Pipeline Under the Ocean
Shanklin Chine Isle of White fuel pipeline in WW2 Dungeness Siemens Calmens conundrum Operation Pluto 'Minor' HMS SANCROFT pipe laying ships in ww2
21 fuel pipelines between England and France safely delivered vital fuel to the Allied forces. The pipelines advanced as the front line moved east towards Germany. How this was achieved remains an extraordinary engineering achievement to this day.
PLUTO - Pipeline Under the Ocean.

21 Fuel Pipelines Under the English Channel to France in WW2.

Background

PLUTO, the WW2 Pipeline Under the Ocean (the English Channel really), was designed to supply fuel from storage tanks in southern England to the Allied armies in France, without which any territorial gains would soon be lost. This page tells the story of the planning, development, testing and installation of the 21 pipelines and their contribution to the war effort.

[Photo; In the main control room at Dungeness. Captain J F Hutchings, RN, Senior Naval Officer Commanding Force "PLUTO" explaining the workings of the control panel which monitored the amount of fuel passing through each pipe line to France. Captain Hutchings developed the PLUTO concept. © IWM (A 28818).]

A reliable supply of fuel for the advancing Allied forces, following the D-Day landings, was of the highest priority. Planners knew that the future invasion of Europe would be the largest amphibious landing in history and without adequate and reliable supplies of fuel, any advance would at best slow down, and at worst, grind to a halt. A loss of momentum could jeopardise the whole operation as German forces would have opportunity to regroup and counter-attack.

Conventional oil tankers and 'ship to shore' pipelines were in danger of cluttering up the beaches, obstructing the movement of men, armaments and materials and, in all circumstances, were subject to the vagaries of the weather and sea conditions. They were easy targets for the Luftwaffe. The idea of a pipeline under the English Channel was an innovative solution that stretched the boundaries of knowledge.

Oil storage facilities, located near the English Channel, were vulnerable to attack by the Luftwaffe. To reduce the risk of losses, a network of pipelines was an early priority and already under construction. The network was designed to carry fuel from less vulnerable storage and port facilities around Bristol and Liverpool to the English Channel. This network would later be linked to the planned pipeline at Shanklin on the Isle of Wight and Dungeness further to the west. (see map below). The terminals and pumping stations were heavily disguised as bungalows, gravel pits, garages and even an ice cream shop!

Plans & Preparation

The Combined Operations Experimental Establishment (COXE pronounced coxy) was involved in many diverse top-secret projects including the waterproofing of vehicles, the removal of underwater obstacles on landing beaches and the testing of landing craft under a variety of sea and beach conditions. To this formidable list was added the supply of petrol to France using underwater pipelines. All these challenges were borne out of a culture that encouraged bold and imaginative solutions to intractable problems. Such a culture was encouraged at the highest level when Churchill ordered Roger Keyes, the then Director of Combined Operations, and his successors, to think offensively when many were at the time rightly concerned with the defence of the country.

In the early part of 1942, Geoffrey Lloyd MP, who was in charge of the UK's fuel policy, met with Mountbatten, Chief of Combined Operations (CCO) and others to consider the fuel supply issue. There was no 'off the shelf' solution that did not invite the Luftwaffe to attack shore installations or slow pipe-laying and support vessels. Lloyd approached Sir William Fraser CBE Chairman of the Anglo-Iranian Petroleum Corporation. They picked up on an idea of Mr Hartley, the Chief Engineer of the Anglo-Iranian Oil Co., to use existing submarine cable technology, minus the core, as the basic building block of a petrol pipeline. Siemens Brothers & Co Ltd., of Woolwich, London, who were experienced in the design and manufacture of such cables, eagerly took up the challenge. Other design work was undertaken by Henlys, Pirelli, Johnson & Phillips, the National Physical Laboratory and the Post Office. It was a complex task and there were many failures arising from twists, kinks, bursts and collapse due to external water pressure and other powerful forces.

