By Bill Burns & Stewart Ash
A large part of
the borough of Greenwich is currently being re-developed to provide much-needed
housing and new commercial premises. This includes the regeneration of several
old industrial sites along the river front. One such ‘brown field’ development
is the Faraday Works, in the north-west corner of the old Siemens Brothers
factory.
The factory was established in 1863 by Charles William Siemens
(1823-83), on land leased from the Bowater Estate, and the site is still
situated on the south bank of the River Thames, at the border of Charlton and
Woolwich. It is bounded on the other three sides by Eastmoor Street, Warspite
Road, and the Woolwich Road. Charles was born Carl Wilhelm Siemens on 4 April
1823 in Berlin, and came to England in March 1848 to set up a branch of Siemens
& Halske. This company had been founded in Berlin by his elder brother Ernst
Werner Siemens (1816-92) and Johann Georg Halske (1814-90). By 1858, Carl
Wilhelm had registered the Siemens & Halske Agency in London, providing
engineering consultancy to the emerging telegraph market. Its clients included
the British Government, for both the terrestrial electrical telegraph and the
pioneering submarine telegraph cables markets. At the same time, another
brother, Karl Heinrich Von Siemens (1829-1906), set up a Siemens & Halske
factory in St Petersburg to sell telegraph equipment and cables to the Russians.
On 19 March 1859, Carl Wilhelm became a naturalized British subject under a
warrant granted by Queen Victoria, changing his name to Charles William Siemens.
This was in preparation for his marriage to Anne Gordon (1821-1901) on 23 July
that year. She was the sister of Lewis Brodie Gordon (1815-76), Professor of
Civil Engineering and Mechanics at Glasgow University. In 1865, a rift developed
between William Siemens and Johann Halske over the submarine telegraph cable
market, which Halske considered too risky, so they went their separate ways.
Halske retained a large equity stake in the London company, but it was
re-registered as Siemens Brothers. In 1869, Karl Hendrich came to join William
in London, and he too would later become a naturalised British citizen.
Artist’s
Impression of the Original Siemens Brothers Site in 1863, by E Neale c 1927
Siemens Brothers prospered and the site expanded to 35 acres (14 Hectares),
employing around 10,000 people at its peak, second only to the Royal Arsenal in
the size of the site and its number of employees. Despite its strong German
links, which would result in confiscation of share capital and internment and/or
deportation of many German national employees during both World Wars, Siemens
Brothers was responsible for several major technical developments that assisted
the allies in both WWI and WWII. In the First World War, these included field
telephone systems and trench cable, but perhaps the most significant development
was the ruggedised light bulbs for the Aldis and OL signalling lamps, used by
the Royal Navy and Army respectively in both wars. In the Second World War, the
demand for telecommunication cable was again high because of bomb damage caused
by German air-raids, but significant military projects included the ‘Clyde
Loop’, that protected and kept the mouth of the River Clyde free of mines, and
the High-Speed Motor Uniselector used in the revolutionary RADAR system, then
known as ‘Chain Home’. Siemens also produced the extremely robust light bulbs
for the Churchill Tank, without which it would have been inoperable, due to the
massive vibrations produced by its engine and drive system. However, perhaps the
most audacious and ingenious of these products was the rapid development and
manufacture, in complete secrecy, of the H.A.I.S. Cable for Operation PLUTO
(Pipe Line Under The Ocean).
The story of PLUTO begins in early April 1942, when
Lord Louis Mountbatten (1900-79), the Queen’s second cousin, and at that time
Chief of Combined Operations, put a proposition to Geoffrey Lloyd (1902-84), the
Conservative MP for Birmingham Ladywood, at that time Secretary for Petroleum
and head of the Petroleum Warfare Department of the Ministry of Fuel and Power.
Mountbatten’s proposal was that if a military campaign into Europe against the
Nazis was to be successful, then there would need to be a pipeline across the
English Channel to provide petrol, oil and lubricants in bulk to support the
armed forces. Lloyd put this concept to the experts in his department and their
consultants who had, prior to the outbreak of war, been working on pipelines
across the Bristol Channel, the River Mersey and the Thames. Their advice was
that tidal and weather conditions in the English Channel, together with the risk
of enemy action, would make it impossible to implement using any currently known
land or sea construction method, which required pipes of 6” (inches) or more in
diameter. However, the problem reached the ears of Arthur Clifford Hartley
(1889-1960), Chief Engineer of the Anglo-Iranian Oil Co Ltd. A few years
earlier, his company had solved the problem of transportation of oil, over a
very hilly route, by the development of a 3” pipe working at 1,500 pounds per
square inch (psi) [103.4 bar]. Hartley recognised that such a pipe could deliver
100,000 gallons of fuel per day, the equivalent of 25,000 ‘Jerrycans’, the
method used to refuel vehicles in the field. So, on 15 April 1942, Hartley made
a suggestion to his Chairman, Sir William Fraser (1888-1970), who was also
Honorary Petroleum Advisor to the War Office, that such a line could make a
significant contribution to this problem and that if multiple lines were built
it would have the major advantage of not having all their eggs in one basket.
One obvious problem was that the pipeline would need to be laid quickly to
overcome the tides and currents, and ideally it should be laid in one operation
without joints at sea. This would also have the advantage of limiting the risk
of enemy action disrupting the operation. Hartley thought it might be possible
to use submarine cable technology to contrive a cable without a core that could
be deployed by a cableship. Fraser encouraged Hartley to develop his idea
further and promised him his full support, so the next day Hartley called on the
Managing Director of Siemens Brothers, Dr Henry Robert Wright (1879-1951).
Wright thought that the concept was viable and immediately arranged for his
Woolwich factory to design and make a 200-yard (183m) test length which could
withstand an internal pressure of 500lb psi (34.47bar). It was manufactured from
materials that were already available in stock and consisted of a 2” bore tube
of hardened lead, reinforced with two layers of 10mm steel tapes, and
over-armoured with galvanised steel wires. Production was completed within a
week and a rigorous static testing regimen then commenced, which included strain
and pressure tests to failure. The results were promising and demonstrated that
a much higher working pressure of up to 750psi (51.7bar) could be achieved.
