is hard to picture the former iron industry in today's
countryside of small fields, woodlands and steep,
narrow, gill valleys. But in this landscape exist all
the necessary raw materials that allowed iron to be
smelted for over 2,000 years. There were no
planning laws in those days and no planning officers to
put a spanner in the works.
Wealden geology of sands and clays yielded the iron ore,
as well as the stone and brick to build the furnaces;
the woodland provided the charcoal fuel; and the
numerous small streams and valleys ensured water power
for the bellows and hammers of the forges and furnaces.
two periods - in the first two centuries of the Roman
occupation, and during Tudor and early-Stuart times -
the Weald was the main iron-producing region in Britain.
Julius Caesar first drew attention to iron being
produced in the coastal parts of Britain. Archaeologists
have found evidence of iron working from the late Iron
Age at sites near Crowhurst and Sedlescombe in the
south-eastern High Weald.
the Romans invaded in AD 43, they found a
well-established local tradition of iron making, using
small, clay bloomery furnaces. With growing markets
generated by the building of towns, villas and farms,
the Romans encouraged this native industry. Sites from
the period have been found all over the eastern part of
the High Weald.
'Classis Britannica', or British Fleet, an imperial
supply organization as well as a navy, took a strategic
role in iron production. It managed several large
smelting sites in the area around Hastings, such as one
at Beauport Park, near Battle. This may have produced as
much as 30,000 tonnes of iron over 130 years, and a
substantial bathhouse was built there for some of the
know little about iron making in the Weald in Saxon
times, and the industry receives only one mention in the
Domesday Book for Sussex, at a location near East
Iron making furnace in blast
during the Middle Ages iron production grew steadily,
concentrated more in
the northern part of the Weald.
Accounts have survived from 14th-century works at
Tudeley in Kent, and excavations have confirmed medieval
references to iron makers in Crawley and near Horsham.
Towards the end of the period, water-power began to be
used for forging iron, heralding the introduction, in
1496, of the blast furnace.
from northern France, and operated by skilled, immigrant
workers, the blast furnace was a much larger, and more
permanent structure than the bloomery; and instead of a
few kilos of iron being made, daily output was nearer a
ore and charcoal were required, and the need to operate
the bellows by waterpower, instead of by hand, meant
that ponds had to be created to store the water. In
addition, the higher temperatures in the furnace meant
that a different type of iron was being produced. A
second process ˜ the forge, with its own pond and
supply of charcoal - was needed to refine the iron.
the mid-16th century there were 50 furnaces and forges,
and that number had doubled 25 years later. All over the
Weald, the iron industry was having an effect, with
large numbers of people employed in digging ore, cutting
wood and transporting both raw materials and products.
furnaces made "sows", or lengths, of iron for
refining, but from the 1540s a small number began to
make cast-iron cannon, a product that grew to be a
profitable, and sometimes illegal, export. Improvements
in house design led to the building of chimneys, and the
need for iron fire-backs to protect the brickwork. Many
Wealden farmhouses contain examples of these decorative
and functional plates. In several Wealden churches there
are examples of iron memorials. The oldest is in Burwash,
dating from the 1530s, while Wadhurst church has over
30, dating from the early-17th to the late-18th
competition from imported iron increased, the Wealden
ironmasters began to concentrate increasingly on gun
founding, and examples can be found all over the world,
wherever Britain fought or traded. Eventually, the onset
of the Industrial Revolution took heavy industry north
to the coalfields, and the last furnace in the Weald, at
Ashburnham, closed in 1813.
where are the remains of iron production? Building stone
was too valuable in the Weald to be left unused, so the
works were dismantled, and the woods grew back over the
former sites. Only the tell-tale waste, called slag,
from the smelting process, and some of the hammer and
furnace ponds are left to remind us of a once-great
WEALDEN IRON RESEARCH GROUP - WIRG
Wealden Iron Research Group was founded in 1968, by
Henry Cleere and David Crossley, to update the
pioneering work of Ernest Straker whose monograph,
Wealden Iron, had been published in 1931. Starting off
as a federation of local groups, it coalesced in the
early 1970s under the leadership of the late Fred
Tebbutt, a distinguished amateur archæologist, who
became its first Chairman. Much of the early work of the
group centred around the update of Straker's work, but
it was soon realised that much lay undiscovered.
survey of an area of the central Weald revealed a dense
concentration of early iron smelting sites, or
bloomeries, and this has acted as an incentive for
future work. Experiments in making iron were started,
and the group won the BBC's 'Chronicle' Award for Archæology
in 1981. The publication, in 1985, of The
Iron Industry of the Weald, by Cleere and
Crossley, was the fulfilment of the group's initial aim,
but many questions remained unanswered, and the group
continues an active programme of research.
by Jeremy Hodgkinson of the Wealden Iron Research Group.