Design Specifications

Early designs envisaged the creation of a 2 inch bore pipe of hardened lead with 2 layers of 2 mm steel strip reinforced with galvanised steel wire. Sections were 'bench tested', a preliminary design specification was settled upon, and about 1100 yards were manufactured for 'field' testing. In May 1942, the pipe was laid across the Medway by the Post Office cable laying ship Alert and fuel was pumped successfully at a pressure of 600 lbs. per square inch. From observations and data collected, the programme of experimentation and modification continued, and by June of 1942, they were ready for deep water trials that were conducted in the Clyde estuary.

The Post Office cable ship Iris laid lengths of both Siemens and Henleys cable in the Clyde. Both pipelines were 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.

The Clyde trials showed that it was necessary to maintain an internal pressure of about one hundred pounds per square inch in the pipeline at all times, even during manufacture, to prevent distortion or collapse. It was also found that existing cable ships were not large enough and their loading and laying gear were not sufficiently powerful and robust for the task.

To tackle the inadequacy of the pipe handling and laying gear on board the cable ships, the Petroleum and Warfare Department turned to Johnson and Phillips for a solution. Mr G Whitehead re-designed the gear and a few merchant ships were converted to pipe-laying duties by stripping out their interiors, installing larger cylindrical steel tanks and fitting strengthened special hauling gear, sheaves and guides. These modifications took account of the fact that the minimum diameter needed to coil the pipe was ten-feet. The final equipment was fitted to HMS Holdfast.

The design, manufacture and testing of couplings to join sections of pipe together also presented complex problems. The aim was to achieve leak-free joints in a relatively straightforward process that was quick to complete and did not require highly qualified engineers and sophisticated equipment. Siemens were entrusted with the design, testing and manufacture of the couplings and the training of personnel. The expertise of lead-burners Frank Stone and his brothers, Albert and Ron, was called upon. They produced sample joints which were tested and refined until they passed all tests. They were awarded the contract for the manufacture of the joints and, working 18 hours per day for 2 years, made 500 joints at Siemens and 800 at Calmens, who had also been sub-contracted to manufacture some of the pipelines.

[Map courtesy of Google Map Data 2017.]

Each length of pipe was sealed at both ends and pressurised during the manufacturing process using 'copper bursting discs'. Within the coupling, the two pipe ends were only an inch or so apart and when the full operating pressure was applied the discs burst open allowing the free flow of petrol.

The complexities and commercial scale of the operation needed specialised knowledge in many disciplines, and suitably qualified people were drawn in as advisers and experts. One such was John Augustus Oriel, Chief Chemist of Shell Petroleum Co., Ltd., of London, who was a Fellow of the Institute of Chemistry GBI. Despite suffering from impaired vision, as a result of a gassing incident in the 1st World War, he made a substantial contribution to the PLUTO project.

Hundreds of miles of pipeline were needed and there were concerns over the supply of lead and the time available for manufacture. Two senior engineers (Hammick & Ellis) working on the project, had experience of laying 3" steel pipelines. They recalled that these were also flexible when laid in long lengths. This was welcome news and a parallel project was set up to find a second solution using steel pipes.

For security reasons, the two distinct systems were known as HAIS, a flexible multi-layered lead-based pipe and HAMEL a steel pipe. The former took the initials from Mr Hartley the inventor, Anglo/Iranian his employer, and Siemen the designers & manufactures, while the latter was derived from Mr Henry Alexander Hammick, Chief Engineer of the Iraq Petroleum Company Oil and Mr Ellis, Chief Engineer of the Burmah Oil Company. It was essential in war time to use terminology that conveyed nothing to the enemy. Furthermore, the use of the words pipe and pipeline was forbidden, all concerned with the project being encouraged to think of cables rather than pipes.

Both systems had to be capable of laying down their pipes on the sea bed in a single, continuous, fast procedure. The HAIS pipe would be coiled on board the cable laying vessel and fed out as the vessel progressed across the Channel and the HAMEL pipe would be coiled around huge drums towed behind a tug-like vessel and fed out as they drum rolled along.

