Operation Pluto

• 1. Introduction

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  Operation Pluto began with a question in early April 1942. Lord Louis Mountbatten, then Vice-Admiral and Chief of Combined Operations, approached Geoffrey Lloyd, the Secretary for Petroleum. He asked whether an oil pipeline could be laid under the English Channel. Mountbatten was planning the Allied invasion of German-occupied Europe, and petroleum supply was his central worry. The British War Office had estimated that petrol, oil, and lubricants would account for sixty per cent or more of all expedition supplies by weight. Coastal tankers were the obvious alternative, but they were vulnerable to air attack and bad weather. They also depended on shore-based storage that enemy forces could destroy. When Lloyd consulted his advisors, including the geologist George Martin Lees, one conclusion was unanimous. Laying a pipeline across the Channel was infeasible using any known method. That consensus did not survive the week. The engineer who changed it heard about the proposal almost by accident, and the devices he inspired would eventually stretch under both the Strait of Dover and the Solent.

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• 2. An Accidental Engineer

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  Clifford Hartley heard the proposal discussed as impossible during a routine visit to the Petroleum Warfare Department. Hartley was the Chief Engineer of Anglo-Iranian Oil Company. He was not persuaded by the verdict. Anglo-Iranian had run a three-inch pipeline through the hilly terrain of Iran at 1,500 psi. That line delivered 100,000 imperial gallons per day, the equivalent of more than twenty thousand jerricans. On the 15th of April 1942, Hartley presented his proposal: a pipeline modelled on a submarine telegraph cable, stripped of its communications core but armoured to hold internal pressure. A cable-layer ship would deploy it. Multiple lines could be laid in parallel. Running at high pressure, a single pipeline could carry aviation spirit and then switch to diesel without the two fuels mixing.

  The chairman of Anglo-Iranian, Sir William Fraser, agreed to fund the trials. Fraser was also petroleum advisor to the War Office. Henry Wright, the managing director of Siemens Brothers, provided industrial manufacturing capability. The resulting cable was named Hais, from the initials of Hartley, Anglo-Iranian, and Siemens. Its two-inch inner pipe was made from extruded lead. Around that went layers of asphalt, paper impregnated with vinylite resin, and steel tape for strength and flexibility. Fifty galvanised steel wires formed the outermost protective sheath. The pipe could deliver 3,500 imperial gallons per day at 500 psi and withstand underwater pressure of 1,950 psi.

  A 120-yard prototype was laid across the River Medway by a Post Office cable ship on the 10th of May 1942. It failed after two days of pumping. Lead had extruded through gaps in the steel tape. Engineers increased the steel tape from two layers to four, and a second test across the Firth of Clyde in June succeeded. Full-scale production started on the 14th of August 1942 using steel from the Corby Steelworks.

  In December 1942, a thirty-mile trial length was laid across the Bristol Channel in rough weather at five knots. Shore ends were connected at Swansea and Ilfracombe. During the trial, two German 500-pound bombs fell on Swansea only one hundred feet from the cable. A ship's anchor later dragged the pipe, but the cable ship Holdfast found and repaired the damage. Pumping ran continuously at 1,500 psi, delivering 56,000 imperial gallons of fuel per day. The pipeline was judged ready.

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• 3. The Hamel Alternative

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  Lead was in short supply. Bernard J. Ellis, the chief engineer of the Burmah Oil Company, proposed a mild steel pipe as a backup system. His design used walls 0.212 inches thick and was fabricated in thirty-foot segments by J & E Hall, a firm better known as a manufacturer of refrigeration equipment. Ellis designed a special broaching tool to remove the metal swarf left by flash welding. He partnered with H. A. Hammick, the chief engineer of Iraq Petroleum Company, and their surnames gave the pipe its name: Hamel.

  Hamel pipe was too stiff to coil inside a ship's hold. The Petroleum Warfare Department's solution was a giant buoyant steel drum. The drum was sixty feet long and forty feet in diameter. It was known as a Conundrum. Six were built at £30,000 apiece, named one through six. Tests in the Froude tank at the National Physical Laboratory confirmed that Conundrums could be towed at speed without yawing. Each loaded Conundrum held ninety miles of pipe and displaced 1,600 long tons. An Admiralty hopper barge, 200 feet long and 35 feet wide, was converted to carry one Conundrum. She was renamed HMS Persephone.

