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 is a vein mineral normally found in association with lead deposits,
particularly in the North Pennines. The dominant period of extraction was in
the late 19th and 20th centuries and a high proportion of its extraction has
come from former lead mines, either by renewed underground workings or
re-processing dumps, barytes having been discarded as gangue or waste rock.
Processing of barytes was relatively simple and involved crushing, jigging,
drying and grinding at a mill into a powder. The chief uses of barytes have
been as a cheap, inert white filler in the manufacture of paper and paint and
more recently it has been used as the basis for barium chemicals.
The remains of the extensive lead exploitation industry at Grassington
represent the most highly organised and compact mining landscape in the area.
Significant remains of a range of industrial processes survive well. These
include evidence of a number of important technological innovations,
particularly the introduction of wire rope and large scale rodway power for
pumping and winding and an extensive intergrated water management system. The
monument also demonstrates a highly organised and centralised system of
management and introduced new professional management techniques on a large
scale which replaced the earlier traditional system. Evidence of this
customary law of the 17th and 18th centuries is preserved in the survival of
meer stones marking out land allocations. The barytes mill at Grassington
retains important remains of the grinding processes involved and is important
in illustrating the change from lead to gangue-mineral mining. The Grassington
Moor lead mining landscape offers important scope for understanding the
development of a major lead mining landscape and the technological, economic
and social developments of a major site in the industrial revolution.
Details
The monument includes the most important remains of the extensive lead
workings on Grassington Moor. It is located on the hillside to the north east
of Grassington and occupies areas of open moorland, semi-moorland and old
enclosed land.
The remains include mine workings, ore processing works, ruined buildings,
other structures and waste tips, and the remains of a complex system of
ropeways and rodways that powered machinery in many different extractive and
processing operations throughout the area. Part of the extensive water
management system is also included in the scheduling. The monument is divided
into ten separate areas of protection which include the core extractive and
processing areas, some individual mines, and areas where evidence of early
extraction and prospecting is preserved. Further remains of the lead industry
lie beyond the monument, but are not included in the scheduling.
The lead ore at Grassington Moor is located in two bands extending north west
to south east with the extraction and processing concentrated primarily in
three areas, Grassington Moor (formerly known as Out Moor), Yarnbury and
Hebden Gill.
To the north, the monument occupies a large area of Grassington Moor, where
remains of mine shafts and shallow workings which exploited ore near to the
surface are located. Within the eastern area of the monument, on Grassington
Moor, are remains of later mines and processing works at Coalgrovebeck and the
Cupola Mill complex on the rising south west slopes of the moor at Bank Head.
Further isolated mines are located to the north. To the south west in the
enclosed area known as New Pasture there is a steep valley of New Pasture
Beck, which downstream becomes Hebden Gill. The valley separates the two bands
of lead ore so there are few lead workings present, although there are remains
of a water course which is included in the scheduling.
South of the New Pasture boundary wall is the Yarnbury area where shaft mining
and processing took place. The workings here extend for about 1.4km north west
to south east following the line of the ore. The workings include a series of
mines and processing plants with Yarnbury at the west and Cockbur to the east.
The third area of workings included in the scheduling is to the south east of
Yarnbury, which occupy steep sided Hebden Gill and Bolton Gill.
The first known exploitation of lead at Grassington was by the 4th Earl of
Cumberland in the early 17th century, although it is thought that some
primitive extraction and smelting had taken place earlier. The early
exploitation involved the digging of shallow shafts along the vein. The first
mill to process the Grassington lead ore was the Low Mill built in 1605. This
lies outside the area of the monument at Brow Well on the banks of the River
Wharfe, some 5km to the south. A second mill was built on the edge of the moor
probably near Cupola Corner in 1637, although this had closed by 1650.
Production continued on a small scale until around 1680, when changes were
made to the process of allocating mining grounds or meers, after which miners
usually worked in small partnerships, with investors providing capital. These
mines were typically small with shafts rarely more than 23m deep. Mining
spread onto the moor soon after 1731 and exploration continued steadily
throughout the 18th century. By the 1750s larger mines such as those at
Coalgrovehead began to appear, dominated by wealthy individuals. Production
was high and the Low Mill was expanded in 1754 and Moor Mill was built at
Cupola Corner in 1756. In 1774 the customary law governing the allocation of
land was changed again and the meer system replaced by the granting of leases
by the mineral lord. Larger output led to mechanised winding and, as shafts
became deeper, to the pumping of surplus water.