The final specification of the HAIS pipeline was for a flexible pipe comprising an inner lead pipe of 3 inches diameter, two layers of prepared paper tape, 1 layer of bitumen prepared cotton tape, 4 layers of mild steel tape, jute bedding, steel armour wires and an outermost layer of jute servings. Each mile of pipe used 24 tons of lead, 7.5 tons of steel tape and 15 tons of steel armour wire and smaller amounts of lighter materials. The external diameter of the pipe was 4.5 inches.

Detailed specification; lead tube internal bore 3.05 ins, minimum thickness 0.175 ins coated with petroleum residue compound, two layers of 10 mm prepared tape two ins wide, one layer of bitumen prepared cotton tape 2.25 ins wide applied with slight overlap, four layers of unvarnished cold rolled mild steel strip 2 ins wide by .022 ins thick, coating of petroleum residue compound, one serving of tarred jute yarn, 57 galvanised mild steel wires each 0.192 ins and separately compounded, coating of compound, two servings of tarred jute yarn compound between layers and overall and finally a coating of whitewash. The outside diameter was about 4.5 ins, maximum bursting pressure was 4,350 lbs/sq in, weight per mile approximately 47 tons - 54.25 tons when filled with pressurised water.

Pipe-Laying Operations

With the specification settled, a large scale trial was set up. For this, the cable laying ship 'London' was taken into service as HMS Holdfast under the command of Commander Treby-Heale OBE RNR. Its task was to run a pipeline between the Queen's Dock in Swansea and Watermouth, near Ilfracombe, some 45 miles away. Two specially fitted LCTs ran 2000 yards of the pipeline from each shore - the one at Swansea connected to a pumping station and the other to receiving tanks at Watermouth. The free ends were buoyed and a few days later, on December 27th 1942, the Holdfast recovered the Swansea end, joined it up to the main pipeline on board (HAIS pipes coiled on large drums), and steamed at 4 to 5 knots towards Watermouth laying the pipeline as she went.

[Photo; General view of the rubberised HAIS pipe being relayed from the hold to stern. © IWM (A 28807).]

The importance of this trial was manifest in the list of those monitoring its progress - Mr Hartley and Mr Tombs of Anglo-Iranian Oil, Mr Colby of Iraq Petroleum, Mr Betson of the Post Office, Commander Hardy of the Admiralty and Mr Whitehead of Johnson and Phillips, who had designed the pipe handling equipment.

Some setbacks followed. It took much longer than expected to effect a good joint, the pipeline was damaged, and a tanker dragged her anchor and severed the line. It was 100 days before pumping began at a rate of 1500 gallons per hour. It was a modest beginning but would eventually lead to 1,000,000 gallons per day being pumped across the channel.

Production of the 3" pipe started at Woolwich in September 1943 and a number of lengths had been completed a year later, one of which was 40 miles long and weighing 2,200 tons. Many regarded PLUTO as yet another wild fantasy of C.O.H.Q. Concerns were alleviated to some extent by the concurrent use of 'Tombola', a conventional tanker with the ability to pump oil to the shore for storage. This was set up at Port-en-Bessin and at Ste. Honorine two miles further to the west and was fully operational by June 14 1944. [Photos below courtesy of the US National Archives and the US Military History Institute.]

Photos l to r; 1. Operation Pluto 'Minor' initially pumped fuel from tankers a mile or so off-shore. 2. When Port en Bessin fell to the Allies, fuel was pumped directly from berthed tankers. 3. From the harbour two six inch lines, with booster pumps, carried motor vehicle and aviation fuel to the US tank farm at Mont-Cauvin, near Etreham, for British and American forces. 4. In addition to the two lines from Port en Bessin there were two from Sainte Honorine des Pertes. They joined up at Mont Cauvin where German prisoners filled jerry-cans for use in the field. 5. The main line from Port en Bessin was routed alongside the D6 road to Escures passed the area where the British/Commonwealth Bayeux cemetery now lies. 6. Steel can still be seen in the western harbour wall today, and possibly some pipes in the harbour, at low-tide.