  On the 4th of June 1943, a one-mile trial lay succeeded. Because the estimated service life of Hamel pipe was only about six weeks, fluorescein dye was added to the fuel. Patrol aircraft could then spot leaks from the air. After the war, Ellis successfully asserted his claim to be recognised as Hamel's sole inventor, despite having shared the development with Hammick.

  With two working pipeline types in hand, the next challenge was building the facilities to pump fuel through them without alerting German intelligence.

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• 4. Concealment and Deception

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  In the spring of 1943, the Petroleum Warfare Department selected two pumping station sites. One was at Sandown on the Isle of Wight; the other was at Dungeness on the Kent coast. Construction happened at night. Equipment arrived under tarpaulins. The pumping stations and storage tanks were disguised as villas, seaside cottages, old forts, and amusement parks. The initials of the Petroleum Warfare Department were banned from all correspondence and packages. Locations were erased from maps. Lorry drivers delivering supplies had to telephone from public phone booths for directions.

  Each pumping station held thirty diesel-powered reciprocating pumps with a daily capacity of 180 long tons each. Four large Byron Jackson Company electric centrifugal pumps added 3,500 long tons per day, operating at 400,000 imperial gallons at 1,500 psi. Both stations drew from the Avonmouth-Thames pipeline. A seventy-mile branch line connected Dungeness to its eastern terminal at Walton-on-Thames. A twenty-two-mile link connected Sandown to Fawley Refinery. All pipeline connections were completed by March 1944.

  The deception went further at Dover. As part of Operation Fortitude, a fake oil dock was constructed there. The architect Basil Spence designed it. Built from camouflaged scaffolding, fibreboard, and old sewage pipe, the facility covered three acres. It included fake versions of pipelines, storage tanks, jetties, vehicle parks, and antiaircraft emplacements. Wind machines generated dust clouds to simulate activity. At night a smoke screen obscured the site. German aircraft were permitted to overfly the facility, but only above 33,000 feet, where high-resolution photography was not possible. King George VI inspected the fake facility. General Dwight D. Eisenhower and General Sir Bernard Montgomery spoke to the apparent workers.

  The original plan called for the port of Cherbourg to be captured by D+8 and the Bambi pipeline to be fully operational by D+75. Events on the ground would not cooperate.

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• 5. Bambi's Failures

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  The port of Cherbourg was supposed to fall within eight days of D-Day. The discovery of an additional German division in the area in May pushed that estimate back to D+18. In the event, Cherbourg was not captured until the 27th of June, D+21. Due to extensive demolitions, the first petroleum tanker did not discharge there until the 25th of July. While Allied forces waited, fuel came through the small port of Port-en-Bessin using Tombola ship-to-shore pipelines and coastal tankers. The Tombola lines broke repeatedly. By the 28th of July, sixteen coastal tankers were laid up for repairs at Hamble-le-Rice.

  HMS Latimer laid the first Hais pipeline across to Cherbourg in just ten hours on the 12th of August 1944. An escorting destroyer then caught the pipeline with its anchor and destroyed it beyond repair. HMS Sancroft tried two days later. Its effort failed when pipe became wrapped around the propeller of the support vessel HMS Algerian. An attempt to lay Hamel pipe on the 27th of August had to stop because tons of barnacles had attached to the bottom of HMS Conundrum 1, preventing it from rotating. The barnacles were scraped off and another attempt was made, but the pipe broke about twenty-nine nautical miles out.

  On the 22nd of September, a Hais cable finally worked, delivering 56,000 imperial gallons per day. A Hamel cable followed on the 29th of September. Then on the 3rd of October, pressure was increased from 50 to 70 bar. Both pipelines failed simultaneously. The Hais gave out at a faulty coupling; the Hamel struck a sharp edge on the ocean floor. Operation Bambi was shut down the following day. Total fuel transferred was about 3,300 long tons. Sir Donald Banks, one of Lloyd's original advisors, captured the problem in plain terms. He wrote that the technique of cable laying had been mastered, but the naval parties were not yet sufficiently versed in connecting the shore ends or in repairing the undersea leaks that those faulty concluding operations caused.

