Reasons for Designation
The tungsten industry is defined as the mining, ore-processing, smelting and
primary processing of tungsten. The main ores of tungsten are wolfram and
scheelite, with the former being the more important. Both ores occur as vein
minerals, normally in association with the tin ore cassiterite. In England the
tin-producing areas of Cornwall have been the main producer of tungsten, but
production has also come from the Tavistock-Plymouth area of Devon and from
the Carrock Fell area in Cumbria. Tungsten production has largely been a 20th
century phenomenon, prior to this tungsten ores were regarded as an
undesirable contaminant of tin ore. In an effort to remove wolfram from tin
ore a chemical technique known as the Oxland Process was developed in 1850 and
the residue, sodium tunstate, was used in the textile industry, however,
production was very small. Demand for tungsten increased rapidly from about
1900 with the development of alloy steels required for armaments manufacture.
Tungsten also began to be used as a filament in electric lights and x-ray
tubes and as the 20th century progressed it became important in the nuclear
industry where it is used as a cladding for fuel rods containing uranium and
plutonium oxides. It is also widely used in cemented carbides and tool steels.
The 19th century Oxland Process is of importance as an early application of
chemical processing for metal extraction and all surviving site evidence
should be protected. The 20th century prospecting, mining and processing of
tungsten has left a range of surface features which form an important aspect
of the mining industries. A sample of sites should be protected covering a
range of the site evidence; in many cases these sites will show
tungsten-related features as the latest phase of a multi-period and
multi-metal mining landscape.
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.
Copper mining has spanned nearly four millenia of mining history from the
early Bronze Age (c.2000 BC) until the early 20th century, and British
production was important on a European scale in the 18th and early 19th
centuries and may also have been of European importance in prehistory. Over 50
copper industry sites have been identified as being of national importance.
This selection of nationally important monuments, compiled and assessed
through a comprehensive survey of the copper industry, is designed to
represent the industry's chronological depth, technological breadth, and
regional diversity.
The arsenic industry is defined as the mining, ore-processing, extraction and
refining of arsenic, to produce pure arsenic and other arsenic compounds.
Several arsenic bearing minerals occur but economic production has been
confined to the richer deposits of arsenopyrite. Arsenic production in
England has been virtually confined to the south west, particularly west
Cornwall and the Tamar Valley, minor production is also recorded from Carrock
Fell mine in Cumbria. The first known use of arsenic in Britain was as an
alloy with copper during the Bronze Age, however, it is not known if this
represents deliberate addition or merely accidental use of arsenical copper
ore. Arsenic calciners were developed well before any known mining of arsenic
as a means of eliminating arsenic from tin ore. Extraction of arsenic in its
own right began in Cornwall in 1812 and the industry expanded rapidly and
peaked in the later 19th century. From the late 1890s demand became erratic
and the industry gradually declined with production finally ending in the
1950s. The uses of arsenic were varied and included alloying with various
metals (notably lead for shot-making), for clarifying glass, for medicinal
purposes, for the production of pigments in paint and wallpaper, and for a
wide range of pesticides. The 19th and early 20th century prospecting, mining,
and processing of arsenic has left a range of surface features which form an
important aspect of the mining industry. A sample of sites should be protected
covering a range of the site evidence; in many cases these sites will show
arsenic-related features as the latest phase of a multi-period and multi-metal
mining landscape.
Carrock Fell tungsten mine and its early 20th century mill survives well. It
is the only example of a tungsten mine outside Cornwall and contains a diverse
and exceptionally impressive range of surface features. Additionally buried
remains of the earlier lead, copper and arsenic mines considered to have
occupied the same area as the tungsten mine will survive beneath the later
spoil heaps.
Details
The monument includes Carrock Fell tungsten, lead, copper, and arsenic mines
and the remains of an early 20th century tungsten mill, together with a number
of associated features including adits, stopes, opencuts, shafts, spoil heaps,
machine beds, trackways and a dam. It is located on either side of the
steep-sided valleys of Grainsgill Beck and its tributory Brandy Gill.