By the time the two HAIS flexible pipelines and the two HAMEL steel pipelines to Cherbourg were pumping petrol, the Allied armies were moving west towards Paris and Belgium. 11 new HAIS pipelines and 6 HAMEL pipelines were laid in a swept channel two miles wide between Dungeness and Ambleteuse near Boulogne to shorten the supply route.

In all, about 500 miles of pipeline were laid across the English Channel in an average laying time, over the 30 mile stretch, of about 5 hours. In January 1945, the system delivered a disappointing 300 tons but, by March, this had increased to 3000 tons and later still to 4000 tons. This amounted to over 1,000,000 gallons per day, giving a total of 172,000,000 gallons delivered up to the end of hostilities. During the operation to lay the cables, an HQ ship, several cable ships, tugs, trawlers and barges were employed on this specialised work - a total of 34 vessels with 600 men and officers under Captain Hutchings.

The 21 pipelines were vital arteries, which enabled the Allied Air Fleets and Land Forces to maintain the momentum needed to secure a victory. Moreover, PLUTO obviated the need for fleets of tankers, sparing their crews the ordeal of concentrated enemy attacks in congested waters.

Major Vessels Used

Pipe Layers

Empire Ridley (HMS Latimer)

A standard British 'Empire' ship, type Y1 of 6,838 gross tonnage and 10,000 tons deadweight. Built by Lithgow Limited of Port Glasgow (No. 939). Launched 21/8/41 and completed in Nov 41. Taken over by the British Admiralty and converted to a cable laying vessel for Operation PLUTO in 1943 and renamed HMS Latimer. Returned to Ministry of War Transport in late summer 1945. Sold to Norway in 1949 and underwent conversion in Italy and re-sold to new Italian owners and renamed Acheo. Scrapped in Sakai, Japan in 1964.

Empire Baffin (HMS Sancroft0

Standard British 'Empire' ship type Y1 of 6,978 gross tonnage and 10,000 tons deadweight. Built by Lithgow Limited of Port Glasgow (No. 957). Launched late August 1941 and completed in October 1941. Taken over by the British Admiralty and converted to a cable laying vessel for Operation PLUTO in 1943 and renamed HMS Sancroft. Returned to the Ministry of War Transport in 1946 and later that year was renamed S/S Clintonia for the Stag Line of North Shields. In 1960 she was S/S Aspis of the Faros Shipping Company of London. Scrapped in Yokosuka, Japan in 1963.

HMS Holdfast

HMS Holdfast was the first HAIS cable laying ship. She was converted from the Dundee, Perth & London Shipping Company's coastal passenger ship 'London'. She was built in 1941 by Hawthorns & Co Ltd of Leith, Scotland and was of 1499 gross tonnage. Conversion commenced in the summer of 1942 and was completed later the same year.

[Photo; HMS Holdfast football team 1943/44 with names o thumbnail below.]

HMS Algerian

A ship of 2315 gross tonnage converted for the purpose of pipe laying. She was formally the S/S Algerian of Messrs Ellerman & Papayanni Lines Ltd.

All the above conversions were carried out by Green and Silley Weir Ltd,. London and all cable handling machinery was by Messrs Johnson & Phillips.

Inshore Craft

Inshore craft comprised the coastal motor barges Brittanic, Oceanic and Runic and the twin screw barges Goldbell and Goldrift.

Hopper Barge

W24 was a 725 gross tonnage dockyard hopper barge which became HMS Persepone when taken over by the Admiralty to undertake experimental work on the HAMEL steel pipes. She was converted at Portsmouth in 1943 when a cable drum of 48 feet diameter was positioned in her hold and mounted on trunnions on the main deck. In operation steel pipe was fed through the open hopper doors in the bottom of the vessel. She was the forerunner of the floating 'CONUN' drums which, when employed in the Force, became known as HMS Conundrum!