The
design of the cable was based on Siemens Brothers’ experience of developing
gas-filled power cables, combined with their vast experience in making and
laying submarine cables. The design concept was intended to deliver 30,000
gallons a day over the 20 nautical mile (nm) span from Dover to Calais. Just
fifteen days after the initial contact with Dr Wright, Geoffrey Lloyd and the
Services Chiefs involved in Operation PLUTO visited the factory to see the test
cable coiled on board the Post Office cableship HMTS Alert (2) anchored off the
Woolwich Works in the River Thames. The party included Lieutenant-General
Bernard Law Montgomery (1887-1976). So pleased were they with the progress that
Lloyd requested a short sample of the test cable that he could take to show the
Prime Minister, Winston Churchill (1874-1965).
Geoffrey Lloyd and the Service
Chiefs. Including General Montgomery on the far left
Shortly after this visit
instructions came from 10 Downing Street to proceed with the project with all
speed.
The Post Office, the Admiralty, Combined Operations, the War Office and
Anglo-Iranian were called together at the Petroleum Division HQ to arrange the
manufacture of further lengths and prepare a complete test programme.
Anglo-Iranian undertook, as agents of the Petroleum Division, to develop, order,
progress and supervise the whole of the pipe, pipe joints, pumping
installations, etc. that would be required, and Siemens Brothers, without
waiting for official orders or priorities, quickly produced more cable. Secrecy
from the enemy was paramount and the cable was given the codename ‘H.A.I.S.’ an
acronym derived from Hartley, Anglo-Iranian & Siemens.
One of the most important
features of this project was the necessity for all discussions, development and
manufacture to be carried out in absolute secrecy, as if information were to
have leaked concerning the nature of what was being planned, the enemy would
have taken any risk to prevent the cable being completed, or to destroy it when
it was being laid in the English Channel. Elaborate precautions were put in
place; one section of the Siemens Works was isolated and special passes were
issued to every person, whether senior management or factory worker, who was
required to enter the area. In addition, the staff engaged in the work were
called into the factory library, where the Works Manager informed them not of
the purpose to which the new cable was to be put, but of the fact that they were
to be engaged in a job vital to the war effort. Therefore, it was of the utmost
importance for them not to talk to anyone, either inside the Works or outside,
concerning the work on which they were engaged. Everyone whom it became
necessary to allow to enter the secure area was compelled to sign a statement
signifying their complete understanding of the requirements of the Official
Secrets Act. It appears that Government security officers were brought in to
test the strength of the systems in place, and they made repeated but
unsuccessful attempts to enter the restricted areas of the Works. After the war,
Siemens was formally congratulated upon the efficiency of the precautions and
safeguards that it had put in place and operated throughout the project.
The
handling trial that had taken place on 1 May 1942 showed that the test sample
could be coiled into a tank, loaded onto a cableship, and discharged back into
the factory without impairing its performance. The next step was to manufacture
a much longer length, deploy it, and test it in situ.
The next section of test
cable to be manufactured was 1,100 yards (1,006m) in length. On 10 May 1942, it
was laid by the Alert (2) in a loop off Chatham, in the Medway. The ends were
brought ashore to pumps that had been borrowed from the Manchester Ship Canal
Co, and pumping tests at 600psi (41.37bar) were commenced. However, after two
days faults occurred in the cable structure, so the cable was recovered and the
defective sections examined by the Post Office, Siemens Brothers and W T Henley
& Co. Under normal circumstances, Henley’s would have been a major competitor of
Siemens Brothers but it was at Siemens’ suggestion that Henley’s was invited to
join the project to provide additional manufacturing capability, as its factory
at Gravesend was adjacent to the River Thames, which would facilitate transfer
of the cable to cableships. This collaboration between commercial competitors
would continue throughout Operation PLUTO.
The cable failure mechanism was
quickly identified as the extrusion of the lead through gaps in the helical
steel strengthening tapes, due to the two layers of tape being directly one
above the other in certain places along the cable. To resolve the problem the
combined resources of the Siemens and Henley’s Research and Design departments,
together with the Post Office and the National Physical Laboratory, both of
which had been brought in to assist, were mobilised. The result was that a new
specification was drawn up within two days of the failure mechanism being
identified. Lengths of this design were then ordered from both cable making
companies. The new design comprised a central lead-tin-antimony pipe, 2” in
diameter, wrapped with two layers of paper tape, one of cotton, four layers of
steel tape (right hand lay), jute, helically lapped longitudinal steel wires
(left hand lay) and further layers of jute covered with whitewash. The opposite
lays of the tapes and the armour wires were designed to balance each other,
making the cable torsionally neutral, so that it would not twist under handling
or the influence of internal pressure. This design was calculated to allow for
an internal pressure of 1,250 psi (86 bar).
Telescoped Section of the Final 2”
H.A.I.S. Cable
In June 1942, test lengths of both firms' manufacture were laid
by the Post Office ship HMTS Iris (2) in water of similar depth to the English
Channel in the Clyde estuary. Siemens' cable was the first to be deployed; it
was laid over the bow with the ship steaming ahead and with the central tube
containing air at atmospheric pressure. After the cable was recovered from a
depth of about 33 fathoms (61m), it was pressurised to 90psi (6.2 bar), and it
appeared that the cable was leaking, as after the cable had been filled with
water, the applied test pressure would not remain steady. In addition, water
appeared on the outside of the cable, seeping through the outer jute serving at
several places along the cable length. These locations were stripped down to the
lead tube, where it was found to have been pressed in on itself into a kidney
shape. The reason for this was that the tensile load applied to the cable, both
on the forward drum engine and when passing over the bow sheave, had deformed
the circular lead tube into an oval, and the external hydrostatic pressure of
the sea had then further crushed the deformed tube Because of this, some sea
water was found to have been trapped in the space formed between the lead pipe
and its steel tape protection. Under application of the test pressure, the lead
pipe had begun to return to its circular form, and this pushed the trapped water
through the outer armouring and serving, giving the impression of leaks.
