Pipelines Under The Ocean

From Global Energy Monitor
This article is part of the Global Fossil Infrastructure Tracker, a project of Global Energy Monitor.

Pipelines Under The Ocean, also known as the PLUTO Pipeline, or Operation Pluto, is a retired oil pipeline network that spans the English Channel between England and France.


One leg of the network runs from Shanklin Chine, England to Cherbourg, France. Another runs from Dungeness, England to Ambleteuse, France.

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Project Details

  • Operator:
  • Current capacity:
  • Length: 1,255.3 km / 780 mi
  • Status: Retired
  • Start Year:


The PLUTO network was a Second World War operation by British engineers, oil companies, and the British Armed Forces; to construct undersea oil pipelines under the English Channel between England and France in support of Operation Overlord, the Allied invasion of Normandy in June 1944. PLUTO originally stood for 'Pipe-Line Underwater Transportation of Oil'.

The scheme was developed by Arthur Hartley, chief engineer with the Anglo-Iranian Oil Company. 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. In 1942, Geoffrey William Lloyd, the Secretary for Petroleum, met Admiral Mountbatten, Chief of Combined Operations, whose area this was, and then the Chairman of Anglo-Iranian. Hartley's idea of using adapted submarine telephone cable was adopted.

The Battle of Normandy was won without a drop of fuel being delivered via the Pluto cross-channel pipelines. Only eight per cent of the fuel delivered to the Allied forces in North-West Europe between D-Day and VE Day was via those pipelines; the rest being by tanker, either in bulk or in cans, or by airlift.


Two types of pipeline were used in the network. The first was a flexible HAIS pipe with a 3 inches (76 mm) diameter lead core, weighing around 55 long tons per nautical mile (30 t/km), 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).

However, the amount of lead required to produce enough HAIS pipe was prohibitively expensive. As a result, it was decided that an alternative would be needed that made use of cheaper and more readily available materials such as mild steel.

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, known as HAMEL from the contraction of the two chief engineers, H. A. Hammick and B. J. Ellis. It was discovered in testing that the HAMEL pipe was best used with final sections of HAIS pipe at each end. Because of the rigidity of the HAMEL pipe, a special apparatus code-named The CONUN drum was developed to lay the pipe.

The first prototypes were tested in May 1942 across the River Medway, and in June in deep water across the Firth of Clyde using vertical triple ram pumps manufactured by Tangye Pumps, Cornwell Works in Birmingham, with an operating capability of 1,500 pounds per square inch (100 bar) at 3,000 rpm, before going into production with the basic steel pipe for HAMEL supplied by Stewarts & Lloyds of Corby, manufacturing of the final system was carried out by Siemens Brothers at Woolwich, Henley's at North Woolwich, Callender's at Erith, and Standard Telephones and Cables at Greenwich. Because of capacity limitations in the UK, some HAIS pipeline was also manufactured in the United States.

After full-scale testing of an 83 kilometres (45 nautical miles) of 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 kilometres (70 nmi) from Shanklin Chine on the Isle of Wight across the English Channel to Cherbourg. This, however, failed when an escorting destroyer caught the line with its anchor. A further HAIS pipe and two HAMELs followed, but one of these again failed before coming into operation. As Sir Donald Banks wrote, ‘The technique of cable laying had been mastered but we were not yet sufficiently versed in the practice of connecting the shore ends, nor in effecting repairs to the undersea leaks which were caused fairly close inshore through these faulty concluding operations.’ It was not until 18 September that a HAIS cable was finally commissioned; it came into operation on the 22nd September, approximately three months late. On 29 September a HAMEL pipe also became operational. However, on 3 October when the pressure was increased to augment the amount of fuel pumped, both failed and Operation BAMBI (pipeline route to Cherbourg) was abandoned. 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. The success of these lines was, however, limited with only 8% of the fuel delivered between D-Day and VE Day being via them.

The initial performance of the PLUTO pipeline was disappointing. During the period from June to October 1944, it carried on average only 150 barrels per day, just 0.16% of the Allies total consumption during the same period.

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 petrol 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. The official history states that 'PLUTO contributed nothing to Allied supplies at a time that would have been most valuable.'

While the pipeline itself is no longer in use, many of the buildings that were constructed or used to disguise it remain in operation today, especially on the Isle of Wight, where the former pumping station at Sandown is currently in use as a mini-golf facility.

In 1994, the Midland Bank (now part of HSBC) sponsored a black-and-white film which contained a remarkable amount of historical archive film showing the entire history and construction of the Pluto Project, the HAIS pipe, and the Conundrum reels. It mentions the codewords 'Bambi', 'Watson', 'Dumbo Near', 'Dumbo Far', and other terminal names. It shows how the HAIS pipe was constructed and increased in diameter from about 2" to the later 3" operational size. When the landing site for the invasion was switched from Calais to Normandy, the pipeline needed to be increased from its original length to around 70 miles (110 km), and the film tells of how the American pipeline industry became involved in producing the extra amount of HAIS pipe.

The film can be seen in a small heritage museum at Shanklin Chine on the Isle of Wight, one of the Pluto terminals, where there are also a lot of other memorabilia, books and photographs. One of the original pumps used on the Isle of Wight has now been restored to its original position in the fort at Sandown, now a part of the Isle of Wight Zoo, and visitors can get a good 'feel' for what it must have been like to work there. Entrance is inside the zoo. Another pump is preserved in the Bembridge Heritage Centre. Brenzett Museum, Romney Marsh, houses a small permanent display related to Pluto at Dungeness.

A film titled Operation Pluto, produced by the former Ministry of Fuel and Power, is held in the British Film Institute archives. This film was part of a loop of films that was shown at the East Carlton Park steel heritage centre in Northamptonshire for many years.

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Wikipedia also has an article on the Pipelines Under The Ocean ([1]). This article may use content from the Wikipedia article under the terms of the Creative Commons Attribution-ShareAlike 3.0 Unported License].