Conun Drums

Following successful trials with a large prototype in early 1944, five 'conuns' were commissioned to a modified design. The new drums, of 30 feet diameter, were fabricated in Scunthorpe, erected in Tilbury Docks and launched into the Thames. Each of the conuns weighed in at 250 tons and had a combined capacity to carry up to 60 nautical miles of HAMEL pipes.

Tugs

HMRT Bustler - 3200 indicated horsepower ahead.

HMRT Marauder - 3000 indicated horsepower ahead.

HMRT Danube V a smaller craft astern of the two above to facilitate steering of the tow.

The Salvage Fleet

S/S Empire Ridley as per PLUTO Fleet

S/S Empire Taw as per HMS Holdfast of the PLUTO Fleet.

S/S Empire Tignes was a tanker of 407 gross tonnage built in 1943 for the German Navy. Prize 1945. It was converted to recover HAMEL steel pipes by Marine Contractors of Southampton. It was sold in 1949 to Risdon, Beazley & Co and became Topmast No 15. Sold to Dutch buyers in 1953 and in 1959 became an inland waterways tank barge.

S/S Wrangler was a Mark III Tank Landing Craft converted by Marine Contractors Ltd. to recover HAMEL steel pipes and to undertake general salvage work

M/V Redeemer was an ex Navy wooden hulled motor fishing vessel built in 1940. It served as tender to the recovery ships.

When the PLUTO project was finally disbanded in 1945, its Senior Naval Officer Commanding Force PLUTO, Captain J F Hutchings, wrote a letter of appreciation and good wishes to his men. This particular copy was received by Charlie Bradshaw, who served aboard HMS Latimer for a couple of years or so. Charlie passed away in 2016 and always spoke fondly of his time on the Latimer.

Land Based Operations UK

In order l - r; 1. Beachside bungalows were used as pumping stations... 2. This photo before work started half way through the conversion. 3. Following camouflage. 4. A Mather and Platt pump in one of the bungalows. 5. The pumping control room. 6. PLUTO pump station installation team (see correspondence below).Most of the innovative work was on the design, development and testing of the submerged pipelines. However, this does not diminish the scale or importance of the land based preparatory work, particularly in southern England. The engineers, scientists and Army personnel provided storage tanks, a pipeline distribution network and pumping stations, where the pipelines entered the English Channel. The 1943/44 photos, below, of the pumping station at Dungeness, on the Kent coast, were supplied by Gordon Stirling.

The army, in the guise of the Royal Engineers, Royal Army Service Corp, Pioneer Corp and the Royal Canadian Engineers were all involved in laying the pipelines over land.

Land Based Operations Mainland Europe

1. Western Map including Cherbourg & Port en Bressin.

2. Front cover of booklet.

3. Recruitment & Training. Tendring is a district in NE Essex, clearly of some significance.

4. Arrival at Port en Bessin in Normandy. Confined for a while, 1st recce under battle conditions. Place names mentioned - Marquise, Lier, Aalst, Glendringen and Cleve (Kleve?)

5. The daily grind - places mentioned Arromanches, Antwerp and Materborn.

6. HQ - places mentioned - Bayeux, Linth, Aalst & Materborn.

7. Celebrations at Eeklo, Belguim in the summer of 1945. Job done, hostilities over, home and demob imminent. The wedding bells are a symbol of Captain Mould's marriage.

8. Eastern map including Calais, Antwerp and Aalst.

Further Reading

On This Website;

PLUTO in Fawley,

PLUTO - the Salvage Operation

PLUTO Pipe Manufacture

There are around 300 books listed on our 'Combined Operations Books' page. They, or any other books you know about, can be purchased on-line from the Advanced Book Exchange (ABE). Their search banner link, on our 'Books' page, checks the shelves of thousands of book shops world-wide. Just type in, or copy and paste the title of your choice, or use the 'keyword' box for book suggestions. There's no obligation to buy, no registration and no passwords.