Cross
Section of Deformed Trials Cable
Due to the increasing urgency of the project,
it was decided to go ahead with the lay of the Henley’s cable in parallel with
this investigation into the assumed failure of the Siemens cable. It was again
laid from the bow of the Iris (2), but this time with the ship going astern to
simulate the less demanding over-the-stern laying conditions. In addition, the
Henley’s cable was laid while filled with water pressurised to 100 psi (6.89
bar) to balance the external hydrostatic pressure. The complete success of this
test lay, combined with the confirmation that the Siemens cable had not failed,
was encouraging. The Siemens cable had undergone more severe conditions during
its lay than the Henley’s cable, and in so doing had proved that the design was
capable of withstanding much rougher handling. This gave the PLUTO team the
confidence to make the decision to manufacture six operational lengths of 26
nautical miles (48.23km), plus an additional length for a full-scale trial in
the Bristol Channel, where conditions of tide and depth of water could be found
that were more severe than those that would be encountered in the English
Channel.
When going into full production, it was necessary to evaluate the
differences in the method of manufacture of lead tubes used by the cable making
companies. Siemens believed that its technique, using a vertical press that
involving a longitudinal seam, while entirely satisfactory for extruding lead
sheath over ordinary cables, might need some development to make it satisfactory
for making the central tube for the H.A.I.S. Cable. Rather than run the slight
risk of delay, it was agreed to use lead tube made in presses, a method which
avoided a longitudinal seam. Pirelli’s lead sheath, made in a continuous
extrusion machine, was tested and proved satisfactory but before it could be
adopted Pirelli’s works were taken out of operation by enemy action. As Henley’s
lead tube, made in its ‘Judge’ straight-though presses, had been proved
suitable, this type of press provided all the lead pipe used until the
manufacturing capacity of further cable companies had to be brought in to
produce the large quantities of cable eventually required. Lead tubes made by
Pirelli’s continuous presses and by vertical presses (including those with
longitudinal seams) both in the UK and the USA, were later used with complete
success.
Full scale production on this 2” cable commenced at the Woolwich Works
on 14 August 1942, and the first completed 26nm (48.25km) length for the Bristol
Channel trial, which had an overall diameter of 3” and weighed approximately
1,050 tons (1,067 tonnes), was ready for loading by 30 October. It had been
quickly identified that no existing cableship could handle and deploy this
extremely heavy cable, and that a vessel large enough to carry it would have too
great a draft to get close enough inshore to land the cable ends. Therefore, the
Admiralty and the Ministry of War Transport made available the S.S. London, a
coaster of 1,500 tons. She was fitted out to lay the H.A.I.S. Cable under the
direction of the Director of Naval Construction, and renamed H.M.S. Holdfast.
She was equipped with Johnson & Phillips cable gear, lent by the Post Office,
and fitted with large cable tanks and specialist bow and stern sheaves. Siemens
suggested to the authorities that Commander Henry Treby-Heale (1879-1966) should
be made available for the laying operations and perhaps given command. He had,
until recently, been in command of the company’s cableship Faraday (2), but she
had been destroyed by enemy action off Milford Haven on 26 March 1941.
Treby-Heale survived the attack and had then been seconded to the Royal Naval
Reserve (RNR). He was an ideal choice, as he had great experience in the laying
of heavy submarine cables, and so Siemens’ suggestion was readily accepted.
HMS
Holdfast
This just left the problem of landing the shore ends. It was concluded
that these needed to be landed by smaller vessels and a quick coupling or joint
was required to join the main cable to the shore end cable.
Shore Ends & Cable
Couplings
Two satisfactory types of armoured joint were developed. The first
consisted of a conventional submarine cable laid-in ‘splice’, and the second
comprised a mechanical coupling assembly. The splicing method was used for
making up shore-end lengths and for repair work on long sections in storage
tanks or on cableships, when in dock. Altogether, some forty splices were made
by Siemens' jointers, but the job proved to be too time consuming and demanded
too great a skill-set to be practicable when laying under fire, or for emergency
repair operations; therefore, a mechanical coupling was essential.
The design of
such a coupling was a complex issue, and initial designs were prepared by the
National Physical Laboratory, the Admiralty, the Petroleum Warfare Department
and Siemens. After due consideration the Siemens design was adopted, and the
company became the sole supplier of all couplings used in connection with
Operation PLUTO.
The H.A.I.S. Cable Coupling
Each coupling was a complete
pressure termination for a single cable end and could be fitted in about two
hours by a skilled technician. Two couplings could then be brought together for
a straight-through connection and assembly could be completed in about 30
minutes. Couplings were fitted to each cable end on the ship, on shore ends, and
on spare sections for replacement or repairs. Meeting the requirement to quickly
connect the H.A.I.S. Cable was greatly improved by using the couplings instead
of the conventional in-line splice. The coupling design included bursting discs
of thin copper, which were incorporated in the joint to hold the water pressure
of up to 200psi (13.8 bar) that was used when laying the cable. Once the full
length was assembled these discs could then be burst by increasing the internal
water pressure, allowing flow through the completed pipeline.
Static tests were
continued on the 2” cables at the makers’ factories, and pressures in excess of
3,000psi (207 bar) were maintained for several months. Throughout the autumn of
1942, the Chiefs of Combined Operations conducted tests with cable on drums at
the experimental establishment at Westward Ho! in an endeavour to find ways of
handling the shore ends with craft which could be operated at the beaches. The
most promising method devised was to mount two cable drums with 1,000 yds.
