The Allied mechanised armies and expeditionary air forces had a voracious appetite for fuel.
11 million jerry cans were produced in readiness and initial fuel stocks of 14,00 tons would be loaded on the invasion fleet but moving large tankers loaded with petrol into the English Channel whilst still in range of German combat aviation and submarines would not be advisable. It became obvious during D Day planning that the only means of keeping up with demand at an acceptable level of risk would be some form of pipeline. Undersea pipelines for fuel were not revolutionary but these were carefully constructed and not subject to enemy fire.
Work started on the ‘fuel problem’ in 1942 and a number of schemes were considered but they centred on two concepts, a ship to shore system for the early stages of the operation followed up with a series of high volume undersea pipelines. The pipeline system was known as PLUTO, Pipeline Under the Ocean, or more correctly, Pipeline Underwater Transport of Oil and the ship to shore system, TOMBOLA.
Industry was co-opted and the design team included staff from the Anglo Iranian Oil Corporation (now BP), Siemens Brothers, Pirelli, Shell, Burmah Oil and the Post Office. The design effort included the shore handling facilities, the pipes themselves and the means to lay them.
Two pipeline designs were to be used, HAIS and HAMEL.
HAIS (Hartley/Anglo-Iranian/Siemens) was based on an underwater power cable with the core copper conductors removed. 3 inches in diameter it weighed approximately 55 tons per nautical mile, although it was flexible the immense quantities of lead required were impractical. An alternative was developed, HAMEL.
HAMEL (Hammick/Ellis) was a much less flexible 3 inch steel pipeline, it was much cheaper to produce than HAIS but very difficult to coil. The two could be joined however and after testing it was decided to use HAMEL for the majority of the length and jointed to short lengths of HAIS where flexibility was needed.
Converted cable laying ships were used in trials but these proved to be inadequate inadequate, a telegraph cable being completely different to handle than a large diameter PLUTO cable. Modifications were made to HMS Holdfast to enable the HAIS pipelines to be laid and a large number of tugs and other vessels were used, including two additional pipeline laying ships.
Laying HAMEL pipeline was a particularly difficult problem but a novel system was found to offer great potential. Wrapping the pipeline around huge drums called Conun-Drums allowed continuous sections to be unspooled whilst afloat.
Final trials were completed in December 1942 between Swansea and Ilfracombe using 2″ HAIS pipeline. They were a great success and prompted the decision to increase the diameter of the pipeline, the trial pipeline was also used for supplying Devon and Cornwall. From then, it was full steam ahead with manufacture of the pipeline, pumping stations and storage facilities. Fuel would be pumped from the ports of Liverpool and Bristol to the transmission points on the south coast using a network of pipelines constructed at night to avoid detection by German aircraft. In order to disguise the on shore installations, pumping equipment was disguised as houses and even ice cream shops.
For transfer from ship to shore a system called TOMBOLA was devised that used a floating pontoon and series of connecting pipelines to connect a tanker floating offshore to the shore. The pipelines were relatively short and connected using threaded sleeves. Wooden pontoons, flexible pipes and buoys were used at both ends. The tanker would haul up the pipe, connect and commence pumping. An alternative systems using rigid floating pipes called AMETHEA was developed but not used.
Following the liberation of the Port-en-Bessin to the West of Arromanches by a combined force of 47 Commando Royal Marines and 4 SAS Brigade the quayside would be used to offload small coastal tankers. By D+9 fuel would be pumped to storage tanks and jerrycan filling equipment at Mt Cauvin, near Etreham, 3km inland from the port.
The pipelines from Port-en-Bessin would be joined by two 6″ TOMBOLA pipelines bought ashore at Saint Honorine-des-Pertes, 5km from Port-en-Bassin.
The plan for PLUTO required two routes to be established; 4 lines between the Isle of Wight (Bambi) and Cherbourg and 17 lines between Dungeness (Dumbo) and Boulogne.
The extensive damage at Cherbourg meant the pipelines could not be installed until D+36. By the end of the operation 6 HAMEL and 11 HAIS pipelines were terminated at Cherbourg. This route only delivered 3,300 tons of fuel before it was closed down on the 4th of October, it was perhaps a lot of effort for not a lot of delivered fuel. Meanwhile, the TOMBOLA system and Port en Bessin continued to be used to great effect, greatly exceeding expectations. Cherbourg was also receiving tanker deliveries soon after.
Operations then concentrated on the shorter route between Dungeness and Boulogne which delivered vastly more, by VE day over 170 million gallons had been delivered.
Eisenhower described PLUTO as;
As the security situation improved the Allies were able to bring large tankers into the area and made extensive and increasing use of French, Belgian and Dutch ports. The first tanker to dock at Cherbourg was the SS Empire Traveller, arriving on the 24th July.
Cherbourg would be the most important but Ostend and Antwerp would also play a major role. Antwerp was captured almost intact and had considerable receiving and storage facilities.
After clearance activities were completed the first tanker was received at Antwerp on December 3rd 1944.