TPi October 2010

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56 Tube Products International October 2010
pipesPVC, PE & XLPE
“Large alder trunks, with bark remaining,
had been bored through with an auger
to create a 5cm pipe for the water. The
individual lengths were connected by
rectangular slabs of oak, without any use
of iron or lead fittings”.
This account, given in 2005 by an
archaeologist working at the Vindolanda
Roman fort, inNorthumberland, England,
describes a timber water main installed
approximately two millennia before it
was unearthed. Water is thought to have
been supplied from a nearby spring and
distributed around the fort through the
main and a network of similar wooden
pipes, fastened together by oak pegs.
It is perhaps curious that the Romans
were using timber pipes at a period
when they were already masters of
pipe production in lead and terracotta,
and had built brilliantly engineered
aqueducts serving urban populations.
Yet the fact that water was still ‘on
tap’ (or at least, flooding daily into the
archaeologists’ trenches at Vindolanda
just five years ago) is testament to this
ancient pipe making technique.
More importantly it illustrates that pipes
were, even then, becoming diverse
in their design and construction.
Rather than adhering to the most
technologically advanced solution of the
age, pipe makers used locally abundant
materials to minimise cost, time and
effort. The exploration of new materials
for pipes and pipe fittings has since
produced a wealth of options, leading
to the widespread use of polyethylene
pressure pipe systems.
Incidentally, the ability to contain water
under pressure was not as relevant
to Roman potable water pipes as it is
today. Flow was achieved by gravity
and siphoning, and common practice
was to allow water to flow continually
at the point of use. In the case of lead
pipes this counteracted the damage to
public health, as it reduced contact time
between the potable supply and the
poisonous metal.
Centuries after Roman occupation,
during the Industrial Revolution, trees
were once again playing a part in the
history of the British pipe industry, this
time in the form of charcoal. Iron was
traditionally smelted using charcoal and
pipes made from cast iron produced in
this way were certainly in use here in
the late 17th century. (Cast iron pipes are
actually recorded as early as 1455, in the
German town of Dillenburg. However,
the economics of manufacturing water
pipes in this material were apparently
not widely favourable until much later.)
As a forerunner of modern pipe systems,
cast iron pipes received a boost in
1709, with the appearance of Europe’s
first successful coke-fired blast furnace.
Abraham Darby rebuilt the existing
furnace at Coalbrookdale and fuelled
it using coke, which was far better than
coal for iron smelting, and at this time
was more readily available than locally
made charcoal. This was a significant
technological breakthrough and laid
the foundations for British cast iron
production on a large scale.
In London, cast iron was used for public
water supply from the mid-18 th century,
although this was restricted to trunk
mains. Examples are documented:
approximately 1,500 yards of 12" pipe
were laid at Chelsea in 1746 and in
Scotland, Edinburgh subsequently
installed six miles of 9" cast iron mains.
At this time flange ends provided
the common method of jointing cast
iron pipes. It appears this was not
particularly reliable, as contemporary
engineers recorded numerous failures
caused by expansion and contraction,
due to seasonal temperature changes.
However, in the late 18 th century Thomas
Simpson introduced a repair method for
flanged pipelines, which used molten
lead to join broken pipes. He was
credited with developing the run-lead
spigot and socket joint in 1785, which
accommodated thermal movement
more successfully than flanges.
The nascent metal pipes industry, with
the industrial Midlands at its centre,
created companies that were to develop,
amalgamate and go on to produce
polyethylene pressure pipe for water. It
also ultimately led to the formation of
the UK’s largest ever single organisation
in this field, Glynwed Pipe Systems Ltd.
A noteworthy step came in 1862,
when A&J Stewart and Menzies Ltd of
Glasgow produced the first gas pipes
in the UK. In 1895 this company was
merged with Lloyd and Lloyd Ltd of
Birmingham, thus forming Stewarts and
Lloyds. At this point both companies
had existed for more than 40 years and
had risen to become the largest iron and
steel pipe manufacturers in Britain.
Around the same period the first UK
factories for lead pipe and copper
pipe production were established at
Ironbridge (Glynn Brothers) and Bilston
(Wednesbury Tubes), respectively.
The two were later to become united
under the name Glynwed. The growth
of Glynwed, in parallel with that of
Stewarts and Lloyds, culminated in the
creation of Glynwed Pipe Systems Ltd
in 2000.
Along the way, Stewarts and Lloyds
acquired the Victaulic Company, which
Innovation in the PE pipeline
By Richard Graty, marketing manager, GPS PE Pipe Systems
Richard Graty
Remains of the Vindolanda Roman fort
Lead pipe at the Roman
baths in Bath, England