Reasons for Designation
Approximately 10,000 lead industry sites are estimated to survive in England,
spanning nearly three millennia of mining history from the later Bronze Age
(c.1000 BC) until the present day, though before the Roman period it is likely
to have been on a small scale. Two hundred and fifty one lead industry sites,
representing approximately 2.5% of the estimated national archaeological
resource for the industry, have been identified as being of national
importance. This selection of nationally important monuments, compiled and
assessed through a comprehensive survey of the lead industry, is designed to
represent the industry's chronological depth, technological breadth and
regional diversity.
The ore works were an essential part of a lead mining site, where the mixture
of ore and waste rock extracted from the ground were separated (`dressed') to
form a smeltable concentrate. The range of processes used can be summarised
as: picking out of clean lumps of ore and waste; breaking down of lumps to
smaller size (either by manual hammering or by mechanical crushing); sorting
of broken material by size; separation of gravel sized material by shaking on
a sieve in a tub of water (`jigging'); and separation of finer material by
washing away the lighter waste in a current of water (`buddling').
The field remains of ore works include the remains of crushing devices,
separating structures and tanks, tips of distinctive waste from the various
processes, together with associated water supply and power installations, such
as wheel pits and, more rarely, steam engine houses.
Simple ore dressing devices had been developed by the 16th century, but the
large majority of separate ore works sites date from the 18th and 19th
centuries, during which period the technology used evolved rapidly.
Ore works represent an essential stage in the production of metallic lead, an
industry in which Britain was a world leader in the 18th and 19th centuries.
Sites are common in all lead mining areas and a sample of the best preserved
sites (covering the regional, chronological, and typological variety of the
class) will merit protection.
The two Rotherhope ore works include important remains dating to two
separate periods. The Vieille Montagne works is the best preserved mechanised
ore dressing plant known nationally, with the foundations for a range of ore
processing equipment retaining important technological information surviving
within the remains of purpose built buildings. These remains complement
those at Middle Level, where the exposed timbers indicate good stratigraphic
survival of equipment dating to the early 19th century. Most of the ore
processing techniques employed in this earlier period were manually powered
and labour intensive, and were often conducted in the open air. The remains at
Middle Level will also retain important technological information.
Details
The monument, which is divided into two areas, is situated on the north east
side of Rotherhope Fell above Black Burn. It includes the ruined structures
of the lead ore and fluorspar processing plant built by the Vieille Montagne
Company in the early 20th century, together with the earthwork and buried
remains of a pre-1850s ore works and associated lead mining remains at
Rotherhope Middle Level. It does not include the standing and earthwork
remains of Black Burn Level and the extensive areas of ore processing waste
besides the burn, as much of the context of these features has been lost
through demolition of structures and removal of waste for reprocessing and
use as hard core. The remains of Rotherhope High Level, scattered air shafts
and the extensive water management system that extends across the fellside
are also not included in the scheduling. However, all deposits of mining and
ore processing wastes, within the areas of protection, are included.
The mineral rights to Rotherhope Fell were owned by Greenwich Hospital which
in 1764 appointed the engineer John Smeaton to act as a surveyor to fix
boundaries for the various mineral leases. In the late 1770s he laid out a
number of long levels designed to exploit the veins at greater depth.
This included the Black Burn Level (later known as Rotherhope Fell Low Level)
which was driven south eastwards from just above the Black Burn stream. This
level was the main working entrance to the mine from c.1850 when the Middle
Level ore works became disused and a new plant was built c.250m north east of
Black Burn Level. Middle Level was maintained as the tail race for underground
hydraulic engines. In 1907 the mine was taken over by the Vieille Montagne
Company which rebuilt the Low Level ore processing plant in 1912. This plant
was highly efficient and worked at nearly full capacity, processing ore from
both Rotherhope and Haggs mine until closure in 1930. Re-opened in 1935 the
mill eventually closed with the closure of the mine in 1947.
Middle Level is thought to pre-date Smeaton's Black Burn Level. The portal and
a c.30m length of the level has collapsed. This portion of the level was
constructed by cut and cover (where, to maintain a constant gradient, the
level passed though soft ground before reaching solid bedrock, a trench was
dug, stone vaulting built and then covered over with earth to stabilise the
construction). This section will retain evidence of the level's construction
and is included in the scheduling. To the east of the level there are the 0.5m
high earthwork remains of a range of small buildings. Extending from the level
mouth there is a tramway leading to a spoil heap over 200m long and up to 8m
high. This lies to the west of an extensive area containing buried and
earthwork remains of an early 19th century ore works which includes numerous
timber and stonework remains. At the southern (uphill) end of the works
(opposite the start of the mine spoil heap) there are the mainly buried
remains of a set of bouse teams (stone built bays for unprocessed ore).