(915m) of cable on horizontal axles in a landing craft (type LCT 326) designed
for landing armoured vehicles, with a view to paying the cable out over the bow
ramp, which was lowered with the craft going astern. This method was used as
part of the full-scale trial in December 1942.
The Bristol Channel Trial
With
all the necessary building blocks in place, a full-scale rehearsal of Operation
PLUTO took place on 29 December 1942, when a 30nm length of the H.A.I.S. Cable
was laid across the Bristol Channel, and the shore-end cables were to landed
from LCTs at Ilfracombe and Swansea. Although the main cable was laid
successfully at 5 knots by HMS Holdfast, under the command of Henry Treby-Heale
RNR, great difficulty was experienced in laying the shore ends, owing to the
lack of manoeuvrability of the LCTs when going astern with heavy cable over the
bow. Further development work would be required before the trail cable could be
completed.
As a result of a conference convened in January 1943 at Combined
Operations Headquarters to evaluate the rehearsal, it was agreed to adopt an
alternative method of landing the shore ends. This would employ the technique
used by submarine cable suppliers of coiling sufficient cable horizontally in
the hold of a self-propelled barge, specially fitted for paying out cable over
the stern through hand-controlled compressor gear. Although this involved
allotting precious Thames barges and their crews solely to this task, they were
made available, and the shore ends for the trial system were completed by the
end of March 1943.
The National Oil Refineries at Swansea, the Royal Engineers
(RE), and the Royal Army Service Corps (RASC) specially trained Bulk Petroleum
Companies had meanwhile erected a pumping station on the sea wall at Queens Dock
and connected it to their petrol tanks. The Royal Engineers, working with
Combined Operations and the RASC, had, with the help of the Petroleum Board,
erected a receiving terminal with tanks, pumps and loading racks in Watermouth
Bay near Ilfracombe. After satisfactorily testing with water, the first petrol
ever to be pumped through such a long sea line reached Watermouth on 4 April
1943. Geoffrey Lloyd was there to witness the first petrol arrive and a few days
later he took a sample to the Prime Minister.
It had always been the intention
that the vulnerability of the cable to bombing or depth charges, and the
possibilities of needing repairs should it be dragged by a ship's anchor, would
be evaluated. However, a German air raid on Swansea proved that the cable was
not damaged by a bomb that exploded within 100 ft (30.5m) of it. Also, during a
gale, a ship at the Mumbles anchorage dragged the cable with her anchor. H.M.S.
Holdfast was deployed and had no difficulty in locating the cable, cutting out
the damaged portion and completing the repair with a new length of H.A.I.S.
Cable.
In order to prove the reliability of the cable and pumps, and to train
the RE and RASC personnel who would be responsible for the operation, pumping
continued day and night. Initially the system was operated at the design
pressure of 750psi (51.7 bar) but later this was increased to 1,500 psi (103.5
bar). At this pressure, 56,000 gallons were pumped from Swansea to Watermouth
each day and distributed by the Petroleum Board around Devon and Cornwall. The
Hamel Pipe Before continuing the story of the H.A.I.S. Cable, it should be noted
that, early in its development, an alternative approach was introduced and
worked on in parallel. On behalf of the Petroleum Division, a Mr. Ellis and Mr.
Hammick were dealing with the H.A.I.S. Cable programme, and when they saw that
the cable was extremely stiff in short lengths but flexible and easily
manageable in long lengths, they suggested that a steel pipe could also be used
for PLUTO, as they had seen samples of small diameter pipes that were also
flexible when handled in long lengths in the oilfields.
With the assistance of
Stewart & Lloyd, J. & E. Hall of Dartford, and A. I. Welding, they quickly
proved that a 3” steel pipe with sufficient wall thickness to handle the
necessary pump pressure could be bent round a wheel of 30ft (9.1m). diameter and
pulled off again, remaining relatively straight without kinking, and sections
could be flash welded together to provide any required length. However, with
this bending diameter, it could not be handled like cable and stored in a
cableship’s tanks. One reason for this was that the coiling process results in a
complete twist being induced into each turn. Although this twist is removed
while uncoiling during laying, the steel pipe would not tolerate this treatment.
Mr. Ellis, therefore, suggested the use of a large wheel mounted on trunnions on
the deck of a Hopper Barge, with its lower portion protruding into the sea
through the hopper doors. An alternative approach, also adopted, was a huge
floating drum like a gigantic cotton reel, capable of carrying any quantity of
pipe likely to be required.
Model tests of the floating drum concept were
carried out at the National Physical Laboratory’s tank at Froude in Worcester.
These tests confirmed that such a vessel could be towed at sufficient speed
without yawing. This floating drum (vessel) was named HMS Conundrum, or ‘Conun’
as it became known. Preliminary work proved that the pipe could be laid up on
the drum and pulled off without kinking. The sections could be welded together
with absolute reliability; so long lengths could be carried and laid by either
the wheel and barge or the Conun system. Although there was no previous
experience as to how a bare steel pipe would lie and behave on the seabed, it
was calculated that it would have at least a six-week operational life. As the
H.A.I.S. Cable was as yet unproven, and there was significant concern as to
whether there would be sufficient supplies of lead available to complete the
H.A.I.S. programme and meet the operational targets, having a complementary
method, even if it was short lived, was considered desirable, and so it was
decided to proceed with this approach. This pipe was given the codename ‘Hamel’
after its inventors, Hammick and Ellis. A factory at Tilbury was set up to weld,
store and wind Hamel Pipe. A Hopper Barge was converted to carry the drum and
was later called HMS Persephone, and a Conun was also constructed.
HMS
Persephone
The contract for pipe manufacture was awarded to Stewart & Lloyd, and
this company also undertook to act as agents of the Petroleum Division for the
design and construction of the pipe. Subsequently the company took on the
management of the Tilbury factories. At the same time, the Director of Naval
Construction took responsibility for fitting out HMS Persephone, the design of
the Conun, and the supervision of its construction by Messrs Orthostyle.
