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.
Nucleated lead mines are a prominent type of field monument produced by lead
mining. They consist of a range of features grouped around the adits and/or
shafts of a mine. The simplest examples contain merely a shaft or adit with
associated spoil tip, but more complex and (in general) later examples may
include remains of engine houses for pumping and/or winding from shafts,
housing, lodging shops and offices, powder houses for storing gunpowder, power
transmission features such as wheel pits, dams and leats. The majority of
nucleated lead mines also included ore works, where the mixture of ore and
waste rock extracted from the ground was 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
sizes (either by manual hammering or 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 vary widely and 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.
The majority of nucleated lead mines with ore works are of 18th to 20th
century date, earlier mining being normally by rake or hush and including
scattered ore dressing features (a 'hush' is a gully or ravine partly
excavated by use of a controlled torrent of water to reveal or exploit a vein
of mineral ore). Nucleated lead mines often illustrate the great advances in
industrial technology associated with the period known as the Industrial
Revolution and, sometimes, also inform an understanding of the great changes
in social conditions which accompanied it. Because of the greatly increased
scale of working associated with nucleated mining such features can be a major
component of many upland landscapes. It is estimated that several thousand
sites exist, the majority being small mines of limited importance, although
the important early remains of many larger mines have often been greatly
modified or destroyed by continued working or by modern reworking. A sample of
the better preserved sites, illustrating the regional, chronological and
technological range of the class, is considered to merit protection.
Barytes and zinc are normally found as vein minerals in association with lead.
Economic deposits of barytes have been found in all the major lead orefields
except the Mendips whilst economic deposits of zinc have similarly been found
in all the major lead orefields other than the Yorkshire Pennines. The mining
of barytes and zinc has not differed from contemporary mining of other vein
minerals, hence the surface features of these minerals largely parallels those
of lead mining. The dominant period of barytes extraction was the late 19th
and 20th centuries, thus barytes mines tend to be of later date than most lead
mines. Similarly zinc mining increased markedly in scale during the late 19th
century as the demand for lead and copper fell, thus the zinc industry is
relatively rich in late 19th and early 20th century features. Amongst other
things barytes is used in paint manufacture, as a drilling lubricant, and as a
filler in the cloth and paper industries. Zinc is used in paints, to make dry
cell batteries, and for galvanising iron to prevent rusting.
Prehistoric cairnfields are concentrations of cairns sited in close proximity
to one another. They often consist largely of clearance cairns, built with
stone cleared from the surrounding landsurface to improve its use for
agriculture, and on occassion their distribution pattern can be seen to define
field plots. They were constructed from the Neolithic period (from about 3400
BC) although the majority of examples appear to be the result of field
clearance which began during the Bronze Age (2000-700 BC). The considerable
longevity and variation in size, content and associations of cairnfields
provide important information on the development of land use and agricultural
practices. Cairnfields also retain information on the diversity of beliefs and
social organisation during the prehistoric period.
Despite some quarrying for roadstone at the Low Force Workings, Force
Crag mines remain a relatively well-preserved extensive and impressive
19th-20th century mining landscape containing a wide range of mining
components including levels, a shaft, water management systems for powering
machinery, remains of transportation systems for moving ore around the
complex, settling tanks, remains of associated buildings, spoil heaps and
dressing waste. Of particular importance is the rare intact 20th century
barytes mill with in situ ore crusher and flotation plant which was used to
separate barytes from blende (zinc sulphide). This mill is considered to be
the best preserved barytes mill in the country, and thus highly representative
of its technology for the period. Overall the Force Crag mines are important
because they contain surviving traces of most of the episodes of industrial
activity on the site and enable the relationship of the extraction and
processing areas to the industrial landscape that supported them to be well
understood. Additionally the prehistoric cairnfield south of Coledale Beck
survives reasonably well and is a good example of this class of monument.
Details
The monument includes Force Crag mines and barytes mill, together with the in
situ machinery associated with the mill, and the remains of all associated
buildings, earlier mills, water management systems, settling ponds, trackways,
tramways, dressing areas and an aerial ropeway. These features are located
over a large area at the foot, either side, and above Force Crag at the head
of the Coledale Valley, and incorporate both Low Force Workings and High Force
Workings. Also included in the scheduling is a prehistoric cairnfield situated
on the hillslope south of Coledale Beck.
The earliest date when mining began at Force Crag is unknown, however,
documentary sources indicate that small scale surface extraction of lead had
taken place by 1578 and that further trials were being undertaken in the
vicinity during the mid-18th century. More comprehensive records indicate that
the site was mined for lead from 1839 until 1865, and for barytes and zinc
intermittently from 1867 until it was finally abandoned in 1991. The extant
mill building was built in 1908-9, redesigned in 1939-40, and contains
considerable in situ ore-refining machinery that was in use during the 1980s.
High Force Workings lie on the steep fellside north east and west of Pudding
Beck. The highest of these workings includes a line of small prospecting pits
located to the west of Pudding Beck, and a line of stopes - ie larger open
cast areas from where the vein has been removed - on the opposite side of
Pudding Beck. Close by these stopes is Level 7 located at NY19352163, the
highest of the Force Crag adits. A short distance downslope lies Level 6,
situated at NY19242148. It is located close to the western end of a long
artificial platform or terrace that terminates adjacent to the ravine down
which High Force flows.