Illustrations by Mike Codd, West Sussex County Council
Wealden Iron Research Group (WIRG) website provides information on a wide
range of the groups activities together with a general introduction to
iron production in the Weald. The Weald has been identified as a key
iron-producing region for the British Isles and it contains nearly 800
identified iron-making sites dating from the pre-Roman period up to the
19th century. The WIRG, established in 1968, has carried out a wide range
of activities on the Weald. The website contains information on the
group's research aims, meetings, excavations and other fieldwork together
with details on how to become a member.
of the key group activities is conducting a programme of experiments
intended to replicate the bloomery smelting process used in the Weald
during the Roman occupation. The website contains a highly detailed and
well-illustrated section on these experiments together with details of the
groups publications and annual bulletin of research. Aside from providing
details on the WIRG itself, the website also contains a brief history of
the iron industry in the weald from prehistory to nineteenth
WIRG website is simply and consistently set out using frames and is via
navigation a standardised side menu. The illustrations are clear, are
captioned and linked to larger versions. The site also contains a number
of links to related websites.
steam hammer of 1840 at work in 1871
to join WIRG
of WIRG is open to individuals, families and institutions, students and
those of pensionable age, and includes a bi-annual Newsletter and the Wealden
Iron Bulletin. Activities
include a Field Group, which organises a programme of fieldwork in the
autumn and winter, bi-annual meetings with visiting speakers, small-scale
excavations, and a variety of other projects undertaken by its members.
WIRG administers the Tebbutt Research Fund which awards small grants
towards research into the Wealden iron industry.
current subscription rates in Sterling are:
may find out more by emailing David
an application form in PDF format by clicking HERE.
Complete and post it to The Hon. Secretary WIRG, 2 West Street Farm
Cottages, Maynards Green, HEATHFIELD, Sussex, TN21 0DG, with your cheque
made payable (in sterling) to Wealden Iron Research Group. If you
pay tax, you may wish to complete a Gift
Aid form to help the Group reclaim your tax.
progress in the Melting of Iron
According to history, cast iron was first produced succesfully by the
Chinese 800-700 B.C.(1) Even though iron was produced many centuries
before, it apparently could not be cast because the furnaces were
incapable of producing the required temperatures. However, the Chinese, as
pointed out by Simpson(1), "had developed melting equipment capable
of producing greater draft than hitherto had been possible".
Another reason for the succes of the Chinese in being able to produce cast
iron, as mentioned by Simpson 1), was that they reduced iron oxide by
heating in the presence of an exess amount of carbon, apparently in the
form of charcoal. This procedure resulted in a soft, pure iron with a
melting point of 15300C (27860F). The iron was then
carburized, reducing its melting point to about 11700C (21380F)
thereby making it easier to melt in their high draft furnaces.
Additional references indicate that the Chinese used some high phosphorus
coal along with high phosphorus iron ore as charge materials (1,2). These
materials, by lowering melting temperatures, reduced the amount of blast
needed to melt the iron.
From these early beginnings, the interest in cast iron continued to grow.
Many applications for this "new cast metal" were made possible
by improvements in melting equipment and techniques as well as great
progress in the art of molding. Several engineering applications employed
cast iron from time to time, including iron chain suspension bridges, the
first of which were constructed by the Chines in 56 A.D. (2) However, iron
was not generally cast in what might be called "substantial
quantities" in Europe untill the fourteenth century A.D. (1).