A Conun
Loaded with Hamel Pipe
Two adjacent factories were constructed at Tilbury to
weld 40ft (12.2m) lengths of 3” diameter steel pipe into 4,000ft (1,219m)
lengths. While being welded, the pipe was pushed down 4,000ft. conveyor channels
and, on completion, thrown off on to a storage rack. Pending completion of the
Tilbury factories, a few miles of 3” steel pipe were hand-welded in Portsmouth
Dockyard and wound on to Persephone's drum for preliminary trials. These were
entirely successful, and the work was completed by April, so that both the
H.A.I.S. Cable and Hamel Pipe had successfully completed their main trials
programmes by the Spring of 1943.
It was realised very early in the Hamel Pipe
trials that it was not flexible enough be used at the shore ends. It could not
be deployed quickly enough, especially at the French end, where the operation
would be under heavy enemy fire. For the Hamel Pipe to be used, the shore ends
would have to be H.A.I.S. Cable. However, this would reduce the diameter of the
pipe at both ends from 3” to 2”, causing a significant reduction in throughput.
A 3” diameter H.A.I.S. Cable was needed, at least in short lengths, if the Hamel
Pipe was to deliver its maximum potential.
The 3” H.A.I.S. Cable
The success
achieved by the Bristol Channel dress rehearsal had already led to the
consideration of increasing the diameter of the core of the H.A.I.S. Cable to
3”. This dimensional change had been suggested as it would offer a significant
increase in capacity that would reduce the number of cables needed to reach the
required supply target. The requirement for a 3” cable to provide the shore ends
for Hamel Pipe added to reasons for progressing this design modification.
The
design of the new cable was similar in most respects to the 2” cable, with the
exception of the increased tube diameter, and the steel tapes were increased to
22mm in thickness to deal with the greater hoop stress that the cable would have
to withstand. The final overall diameter of this cable, after armouring, was
about 4.5”. Work on the 3” tube design commenced at the Woolwich Works in
September 1943 and in parallel, the coupling design was adapted. New designs
were developed for the 3” cable, with a modified version to fit the ends of the
Hamel Pipe.
A Change of Course
On 23 April 1943, full scale production of both
solutions had been authorised by the Petroleum Division and the Chief of
Combined Operations. They then handed on responsibility of the Operational Stage
to the Petroleum Warfare Department under its Director General, Major-General
Sir Donald Banks (1881-1975), K.C.B., D.S.O., M.C., and Force PLUTO, specially
organised by the Admiralty under the command of Captain John Fenwick Hutchings
(1885-1968), C.B.E., D.S.O., Royal Navy. The Quartermaster General visited the
Watermouth Bay station on 24 April to see the H.A.I.S. Cable system in
operation, and on 29 April he visited the Hamel factories in Tilbury, then
proceeded to Henley’s factory in Gravesend and the Siemens works at Woolwich to
see production of the 2” H.A.I.S. Cable. At Woolwich, he also saw HMS Holdfast
loading a length of 2” H.A.I.S Cable. From his observations he decided that no
further lengths of 2” cable should be made, and that 3” cable, then undergoing
Works tests, should be thoroughly trialled in order to maximise the opportunity
of obtaining the advantage that the 3” cable would provide almost treble the
output of the 2” cable.
During June and July 1943, recommendations were made by
the Quartermaster General's Petroleum Committee, and these were confirmed by the
Chiefs of Staff Committee, that Operation PLUTO should be made a high priority.
Up to this point the plan had only conceived a pipeline from Dungeness to
Boulogne, but for the first time, a second line from the Isle of Wight to
Cherbourg was introduced into the plan. Plans were put in place for pumping
stations of 3,500 and 3,000 tons per day to be built at Dungeness and the Isle
of Wight respectively. Unknown to the members of the Operation PLUTO teams, this
was an indication that the D-Day landings were being planned for Normandy.
Isle
of Wight to Cherbourg Crossing
The decision to lay a pipeline from the Isle of
Wight to Cherbourg would require much larger quantities of cable and pipe, and
so arrangements were made to increase British manufacture as much as possible,
but also to obtain 140nm (260km) of cable from the USA. In addition, it was
planned to duplicate the Tilbury factory for welding, storage and winding Hamel
Pipe in the USA. An American Army proposal had also been developed for laying
cross-Channel lines, but when the progress made in UK with the H.A.I.S. Cable
and the Hamel Pipe was seen by ‘Ike’, General Dwight David Eisenhower
(1890-1969), Supreme Commander of the Allied Expeditionary Force in Europe, he
decided to abandon the American scheme and concentrate on helping the British
programme by supplying cable to the UK design and providing additional pumping
and auxiliary plant from the USA.
The Isle of Wight to Cherbourg route involved
a sea-crossing of about 70nm (130km), instead of the 26nm (48.4km) originally
visualised. This made necessary the provision of larger cableships and the use
of the Conun, which would be loaded till the axles were awash. Following a
successful trial lay of the 3” H.A.I.S. Cable, Operation PLUTO obtained three
more ships to be converted and fitted with cable gear by the Director of Naval
Construction. HMS Algerian was to carry 30nm (56.7km) of 3” cable, and the other
two, HMS Latimer and HMS Sancroft, were to carry 100nm (185km) of 3” cable,
weighing about 6,400 tons. Six Thames barges were also converted and equipped to
handle the shore ends. In addition, a large number of auxiliary vessels were
added to the Operation PLUTO fleet.
Tests using a model Conun at the National
Physical Laboratory showed that it could be handled when loaded with 70nm of
Hamel Pipe, provided that two of the largest class of Ocean Rescue Tugs (the
Bustler) were used ahead, and a smaller tug astern for steering. The production
of five more Conuns was then put in hand. When fully loaded with 70nm of Hamel
Pipe, each Conun weighed 1,600 tons, or the equivalent of a Royal Navy
Destroyer.