Other Sources;

Stewart & Lloyd Film of their manufacturing process - https://www.youtube.com/watch?v=FIYS_9EI5j0

PLUTO - World War 11's Best-Kept Secret by Bob Knight, Harry Smith & Barry Barnett. Published in 1998 by Bexley Council. Softback, 34 pages with many illustrations about the involvement of The Callender Cable Co.

PLUTO - Pipe-line under the Ocean by Adrian Searle. Publisher Shanklin Chine, 12 Pomona Road, Shanklin, Isle of Wight PO37 6PF. ISBN 0 9525876 0 (Description of book. To many in WWII, it seemed a preposterous idea - an undersea pipeline laid across the bed of the Channel to carry fuel to the Normandy beaches. It was carried out in absolute secrecy and, according to Eisenhower, it was "second in daring only to the artificial 'Mulberry' Harbours.' The extraordinary project, & the millions of gallons of fuel it carried, helped to ensure that the Allied armies could break out after D-Day. 126pp, photos, ills, maps).

National Archive, Kew, London

Some records on PLUTO are available to be viewed (personal callers or paid researchers only - NOT available on line). You may find others by visiting their Online Catalogue. Copies of documents can be ordered on line.

Acknowledgements

This account is based on information provided by Capt. FA Roughton MBE, who was involved in the laying down of the pipelines and their salvage after the war. Capt Roughton died on the 11th March 2013 at the age of 100. We are grateful to him for the legacy he left behind about PLUTO, for the benefit of future generations.

The technical data about, and images of, the HAIS flexible pipeline are from an article written by Mr EA Beavis, BSc, AIMEE published in Seimens Brothers Engineering Bulletin No 224 dated January 1946.

Places to Visit

1) The Shanklin Chine on the Isle of Wight is a beautiful place in its own right but for those with a special interest in the 'Pipeline Under the Ocean' it harbours something of a surprise. Here is an extract from the Shanklin Chine website.

"During the war the Chine was taken over and used as an assault course by the Commandos whose HQ was at Upper Chine School. 40 Royal Marine Commando trained there in preparation for the Dieppe raid in 1942. A plaque to their memory was dedicated on 6th June 1984, the 40th Anniversary of D-Day.

PLUTO also ran through the Chine and there are still 65 yards of the pipe remaining. PLUTO, one of the great secret successes of the war, was the idea of Lord Mountbatten. During the Normandy invasion in 1944, forked pipelines from the Chine and Sandown carried petrol 65 miles under the Channel to Cherbourg, the first taking only ten hours to lay. The pipelines delivered 56,000 gallons a day until the Allies advanced so far that the line was transferred to Dungeness in Kent. There a million gallons daily were piped to Boulogne and eventually as far as the Rhine. A cross-section of the actual pipe can be seen in the Heritage Centre, together with a video of the story of PLUTO and other exhibits.

2) On the other side of the channel at Port en Bessinyou can still see remnants of PLUTO. Nigel Stewart, an official Normandy Guide writes; "The remnants can be seen at low tide in the left-hand western harbour of Port-en-Bessin. Drive into the harbour and walk down to the causeway on the front. The remnants are there, easily visible. For those travelling independently the Port of Bessin is due north of Bayeux."

3) For information about PLUTO in the Epsom area of Surrey visit this excellent local history website.

4) For information about PLUTO in Greatstone on the east Kent coast between Folkestone and Rye, and about one mile from the cinque port of New Romney on the Romney Marsh, visit http://www.greatstone.net/history/pluto.htm

(2/04) PLUTO - Pipeline Under the Ocean. I've just found out that my late grandfather, Norman Kellington, was involved in the design of PLUTO. He was chief engineer at Orthostyle, Brigg Road Works, Ashby, Scunthorpe. He worked there under Admiralty orders to design the floating pipe laying buoys for PLUTO which were manufactured in Scunthorpe and assembled in Tilbury. Much of this information comes from a recently discovered press cutting from the Scunthorpe Star dated May 1977.