnacles were scraped off, but another attempt broke about 5 miles out. Finally, on the 22nd of September a Hais cable was laid that worked, delivering 60,000 gallons per day. This was followed on the 29th of September by the successful installation of a Hamel cable by HMS Conundrum 2. However, on the 3rd of October when pressure increased from 100 psi to 200 psi, both pipelines failed. The Hais line suffered a faulty coupling, and the Hamel encountered a sharp edge on the ocean floor. Operation Bambi was terminated the following day. Only about 800,000 gallons of fuel had been transferred.

• 4. Bambi Project Failures And Adjustments

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  The port of Cherbourg was captured on the 27th of June, D+21, due to extensive damage. The first POL tanker did not discharge there until the 25th of July, D+49. In the meantime, fuel was supplied through the small port of Port-en-Bessin by coastal tankers. Ocean-going tankers used two Tombola lines at Port-en-Bessin for the British and five at Sainte-Honorine-des-Pertes for the Americans. The Tombola lines had a tendency to break, and the Chants fared poorly in rough weather. By the 28th of July sixteen of them were laid up for repairs at a special tanker repair facility established at Hamble-le-Rice. Consideration was given to cancelling Pluto, but under the circumstances it was decided to proceed. Time was wasted in deciding whether to terminate the line inside or outside the harbour. Eventually the latter was chosen. Sir Donald Banks wrote that cable laying technique had been mastered but they were not yet sufficiently versed in connecting shore ends. They also lacked experience in effecting repairs to undersea leaks caused fairly close inshore through faulty concluding operations. Operation Bambi delivered just 800,000 gallons between the 22nd of September when the first pipeline became operational and the 4th of October when it was terminated.

• 5. Dumbo System Success And Expansion

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  A Hais pipeline was laid by HMS Sancroft which commenced pumping on the 26th of October. It remained in action until the end of the war. Lines ran to a beach in the outer harbour of Boulogne, 15 miles distant across the Strait of Dover. This involved a longer distance and more difficult approach than originally planned because the beach at Ambleteuse was heavily mined. The ends of the cable were dropped just offshore and picked up by barges for connection to the shore. By December, nine 3-inch and two 2-inch Hamel pipelines and four 3-inch and two 2-inch Hais cable pipelines had been laid. A total of 17 pipelines provided 600,000 gallons of petrol per day. Not one of the Hais cable pipelines broke. The mean time between repairs of the Hamel pipelines varied between 52 and 112 days with 68 days being the average. As fighting moved on to Germany, Dumbo connected to an inland pipeline system extended from Boulogne to Antwerp, Eindhoven and ultimately Emmerich. Dumbo surpassed its target of 400,000 gallons per day on the 15th of March 1945. By the 3rd of April the Dumbo lines delivered 1 million gallons a day to the Rhine.

• 6. Deception Tactics And Camouflage Efforts

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  As part of Operation Overlord deception known as Operation Fortitude, a fake oil dock was created at Dover. Architect Basil Spence designed it using camouflaged scaffolding, fibreboard and old sewage pipe. The facility spanned 1,000 feet and included fake versions of pipelines, storage tanks, jetties, vehicle parks and antiaircraft emplacements. Wind machines were used to create clouds of dust to simulate activity. The site was guarded by military police. At night it was obscured by a smoke screen. German aircraft were allowed to overfly the facility but only above 10,000 feet where high-resolution imagery was not possible. The fake facility was inspected by King George VI. Supreme Allied Commander General Dwight D. Eisenhower and his ground forces commander General Sir Bernard Montgomery spoke to workers. Pumping stations and storage tanks were camouflaged to look like villas, seaside cottages, old forts, amusement parks and other innocuous features. Strict instructions issued that neither Petroleum Warfare Department nor its initials should appear on any letter or package. Locations were erased from maps. Lorry drivers conducting deliveries had to phone from a public phone booth for instructions.

• 7. Post-War Salvage And Historical Legacy

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  After the war more than 85 per cent of the pipeline was salvaged and subsequently scrapped. This occurred during September 1946 to October 1949 using ships named Empire Ridley, Empire Taw, Empire Tigness, Wrangler and Redeemer. In all 2,000 tons of original 2,300 tons of lead and 1,500 tons of original 1,700 tons of steel were recovered. Along with 1 million gallons of petrol still in pipelines. Value of scrap lead and steel well exceeded costs of recovery. Total value estimated at £400,000. The system closed down to save manpower on the 7th of August by which time pipelines carried 100 million gallons of petrol. Operation Pluto officially disbanded on the 31st of August. Petroleum Warfare Department wound up on the 31st of March 1946. Tilbury plant transferred to Admiralty. All remaining stores went to Ministry of Supply. No post-war use of technology contemplated so records sent to Public Record Office where they remained sealed for next thirty years. Royal Commission on Awards to Inventors awarded tax-free payments of £9,000 to Hartley and £5,000 to Ellis.