Pumping Stations, Storage Tanks & Camouflage
Diesel-driven
reciprocating pumps, each capable of handling about 180 tons per day, had been
ordered in large numbers for the pumping stations. However, with the increase in
capacity required by the longer crossing, it was decided that centrifugal pumps
with a capacity of 1,100 tons per day, powered from the electrical grid, should
also be installed, in order to reduce the number of operating and maintenance
staff required.
Anglo-Iranian undertook the supervision of the construction of
the pumping stations and storage tanks. This involved civilian contractors, the
RE, RASC, and the Pioneers Corp. The RASC were effectively a Bulk Petroleum
Company specially trained for the operation. The Petroleum Board constructed the
land lines and Force PLUTO laid a large number of H.A.I.S Cables and Hamel Pipes
across the Solent to provide redundant lines to the Isle of Wight. These
installations were an ideal opportunity to train the personnel of the large
force that was being assembled and to develop and trial the ships and their
equipment. During these operations, it was established that the cable and pipe
could withstand all reasonable end tensile pulls, but that both would be
severely kinked and damaged if allowed to hang vertically from the laying
vessel, or if they were run back upon.
Unlike many war secrets, Operation PLUTO
could have been given away very easily. If the Germans had got hold of such
information as ‘A petrol pipe like a hollow submarine cable across the Channel’,
the project might well have foundered. Clearly, the pumping stations and storage
tanks might easily be identified by air reconnaissance, so much effort was put
into camouflage techniques to reduce the risk of discovery and attack, and the
pumping station construction was put under the supervision of a Camouflage
Officer. Any plant which might be seen from the air was moved into position
under the cover of darkness, and existing buildings such as bungalows, garages
and ice cream factories were all used as pump houses. Control photographs were
taken at regular intervals by the RAF to reduce the risk of discovery. These
precautions were often expensive and time-consuming but were successful, which
was proven by the absence of any known attempts by the enemy to interfere with
the pumping process during the period that PLUTO was operational.
Enemy Action
The development and manufacture of the H.A.I.S. Cable and the Hamel Pipe,
together with the conversion of vessels and the construction of Conuns, was
completed in just over two years. This would have been an exceptional
achievement in peace time, but it was carried out in what appears to have been
complete secrecy. Given the number of organisations that had to collaborate, it
is impressive that the Germans did not get wind of Operation PLUTO or its
objectives. However, there was a war going on, and throughout the development
programme London was the target of continuous bombing raids. All the major
Operation PLUTO manufacturing sites were on the River Thames at Gravesend,
Tilbury and Woolwich, close to major docks, and thus obvious targets. The
Luftwaffe’s general approach to bombing raids on London was to gather their
planes in the North Sea off the Thames Estuary or in the Channel off Folkestone,
then follow the river or the A20 respectively into London. In both cases the
Siemens Brothers Works at Woolwich was directly in the firing line.
Although
Siemens Brothers was predominantly a British company, at the start of the war
its German counterpart still held a large equity stake, and there were still a
few German-born employees. The two companies had continued to collaborate on
development programmes right up to the outbreak of war, and the Nazis thus knew
all about Siemens Brother and its products, so the Woolwich Works became a
specific target. This can be confirmed because of a unique photograph discovered
by Allied troops when they liberated the Luftwaffe Headquarters in Belgium.
Luftwaffe Aerial Photograph of the Siemens Woolwich Works
The thick black line
in the image above is shown as a thick red line on the original and outlines the
Works at Woolwich with great accuracy. The index at the bottom of the photograph
gives descriptions of the various types of buildings and in some cases
information of what they were used for. None of these footnotes refer to
Operation PLUTO or the H.A.I.S. Cable. There is no doubt that the Nazis
considered the Siemens Brothers Works an important target, and while all three
sites had to deal with German air raids, the Siemens Works probably suffered
more than the other two.
When war was declared on 3 September 1939, the Siemens
Brothers factory site covered some 35 acres (14 Hectares) and employed over
10,000 people. The first air raid on London took place on Saturday 7 September
1940 and commenced at 17:00 that evening. The following account is taken from
Siemens Brothers official reports:
Around 5,000 employees were working that
Saturday afternoon. There was no indication of anything abnormal, and when the
sirens sounded, an established routine was quietly followed. Air Raid
Precautions (ARP) personnel reported to their stations, and all other employees
evacuated to the shelters, as they had done on many previous occasions without
any incidents. However, on this occasion the sirens were followed quickly by the
roar of enemy bombers, and out of the blue evening sky flecked with fleecy white
clouds, hundreds of enemy bombers supported by hundreds of fighters weaving
around them came in a steady stream from the south-east, and almost immediately
a rain of bombs commenced to fall on the Surrey Docks and Woolwich Arsenal. The
crash of falling bombs was continuous, and within five minutes high columns of
black smoke began to rise from the district, which appeared to be blazing over
its whole area. No fewer than sixteen high-explosive bombs fell inside the
boundaries of the Siemens Works and caused very great damage.
High Explosive
Bomb Damage
This was the start of what was known as the ‘Blitz’, and this
bombing campaign continued with decreasing intensity until the end of the war.
In October 1945, a plan of the Works was marked up with the number of High
Explosive (HE) missiles of various types that landed on the site, and their
locations. In addition, the incendiary bombs that were dropped on the premises
were scattered in such large numbers that it was impossible, after the first
thousand, to keep accurate records of their location, but their general
distribution was indicated on the plan. Although a great number of land mines
were dropped in the Woolwich area, only one landed on houses, in Hardens
Manorway, 50 yds (45m) to the west of the Works, shown in the plan with a
parachute attached.
1945 Site Plan showing the Location of Dropped Bombs
In
addition to the bombs recorded within the Works, in the later stages of the war
three V1 rockets, known as ‘Doodlebugs’, exploded in the River Thames north of
the Works, and two V2 rockets later exploded in mid-air above the Works.