The Development of the Blast Furnace
Although the early furnaces for melting iron were probably a very crude
form of blast furnace, the development of the Catalan forge in Spain in
the eight century A.D. was most likely the forerunner of the blast furnace
(1). In the Catalan forge, iron ore and charcoal were charged vertically
in the top, resulting in a "loupe" or ball of iron which was
"hooked out and hammered into a bloom".(1) By modifying this
simple furnace, the Swiss made an improved melting unit which was
vertical, above the ground, and charged with alternate layers of ore and
charcoal. The next improvements leading to the development of the true
blast furnace were made by German and Swedish craftsmen in about 1000
During the next 300 years these early blast furnaces were improved and
made larger. In 1325 A.D., water driven bellows, which delivered
sufficient draft to make hot molten metal directly from the blast furnace,
were introduced. Development of these bellows led to the production of
substantial amounts of pig iron in Europe by 1400 A.D.(1) and marked the
beginning of modern iron foundry practice.
Early Improvements in the Quality of Cast Iron through the Use of
When the famous Spanish Armada attempted to invade England in the
sixteenth century, an important step in improving the quality of cast iron
was discovered(3). In his historical book "Full Fathom Five"
about an expedition organized to recover the buried wrecks of the
"invincible" Armada off the coast of England, Colin Martin (3)
indicates that the cast iron cannons, shot and anchors of the Spanish
fleet were inferior to those used by the British. Martin cites this as an
important reason why the British were able to defeat the Spanish and thus
prevent the conquest of England.
Even though the Spaniards possessed a good quality hematite ore, they
produced poor quality iron guns, anchors and shot due to their lack of
knowledge of the behavior of cast iron.
The historical evidence indicates that in the smelting and fluxing of the
ore, the refining after smelting, and in the molding and casting
techniques, the Spanish were years behind the English. Practically all of
their iron castings contained slag. The inferior quality and brittle
nature of the shot, coupled with the explosive force of the potent
"black powder" caused the shot to crack and partially
disintegrate prior to hitting its target. Similarly, many of the cast iron
guns exploded during the firing, indicating poor strength and poor ability
to absorb shock and vibration. For the same reasons Spanish anchors broke
under the stresses of heavy seas and were the cause of many shipwrecks.
What were the reasons for the superiority of the English cast iron, which
was the envy of their continental competitors? Martin points out that
there was no magic formula. All of the practices of the 16th century
founders of the Weald of Sussex, the seat of the English iron industry at
that time, are known to us. The practice of weathering the ore for several
months washed out many impurities. The ore was then crushed and washed
again. Fossilized gray shells inherent in the ore resulted in a high
degree of fluxing during smelting, allowing the removal of surface dross
and other impurities.
The advanced knowledge of the British founders during this period is
demonstrated by the fact that the gun and shot molds were dried and warmed
prior to the casting of the iron. The metal, in turn, was poured each time
at as even a temperature as possible. This practice minimized what we
refer to today as "undercooling" and established close to
equilibrium conditions of solidification.
After pouring, the castings were allowed to cool gradually in the molds to
room temperature. This procedure minimized the stresses in the finished
castings. The Spanish, on the other hand, as pointed out by Martin, cooled
the castings as quick as possible in order to expedite production. Their
practice often involved water quenching the castings, which contributed to
stresses and cracking.
For several years after the defeat of the Spanish Armada, iron founders on
the continent attempted to determine the reasons for the better quality of
the British castings. In 1619, a Dutchman, Jan Andries Moerbeck, proved
that he was on to something new and revolutionary in the art of iron
founding, by applying for and obtaining a twelve year patent involving the
use of iron ore from the Weald of Sussex. By comparing the English ore
having build-in flux, with their flux free, but otherwise good quality
hematite ore, the Dutch developed the use of limestone for fluxing. This
new technique spread rapidly across the continent to Germany, France and,
eventually, Spain, and should be credited as a major contribution in the
development of engineering cast irons.
of modern iron making blast furnace
Refinements in the Process of Making cast Iron
The next significant development, credited to an English iron-founder named
Darby in 1730, was the discovery and production of coke which lowered the
cost of producing cast iron. This development encouraged experiment for
better quality cast iron with improved mechanical properties. As a result,
the French founders tried remelting pig iron in separate, smaller furnaces.
This type of refining resulted in more uniform iron with respect to
chemistry and was another big step toward the development of engineering
grade cast iron. Untill this time, apparently most iron castings were poured
from iron directly from the blast furnace.