Documentary sources indicate that a little lead and copper mining was
periodically taking place in the Brandy Gill area during the 16th and 17th
centuries. In 1852 F.W.Emerson began mining for lead and copper but a dispute
over ownership of mineral rights forced him to abandon these workings and
instead turn to a wolfram vein - a mineral of tungsten - now named Emerson
Vein, east of Brandy Gill. This was a short-lived enterprise which was soon
abandoned. During the late 19th/early 20th centuries lead was occasionally
mined here, however, these workings were on a very small scale and most are
now lost beneath the spoil of the later tungsten mines. In 1906 the mine was
taken over by two Germans, William Boss and Frederick Boehm who appreciated
the value of tungsten in the growing armaments industry. It was during this
period that a small amount of arsenopyrite, a mineral of arsenic, was also
mined. The Germans ceased working here in 1912 and the following year the mine
was re-opened and worked until the end of the First World War when demand for
wolfram fell. The mine remained closed until 1942 when a tungsten shortage
during World War II led to the Ministry of Supply re-opening the mine
for just over a year. Mining began again in the 1970s and continued until
1981.
There are five mineral veins of importance at Carrock Fell; from west to east
they are the Wilson, Smith, Harding, Waterfall and Emerson. All run
approximately north-south and two, Harding and Emerson, extend south beyond
Grainsgill Beck. The Emerson Vein was the first to be worked and produced a
large amount of wolfram. The old workings had long been abandoned but 20th
century workings concentrated on exploration to locate the vein in new ground.
The Harding Vein was the most productive, yielding both wolfram and scheelite,
another tungsten ore. South of the beck the old stopes or surface workings
were worked out and some have subsequently been used as a dump for mill fines
sludge. To the north of the beck, however, it was worked up until the mine's
closure in 1981. The early workings on the Smith Vein were for arsenopyrite, a
mineral of arsenic, however, much of the mining at this vein is quite recent
with tungsten ore being found north of the beck. The Wilson and Waterfall
Veins, along with the modern Emerson workings, were merely the subject of
prospecting. The lead vein runs approximately north west - south east just to
the north of Grainsgill Beck.
The surface features of the mining at Carrock Fell are extremely impressive.
On the south bank of Grainsgill Beck there are the remains of Harding Vein, an
opencut following the line of the vein almost vertically up the steep
hillslope, with intermittent shafts and spoil heaps along its course, each
with a trackway leading down from it. By the side of the beck stands the
remains of the tungsten mill and associated buildings built in 1913 on the
site of an earlier mill. This later mill was equipped with hand-picking belts,
crushing rolls for breaking the ore to gravel size, jigs for shaking seives
for processing the ore, screens for grading ore particles by size, and Deister
sand tables, Wilfrey tables and vanners for sifting the fines. The
concentrates were roasted in half-ton capacity hand-raked furnaces and power
was supplied by generators driven by pelton wheels, assisted during water
shortage by gas engines. Amongst the ruined structures are a pipeway which
provided water power to drive the pelton wheel, kiln-like structures
considered to have been connected with power generation, and numerous concrete
machine beds. Immediately above the mill are the remains of a bouse team or
ore bin whilst to the east are a number of features including a trackway,
spoil heaps, a leat and pond, and the foundations of a stone building of
uncertain function.
On the north side of Grainsgill Beck there are the surface remains of many
examples of ore extraction including open workings, adits, prospecting
trenches, trials and spoil heaps on all of the five main wolfram veins
together with a series of trackways zig-zagging down the hillside. In Emerson
Vein, just north of the beck there are the remains of a three-roomed
stone-built structure of uncertain function. Elsewhere there are two bridges,
one of stone and concrete construction over Grainsgill Beck, the other a more
substantial construction partly hidden by spoil over Brandy Gill just above
its confluence with Grainsgill Beck. Higher up Brandy Gill there are the
remains of a dam.
The surface of the old mine track, now a walker's path north of Grainsgill
Beck, is excluded from the scheduling although the ground beneath it is
included.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