During
the war, the Woolwich site was hit on no less than twenty-two occasions, and the
research department in Blackheath was also damaged by HE and incendiary bombs.
After 7 September 1940, the bombing of London continued with great intensity for
a continuous period of 90 nights. Records show that the intense air raids by
bombers only lasted for a period of six months, but occasional heavy raids
persisted throughout 1941. Once the Battle of Britain was won, the daylight
raids ended, and although night raids followed into 1942, they grew gradually
weaker and proved far less accurate, so very few HE bombs were dropped within
the Works. These night raids did continue spasmodically until the start of the
V1 flying bomb attacks, which commenced on 13 June 1944. These continued day and
night until they were replaced by V2 rockets, the first of which hit London on
Friday 8 September 1944, and the V2 attacks continued until the launch sites in
mainland Europe were final overrun by Allied troops at the end of March 1945.
There were, of course, many bombs, flying bombs and rockets that landed in close
proximity to the boundaries of the Siemens Works, and although these caused only
limited blast damage to the Works, they did cause serious stoppages in
production by interfering with utility services such as gas, water, electricity
and telephone. Apart from the incidents that occurred in and around the factory,
production was also adversely affected when there were attacks on the district
as a whole, or when enemy planes were over the Works, as many thousands of
man-hours were lost through the employees having to take cover in the Works air
raid shelters. A further disruptor was injuries to employees and damage to their
houses in the local area. Remarkably, the Siemens Works got though the war with
only three fatalities and one serious injury, which required the amputation of a
leg.
Despite all this enemy action, the H.A.I.S Cable development and
manufacture was successfully completed in time to meet the finally required
milestone of Operation PLUTO.
The Installation of the PLUTO system
Full-scale
trials were made with the Conun in the River Thames in February 1944, and in
Bournemouth Bay in April 1944, during which the technique for towing the Conun
at up to 7 knots was perfected, and the decision was taken to moor the drum at
the beginning of her run and haul in the H.A.I.S. Cable shore length by means of
a warp pulled in by a plough traction engine. The far-end H.A.I.S. Cable would
then be laid out parallel to the shoreline and subsequently pulled in from the
beach. However, both these methods proved difficult to accomplish and an
alternative approach would later be adopted.
As is well known, the D-Day
landings, codenamed ‘Operation Neptune’, took place on three beaches (Gold, Juno
& Sword) in Normandy on 6 June 1944. However, Operation PLUTO did not commence
until 12 August, due to the delay in capturing Cherbourg and clearing the
harbour of mines. The first line was laid across the English Channel from the
Isle of Wight to the tip of the Cherbourg Peninsula. Two 3” H.A.I.S. Cables and
two Hamel Pipelines with H.A.I.S Cable shore ends were laid on this route. Each
of them was 70nm in length and the average time taken to lay the H.A.I.S Cables
was about 10 hours. These were followed in the next few weeks by two Hamel
Pipes. Petrol was pumped through these pipelines to support the Allied advance
along the Channel Coast to Boulogne and Calais
The advance of the Allied Armies
into Belgium and Holland was so fast that it became essential to shorten the
lines of supply, and so further pipelines were run across the Channel on the
original planned route from Dungeness to Boulogne. The lines from Dungeness were
run to a beach inside the outer harbour at Boulogne. This saved vital time by
obviating the need to clear the heavily mined beach at Ambleteuse that had
previously been chosen as the landing point. This change to the route involved a
longer run and a more difficult approach, but a technique of laying the main
lengths of H.A.I.S. Cable over the stern and dropping the ends onto the seabed
was devised. These ends were to be picked up later by the shore-end barges and
coupled to the shore end cables at a suitable state of a later tide, and then
the shore ends were landed. Once this had been perfected, lines were laid and
commissioned without incident. The average time of laying the H.A.I.S Cables on
this route was only five hours and eleven H.A.I.S. Cables were finally
installed.
Six Hamel Pipes were also laid on this route. As described earlier,
the method of pulling in the Hamel Pipe shore ends from the Conun had proved
difficult, if not impossible, both in trials and on the Isle of Wight to
Cherbourg lines. This issue was resolved by winding onto the Conun short lengths
of H.A.I.S. Cable coupled to the beginning and end of each length of Hamel Pipe.
These tails were led and followed respectively by a special floating wire. The
Conun could then be handled like the cableship laying each tail on the seabed
for the barges to recover the floating wires. They could then couple the pipes’
cable tails to the shore-end cables and deploy them with the same method that
was used to complete the H.A.I.S. Cable lines.
Force PLUTO was responsible for
the installation of the line to above the low-water mark on each shore, and the
RE and RASC then connected the ends with steel pipe to the valves and filters
provided on the pump delivery lines in the UK and, at the far end, to valve
manifolds. Main and group control rooms were set up, with telephone
communication between themselves and the pump houses, and to the opposite
receiving terminals. These locations were provided with diagrams on their walls
on which the control officers could use coloured discs on hooks to indicate the
direction of flow of oil, the pumps and lines in use, etc., at any time.
As
described earlier, the couplers contained bursting discs to contain water under
pressure in the H.A.I.S. Cables during the laying operation and until the
sections were connected together. When a H.A.I.S. Cable line was ready for
commissioning, a pump was started at the UK end and the rate of rise of pressure
was monitored and recorded. The rate of rise was slow at first, but when it
reached 400psi (27.6 bar) the first disc was broken, and the pressure was seen
to fall. It then began to slowly rise again until the next disc burst. This
process was repeated at each disc until the liquid began to flow at the far end
and this was then confirmed to the pump house, via a direct telephone line from
the receiving terminal.