The improved quality iron produced by remelting pig iron in separate
furnaces made it possible for James Watt to build the first steam engine in
1765. Watt's steam engine, in turn, was used to provide the air blast for
operating the first cupola build in 1794 by John Wilkinson (1). The
controlled air blast plus the higher melting temperatures in the cupola
further improved the quality of the cast iron. As a result, designers,
engineers, builders and others became more interested in cast iron as an
Applications for the steam engine in such fields as land and sea
transportation, agricultural equipment and, later, electrical poweer
generation, created a demand for large quantities of high quality gray cast
iron. As this demand grew, so did the need for higher strength and better
quality iron requiring more efficient melting equipment, improved charge
materials, and closer control of the melting operations.
The Early Use of Ferrosilicon in Cast iron
About 1810, Bergelius, a Swedish chemist, and, Stromeyer, a German
physicist, operating independently, produced ferrosilicon (1). A mixture of
silica, carbon and iron fillings was melted in a sealed crucible. Stromeyer
produced several grades of ferrosilicon by this method.
Although there appears to be no record as to how the ferrosilicon was used, it
was probably added to the melting furnace. Most likely the iron founders became
interested in a source of silicon because of the differences in silicon content
in the various pig irons produced by the different furnaces due to varying
silica content in the iron ores used. The advantages of higher silicon in making
softer and less brittle irons were obvious. By adding silicon to the furnaces
along with charge materials consisting of scrap and pig iron, the foundrymen
were able to make consistently good quality cast iron. They soon learned that it
was advantageous to have the silicon low in thick section castings and high in
thin section. It is not known that ferrosilicon was added to the ladles in the
early to middle 19th century.
In 1885, Turner (4) ran a number of experiments in which ferrosilicon was added
to white iron to produce high quality gray iron castings. It is reasonable to
assume that the ferrosilicon was added to the iron in the ladle. If so, this
would be an indication that some of the early investigators recognized the chill
reducing potential of adding ferrosilicon to the ladle.
In 1920, G.Schury (5) discussed the use of ferrosilicon briquettes in the
cupola. A discusser of the paper indicated that he had added ferrosilicon to
molten iron as early as 1890 for improving cast iron properties.
The knowledge of silicon control would trigger another series of improvements on
cast iron structures and mechanical properties, a process that in fact is
continuing up till the present day.
Young (Exp Bloomery at St Fagans, Cardiff)
reconstructed medieval bloomery
Evelyne Godfrey, Gerry McDonnell et al Bradford University
Video of operation of a bloomery in Mali in the 1990s by the Dogon tribe
Sweden - experimental bloomery operation (in Swedish)
iron & Steel Industry in the Black Mountains (South of France)
Pierre-Michel Decombeix et al - UTAU, Toulouse (Translation from French)
Smelters Art' - Rockbridge Bloomery, Lee Sauders & Skip Williams
Making of the High Weald
Archaeological Society The
in Sussex Classis
Iron Smelting at Scatness Experimental
Bloomery Site in Wales
Farm Roman Villa smelting experiments
Iron Smelting at Rievaulx Historical
of Materials Science, Oxford University
Ironbridge Gorge Museums - Shropshire UK
Ironworks, Hampshire Duddon
Real Wrought Iron Company The
Wilkinson Family, Ironmasters
du Saint Maurice, in Canada Saugus
Furnace, Massachusetts, USA Hopewell
Furnace, Pennsylvania, USA
de la Métallurgie et de l'Industrie de Liège (in
Ironworks - Sweden
INDEX A - Z
CASTLE - WETLANDS
HEAD - BELL
TOOT (BELLE TOUT) LIGHTHOUSE
SHOW and GYMKHANA
VALLEY - EXCEAT
AND BOROUGH COUNCILS
SHOPS - PIER
SCHOOL - LINKS
THINGS TO DO GUIDE
BATTLE OF HASTINGS
MILL, OLD HEATHFIELD
Electricity Generating Works Circa. 1900 -
Room | Floor
Plan | Ron
Park | Machinery
House | Argus
Construction | Rural
Supply | Sussex
Express 1913 |
Sussex CC | English
Heritage | SIAS
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