Reasons for Designation
Iron has been produced in England from at least 500 BC. The iron industry,
spurred on by a succession of technological developments, has played a major
part in the history of the country, its production and overall importance
peaking with the Industrial Revolution. Iron ores occur in a variety of forms
across England, giving rise to several different extraction techniques,
including open casting, seam-based mining (similar to coal mining) and
underground quarrying, and resulting in a range of different structures and
features at extraction sites. Ore was originally smelted into iron in small
relatively low-temperature furnaces known as bloomeries. These were replaced
from the 16th century by blast furnaces which were larger and operated at a
higher temperature to produce molten metal for cast iron. Cast iron is
brittle, and to convert it into malleable wrought iron or steel it needs to be
remelted. This was originally conducted in an open hearth in a finery forge,
but technological developments, especially with steel production, gave rise to
more sophisticated types of furnaces. A comprehensive survey of the iron and
steel industry has been conducted to identify those sites of national
importance that represent the industry's chronological range, technological
breadth and regional diversity.
The scale of production using the water powered blast furnace was far greater
than that of the bloomery, and blast furnaces and forges became widely
distributed across the Weald in the post-medieval period. About 110 furnace
sites have been identified so far, although none of these retain standing
structures.
The charcoal fired furnace functioned most efficiently if run continuously for
as long as possible, and predictable supplies of ore, fuel and water were
essential. Furnaces were therefore sited near to a water supply to power the
bellows and in wooded areas to secure a ready supply of charcoal, but not
necessarily close to ore deposits - ore being a less fragile material to
transport than charcoal. In areas of relatively low rainfall, cross-valley
dams were built to impound the free-flow of a stream, and this is demonstrated
at Bedgebury.
Essentially, a blast furnace consisted of a vertical stack, about 6m-8m high,
with a hearth at its base. Air was forced into the furnace through nozzles, or
tuyeres, to ensure a high temperature was maintained. The ore and charcoal
were fed in at the top of the stack which was reached by means of a charging
bridge or ramp. The molten iron which collects at the base of the structure
was run out through a tap hole into casting pits. Impurities in the ore, or
slag, floated to the top of the molten metal and were removed through another
tap hole.
The remains of Bedgebury Furnace survive comparatively well, and the lack of
significant reuse of the site, since its abandonment in the late 17th century,
will have helped to preserve the remains of components associated with its
use. The charging bank and dam survive as prominent earthwork features, and
the foundations of the furnace, its casting pit and components of the water
supply, including the wheel pit and tailrace are expected to survive in buried
form. Waterlogged remains of bellows and fragments of the water wheel may also
survive, together with deposits of slag and hearth lining, enhancing our
understanding of the operation of the furnace. The importance of the site is
amplified further by the preservation of its landscape setting within which
the relationship between the furnace and its local supply of fuel and water
power can be clearly appreciated.
Details
The monument includes the furnace of an early post-medieval ironworks,
situated within a stream valley of the High Weald, 2km west of Hartley
village.
The water powered furnace, known in documentary sources as Bedgebury (or
Badbridge) Furnace, survives in the form of a substantial earthen dam (or pond
bay), with associated spurs and the buried remains of the working area on its
north western side. The furnace was established by 1574 when the site was
owned by Sir Alexander Culpeper. The site subsequently changed hands on
several occasions and is particularly noted for the innovative gun founding
activities of John Browne, who was casting ordnance here in 1637 and
attracting complaints from the residents of Cranbrook about his consumption of
wood. The furnace was discontinued before 1664, although it was temporarily
re-stocked during the second Dutch War of 1664-67.
The north east-south west aligned dam occupies the width of the valley and is
breached by the stream at its south western end. The earthwork, which stands
to a height of up to 4m, measures about 125m in length and is 17m wide. An
earth bank, or spur, projects behind the dam at its south western end and was
built to protect the working area from the former spillway. A second spur,
midway along its length, is thought to have been a charging bank to serve the
furnace. Deposits of furnace slag, as well as brick and tile from former
buildings, have been identified within the working area. Cartographic evidence
indicates that two buildings stood within the working area in 1908, although
these may have been of a later date than the furnace. Traces of these
buildings and other features associated with the operation of the furnace are
expected to survive in buried form, including the foundations of the furnace
stack, hearth and casting pit, as well as the wheel pit and channel, or
tailrace, which carried the water away from the wheel. To the south east of
the dam, beyond the area of the monument, field boundaries reflect the shape
and extent of the former pond.
A fine brick bridge, faced in ashlar, spans the stream outside the monument at
its western corner. This is believed to have been built by General Beresford
in the early 19th century. Bedgebury Forge was situated about 1km to the north
west of the furnace. The forge was substantially destroyed by the subsequent
construction of a railway and Forge Farm house, and is not therefore included
in the scheduling. A moated site, with possible historical connections with
the ironworks, is situated about 100m to the north west of the monument, and
this is the subject of a separate scheduling.
The field to the south east of the dam was used for the cultivation of hops
during the mid-20th century and some of the concrete anchor points, used to
secure the hop wire at ground level, remain set into the bank. These are
excluded from the scheduling, along with the remains of redundant fencing,
although the ground beneath and around these features is included.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