Each of the 3” lines run from Dungeness were capable of
delivering about 400 tons a day, or 120,000 gallons. These lines were supplied
and installed sufficiently quickly to keep ahead of the capacity required to be
pumped from Boulogne into the French interior. The total length of the pipelines
laid on the Boulogne route was 500nm (928km), which provided a total capacity of
more than 4,500 tons, or 1,350,000 gallons, per day, and 1,000,000 gallons a day
were pumped across the Channel for some weeks.
There was a valve manifold system
on the beach at Boulogne, with a tank at beach level, that provided facilities
for test purposes, but the flow was usually taken direct through three lines of
6” Victaulic jointed pipe up to tanks of 1,200 tons capacity on the cliffs north
of Boulogne.
As the Allied Armies advanced, the lines were extended inland
through 6” Victaulic pipelines. Eventually, petrol could be pumped from Boulogne
to Calais, Ghent, Antwerp, and Eindhoven, then across the Rhine at Emmerich.
From Cherbourg the route was extended to Alençon and Chartres, then south of
Paris to Chalons-Sur-Marne, into Luxembourg, crossing the Rhine at Mainz, and
part way to Frankfurt. The pipeline’s terrestrial extensions were constructed
under the control of the Quartermaster General to the Allied Forces, General Sir
Thomas Sheridan Riddle-Webster (1886-1974). The final joint was completed on 10
April 1945.
The Complete PLUTO Pipeline
In total, over 172 million gallons were
delivered over PLUTO and its extensions by the end of the Second World War!
Siemens’ Final Contribution
Production of the 3” H.A.I.S. Cable continued at the
Woolwich Works until September 1944. By then, Siemens had completed the
manufacture of a number of operational lengths of the 3” H.A.I.S Cable. One of
the longest sections was 35nm (85km) and weighed over 2.200 tons when the core
was filled with water. The factory coil for this was 10ft (3m) high and 65ft
(19.8m) in diameter. The space required for coiling such long lengths
necessitated the erection of a special building, with extra-strong cable sheaves
and hauling equipment located in the roof. A long, counterpoised steel arm was
designed and fitted to facilitate the handling of this extremely heavy cable.
35nm Section of 3” H.A.I.S. Cable Being Coiled in the Tank House
Altogether,
Siemens manufactured and delivered over 200nm of 3” H A I S. Cable to the
Petroleum Warfare Department. Some 280 couplings were supplied, and with each
set of two couplings a complete equipment set of special tools was provided,
together with numbered spare parts, to facilitate the rapid trimming of the
cable ends and fitting of the couplings.
Conclusion
There is no doubt that
Operation PLUTO was pivotal to the liberation of Northern Europe by the Allied
Armies in 1944-45. Together with superior manpower and the hard-won control of
the skies, PLUTO was the third key pillar in the Allied victory. Without
adequate fuel supplies, no matter how successful the military campaign, the
Allied forces would have quickly reached the limits of their logistical supply
chain, and would have been forced to dig in. Had Operation PLUTO not happened,
the advances inland after D-Day would have bogged down in a new ‘Western Front’
much closer to the beachheads, and this would have bought the Germans vital time
to prolong the war.
German military strategists understood that the enormous,
highly mechanised Allied armies would have a voracious appetite for fuel. They
assumed that this demand could not be met, unless major Channel ports were
captured in which bulk tankers could be docked to supply the forces. This is why
the German garrisons at Channel ports such as Cherbourg were instructed to hold
out until the bitter end, and why, towards the end of the war, Antwerp became
the focus of V1 and V2 rocket attacks. Without timely intelligence of the
project, which was never forthcoming, the German High Command could not have
anticipated the massive quantities of piped fuel that PLUTO delivered.
Therefore, alongside its incredible engineering achievements, the measures taken
to keep Operation PLUTO secret were vital to its success.
The contribution made
by the employees of Siemens Brothers to Operation PLUTO, in such difficult
circumstances, was a major contributory factor to its success, and should not be
forgotten.
The authors have established that Royal London, the current owners of
the Faraday Works, are working with developers U+I on revised proposals for the
site, which will shortly be the subject of public consultation. The new
heritage-led scheme will retain and restore four of the remaining buildings on
site which formed part of the Siemens Brothers Works, including 37 Bowater Road,
which has recently been designated as a Grade II listed building by Historic
England, in part because of its contribution to industrial history and
innovation. The developers have committed to telling the rich history of the
site and recognising the vital role the site played in both World Wars,
including its contribution to Operation PLUTO and the HAIS Cable. They are
currently exploring initiatives such as the Red Wheel Scheme run by the National
Transport Trust, as well as the use of QR tags that are being promoted for use
at key historically significant stop points along the Thames River path between
the Old Royal Naval College and the O2 Arena. The QR tags are intended to link
to contextual history resources online, and a number could be deployed on the
path through the Faraday Works. In addition, public art installations are being
considered to commemorate key innovations by Siemens Brothers such as the iconic
Neophone. Finally, we are pleased to report that Local historians are in close
contact with the developers, U + I, to ensure that these important contributions
by Siemens to the war effort, and to the development of telecommunications in
general, will be commemorated in an accurate and appropriate manner.
References
Siemens’ Part in the Design of the HAIS Cable and Coupling, Siemens Brothers, 26
June 1945 Official Record of Damage By Enemy Action to Woolwich Works, Siemens
Brothers, October 1945 Operation Pluto: A paper read to the Royal Society of
Arts, A C Harley, 14 November 1945 Development of the HAIS Cable, Siemens
Brothers Engineering Bulletin No.224, January 1946 Siemens Brother 1858 – 1958,
J. D, Scott, published by Weidenfeld and Nicolson, 7 Cork St. London W1, 1958
Acknowledgments
The authors would like to thank Anthony Chapman and Linda
Richardson for giving them access to the documents listed in ‘References’, and
for permission to reproduce the images used in this article. We would also like
to thank Clive Jefferys for his advice on the strategic benefits of Operation
PLUTO and the German bombing campaigns during the Second World War.