Approximately 50m to the north, extending for a further c.60m, is a low (0.5m
high, 4m-5m wide) earthwork dam. This has been breached at its southern end
and has a sluice to the north which feeds to a 20m square area of timber and
metalwork remains, mostly buried in dressing (ore processing) waste.
These remains include a 3m by 6m wooden frame including eight pairs of 0.3m
by 0.3m square timbers which is interpreted as the base for a set of
jiggers (equipment using water to separate gravel sized particles of lead
ore from less dense waste material). Footings, up to a maximum of 1m
high, survive of a 6m square stone-built building, and c.20m to the south
east and at the north end of the area of scheduling there are the low remains
of a second stone building c.3m square. The whole area between this second
building and the bouse teams at the southern end of the ore works, and
bordered to the west by the mine spoil heap and to the east by the dam and
trackway, retains earthwork and structural remains of numerous features,
together with spreads of dressing wastes. Exposed sections of timberwork
demonstrate good in situ survival of features relating to the ore works and it
is considered that the buried remains will provide evidence of early 19th
century ore processing techniques. Spreads of dressing wastes continue
downhill from the 3m square building remains, but these deposits appear to be
more seriously disturbed and have thus not been included in the scheduling.
The structural remains of the later ore processing plant operated by the
Vieille Montagne Company in the 20th century form a second area of
scheduling, c.0.8km north east of the Middle Level ore works. Included in
the scheduling is a 30m long sample section of the 1m-2m wide leat that
supplied water via a 1m diameter iron lined shaft and pipeway to a
waterwheel and water powered turbine sited on the north west side of the
main building. The wheelpit survives as a 12m by 2m stone-built structure
standing to 2m high. Just to the north east of the end of the leat are the in
situ remains of part of a 0.5m diameter iron pipeway which fed water to
a pelton wheel sited in the main building. Pelton wheels were waterpowered
turbines used to produce electricity. The main building mostly survives to
eaves level; it is two storied (but with a high roofed first floor) and mainly
built in rubble stone, with the northern portion built in rendered brickwork.
Well lit by large windows, it measures c.35m by 8m and is oriented north east-
south west. It retains evidence that the building was extended at least once
during its lifetime, and part of the building is believed to be the remains of
the first dressing mill built in the late 19th century. At the north and south
ends, extending from the south east wall, the building extends south westwards
forming two bays c.8m and c.12m wide, extending 4m and c.12m respectively. The
floor of the building retains a large number of substantial concrete bases for
ore processing equipment. Most of the machines are believed to have been
jiggers (a jigger consisted of a sieve containing ore crushed of a uniform
size which was agitated in a tank of water to separate the heavy ore from the
lighter waste).
The northern bay has a 3m square steel frame and brick panel tower adjacent to
the south east wall which is linked to a terrace to the rear of the main
building by a flatbed bridge c.2m wide, 6m long, constructed out of 0.3m
square timbers. The tower is partly filled with fine ore processing
material which fed to the ground floor of the northern bay via a timber chute
which still survives in situ. Extending to the north west at the southern end
of the main building, is a 13m by 8m breeze-block built single storey shed
with a corrugated iron roof still in place. This retains the concrete bases
for an oil tank and coal oil engine installed in 1927-8, to supplement and act
as standby to the hydraulic power system. Immediately to the north east of
this shed are the concrete bases of further ore processing machinery which
would have filled a c.12m by 11m building. These are thought to date to after
the reopening of the plant in 1935. A further area of machinery bases fills an
8m wide area extending 35m north east from the main building. These bases were
contained within a single storey building built after 1912, and operational by
1927, and were for a number of Wilfly and circular tables. These were slightly
inclined tables upon which gentle streams of water containing fine particles
were directed. Working in a similar way to buddles, which were commonly used
in the 19th century, they were used to retrieve very fine particles of ore,
which having a higher density than the waste material, settled first,
towards the top of the inclined surface. Just beyond the remains of this
building, to the north east, there is a 2m high stone revetment wall and the
footings of further ancillary buildings which included a weigh house and
store.
The corrugated iron hut within the southern area of protection (just to the
north of Middle Level) is excluded from the scheduling but the ground beneath
is included.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