Also located on this platform are three buildings of uncertain function. A
concrete-lined chute leads down from this platform to a lower platform which
functioned as the terminal for an aerial ropeway constructed in 1941 to
transport ore down to the Lower Force mill. This aerial ropeway replaced a
track originally constructed to transport the ore. Large spoil heaps lie below
the platforms, and further downslope, at NY19402147, lies Level 5. Level 4,
the easterly of the High Force Workings, is located at NY19472164 at the head
of a natural gully. Other features at the High Force Workings include
the bases of aerial ropeway pylons and a small brick building of uncertain
function.
Low Force Workings cover an extensive area at the foot and either side of
Force Crag. Close to the foot of the natural gully containing Level 4, and
centred at approximately NY19692166, are a cluster of workings comprising a
number of small surface extraction pits, Milkhouse Level, The Old Shaft and
Level 3, together with the remains of two small dams. Nearby are features
identified as tramways, and a chute or slushing channel for carrying ore
downhill along wooden channels using water. Level 2 lies at NY19762158 while
Level 1, the most intensively used of the Low Force Workings, lies at
NY19892163. The original entrance to level 1 was abandoned in 1967 and a new
entrance cut a short distance to the north east at NY19922165. A length of
tramway runs between the two entrances upon which a locomotive shed remains.
The lowest and most easterly of the Low Force adits is Level 0 located at
NY20122173; adjacent is a second locomotive shed.
Associated with all these levels are a complex series of at least 14 tracks
and four tramways along which the ore was transported. Fragments of slushing
channels which carried ore from Levels 4, 3 and 2 also survive. Also visible
are a number of pylon bases which supported the aerial ropeway, together with
the base and some metalwork of the midway station located at NY20202201 where
the ropeway turned an acute angle before descending to the lower terminus at
NY19922157.
Three ore processing mills are known to have existed at Force Crag. The first
water wheel which would have powered a simple crusher consisting of two iron
rollers had been erected by 1839. In 1854 a new mill was built on the southern
bank of Pudding Beck at NY19812150. Roadstone quarrying in 1961 and subsequent
dumping destroyed much of the area surrounding the mill but faint traces of
the possible wheel pit and a wall survive. Nearby there is a mound of mill
tailings and waste products from the ore washing process, together with the
buried remains of a building associated with this mill. A second mill was
built on the northern bank of Coledale Beck at NY20242177 sometime before
1861. The wheel pit is well-preserved as an earthwork as is the tailrace.
Structural foundations also survive together with traces of a timber settling
tank. A third mill was built on the site of the extant mill building at
NY19972163 in about 1906. This was replaced with a new building in 1908-9 but
it fell into disrepair during the 1920s. The mill was rebuilt in 1939-40 and
used intermittently until final closure in 1991. Survey of the mill has
revealed seven phases of building development between 1908-9 and about 1984.
Many of the items of machinery in use during the mill's latter years were
initially removed after the mine closed in 1991. They have subsequently been
acquired by the National Trust and returned to the building, although not all
to their original positions. Of particular importance here is the survival of
an in situ ore crusher and the flotation plant which was used to separate
barytes from blende (zinc sulphide).
Other surviving buildings associated with the mine workings include an office
built in front of the mill in about 1960, and an explosives store located at
NY19872142 which was built before 1861 and rebuilt in about 1908.
Water power was provided via a complex system of reservoirs, dams, leats and
cisterns. A total of eight dams were constructed across Coledale Beck, two of
its tributories, and the minor stream flowing down the gully above Level 3.
These provided reservoirs of varying sizes. Additionally at least 16 leats
channelled water around the mine workings. Remains of three cisterns lie to
the north, east and west of the extant mill.
On the north bank of Coledale Beck are a number of settling ponds. The first
are thought to have been built in about 1907 and formed a total of six
adjoining ponds located at NY20022160. These were later modified then
eventually filled in. Another settling pond is located a short distance to the
east at NY20122164 and remains waterlogged.
In addition to the small spoil tips outside the entrances to the levels there
are three much larger spoil tips; one defined by the confluence of Coledale
Beck and Pudding Beck, one south west of the extant mill, and one south west
of Level 0.
Remains of three small rectangular huts, two lying south of Coledale Beck and
one lying close to the confluence of Coledale Beck and Pudding Beck, are of
uncertain function but are interpreted by the surveyor as of late 19th century
date and perhaps associated with the mining operations.
A prehistoric cairnfield is situated on the hillslope between the confluence
of Coledale Beck and Birkthwaite Beck centred at NY20232166. It consists of at
least 33 oval-shaped stone mounds between 1.8m to 4.5m in diameter and up to
0.3m high. Four of the cairns appear to have been levelled and enlarged at
some later date to form the floors of temporary shelters.
All fence posts and the areas of roadstone quarrying are excluded from the
scheduling, although the ground beneath these features is included.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