  The Dumbo project, meanwhile, was about to get its chance, running from Dungeness to a target that had already shifted from the original plan.

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• 6. Dumbo's Reach

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  Boulogne fell on the 22nd of September, and its port opened on the 22nd of October. The original Dumbo plan had called for a connection to Ambleteuse, but the beach there was heavily mined. Engineers redirected to Boulogne instead, twenty-three nautical miles across the Strait of Dover. HMS Sancroft laid a Hais pipeline. It began pumping on the 26th of October and stayed in action until the end of the war. Hamel pipe proved more troublesome, but after trial and error it was laid with sections of Hais at each end to manage the difficult shore connections. Because Boulogne had poor railway facilities, the pipeline was extended to Calais, where better rail connections could move the fuel inland. That extension was completed in November 1944.

  By December, nine three-inch and two two-inch Hamel pipelines were in place, along with four three-inch and two two-inch Hais cable pipelines, totalling seventeen. Dumbo was delivering 1,300 long tons of petrol per day. Not one of the Hais cable pipelines broke. Mean time between repairs for the Hamel lines ranged from 52 to 112 days, with 68 days as the average. Plans to pump aviation spirit through the pipelines were discarded; the lines could not run at the intended pressure and carried only petrol.

  As the fighting moved into Germany, Dumbo was connected to an inland pipeline system extending from Boulogne to Antwerp, Eindhoven, and eventually Emmerich. On the 15th of March 1945, Dumbo surpassed its target of one million imperial gallons per day. By the 3rd of April, the lines were delivering 4,500 long tons a day to the Rhine. New lines continued to be added; the last was laid on the 24th of May. The system was shut down on the 7th of August 1945 to save manpower. By that date the pipelines had carried 180 million imperial gallons of petrol.

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• 7. Legacy and Reckoning

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  Operation Pluto was officially disbanded on the 31st of August 1945. The Petroleum Warfare Department was wound up on the 31st of March 1946. Total cost was reckoned at £4,428,000. Roughly 5.4 million long tons of petroleum products were delivered to the Allied Expeditionary Force in North West Europe. Operation Pluto's pipelines contributed about 370,000 long tons of that total, or eight per cent. The Royal Commission on Awards to Inventors issued tax-free payments. Hartley received £9,000; Ellis received £5,000. M. K. Purvis, who designed the Conundrum, received £85. A. E. Price, who designed the wedge gripping device for anchoring the pipe near shore, received £250.

  The operation's records were sent to the Public Record Office, where they remained sealed for the next thirty years. No post-war use of the technology was contemplated. Recovery crews then worked from September 1946 to October 1949, pulling more than 85 per cent of the pipeline back to the surface. Of the original 23,000 long tons of lead, 22,000 long tons were recovered. Of 5,500 long tons of steel, 3,300 long tons came up. Crews also retrieved 75,000 imperial gallons of petrol still inside the pipes. The total value of the salvaged lead and steel was estimated at £400,000.

  The debate over what Pluto had actually accomplished ran through the official histories. Samuel Eliot Morison, the American naval historian, judged that the pipelines proved very useful for supplying the Allied armies as they advanced into Germany. Michael Postan, the civil official historian, called the operation strategically important, tactically adventurous, and industrially strenuous. Winston Churchill spoke about Operation Pluto on the 24th of May 1945. He called it a wholly British achievement and a piece of amphibious engineering skill of which the country could be proud. The counter-case came from Derek Payton-Smith. Writing in the civil official history of oil, he argued that Pluto contributed nothing to Allied supplies at the most critical moment, when no regular oil ports were available on the continent. Major-General Sir Frederick Morgan, who had headed the COSSAC staff overseeing Pluto, agreed that Bambi was not worthwhile, though he praised Dumbo.

  One physical trace of the operation survives with particular incongruity: the former pumping station at Sandown on the Isle of Wight is now a miniature golf facility.

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