By the end of the 18th century, production was stagnating and many mines had
reached the water table but were generally too small to afford the cost of
pumping. In an attempt to solve the problem, the owner of the mineral rights,
the 5th Duke of Devonshire, started the construction of the Duke's Level in
1796. This was a tunnel driven from Hebden Gill at the south east and
extending for a distance of almost 2.5km below the shafts at both Yarnbury and
on the moor. The Duke's Level was initially 3.5m high and 1.9m wide and was
also designed as an underground canal to move waste rock and ore from the
mines. Although started in 1796 the tunnel was not completed until 1830 when
it reached the Coalgrovebeck mine on the moor. By this time the tunnel had
been reduced in size and was only being used for drainage; the cost of a large
tunnel to carry a canal had become prohibitive. A major development occurred
in 1792 when the Cupola Smelt Mill was built on the site of the now redundant
Moor Mill. This used two coal-burning reverberatory furnaces, replacing the
earlier peat fired mill. The Cupola Mill also had an slag hearth for smelting
slag which was built into the fabric of the earlier mill.
Despite these measures output continued to fall. In 1818 John Taylor, one
of the emerging professional mining engineers, was appointed Mineral Agent
for the 6th Duke of Devonshire. Under Taylor's stewardship there were
improvements in pumping and winding and new centralised dressing floors were
built which were linked to the tops of the principal shafts by roads and
railways. Further improvements in technology and efficiency were made over the
following years. One of the most significant new operations was a large water
powered wheel known as the Brake House Wheel built in 1821 to the north east
of the Cupola Mill. This powered a system of rods, levers and rope to provide
pumping and winding for several separate mines in the north of the moor. This
wheel was powered by water running through a channel known as the Duke's High
Water Course which led from a complex of reservoirs at Blea Beck to the east.
There were three reservoirs built between 1821 and 1826, connected by
overflow sluices that provided water to different areas of the mines. A second
channel, known as the Duke's Low Water Course, led off Blea Beck south of the
reservoirs. The two water courses extending from the dams over Sand Haw are
not included in the scheduling. The 1820s also saw the building of the High
Grinding Mill 400m north east of Cupola Mill. Further changes from the 1830s
included the introduction of hydraulic stamps and buddles at the High Grinding
Mill and dressing floors at Coalgrovebeck and the construction of the High
Winding House to pump and wind at the Coalgrovehead shaft. Major changes were
also made to the Cupola Smelt Mill with the construction of a slag hearth in
1840 and a new furnace in 1858. In 1849 the two mill chimneys were demolished
and replaced by a 500m straight flue with condenser and chimney. A 550m loop
and second condenser was built around the chimney in 1852.
Once the Duke's Level was completed mines on the moor were self draining,
making the Brake House Wheel redundant for pumping. However, it was modified
by the addition of winding drums, fitted with wire ropes, which replaced the
horse whin for hoisting within shafts. A total of seven shafts were served by
the Brake House wheel for winding. Wire rope was an innovation introduced
during the 1840s and was superior to hemp as it was stronger and stretched
less.
At the same time as the developments on the moor new shafts were sunk at
Yarnbury to meet the Duke's Level, a branch of which (called the Black Drift)
was being driven through the area. A railway system and a network of properly
drained roads was built between the major shafts and processing works. The
Duke's New Road was built in 1827 to connect the Yarnbury mines to the
moor. Developments at Yarnbury also included centralised processing. This
involved the construction of dams connected by leats and the extension of the
Duke's Water Course following the contour for some 3km from Coalgrovebeck to
the New Wash Dam. This stored water for the Low Grinding Mill, built in 1824,
at the west side of the Yarnbury complex. By 1826, a stamp mill was
incorporated and other dressing floors built at Beevers Mine. Because water
was scarce at the Yarnbury mines only three shafts were fitted with water
powered pumps, the remainder being powered by horse whims.
There was further exploitation of the Yarnbury lead veins to the south east
at Bolton Gill and Hebden Gill. At Bolton Gill there was a shaft connected by
rods to a large wheel located adjacent to Hebden Gill. The ore from this mine
was sent via an early aerial ropeway to a smelt mill located on the east side
of Hebden Gill Ore. Further south, adjacent to the entrance to the Duke's
Level, was a small dressing floor.
Lead continued to be exploited on Grassington Moor for the most of the century
with further developments including another winding house built in 1855 north
of the High Grinding Mill and the extension of the wire rope winding gear to
other shafts. However, from the mid-1840s onwards shafts began to close on
both the Moor and at Yarnbury and in 1882 the last lead mine was abandoned.
In 1918 lead mining was re-started and a small plant was built at
Coalgrovebeck and a shallow shaft re-opened. Despite switching to the
reclamation of barytes from spoil tips the venture was unsuccessful and
production ceased in 1927. The 1940s saw the moors used for military training
and an army firing range. Industry returned in 1955 when a large barytes mill
was built on the site of the High Grinding Mill.
The remains of the Grassington Moor lead workings include several areas of
early rake workings where open cast mining followed the ore bearing veins.
These areas are located mainly in the northern part of the monument, and the
remains are preserved as open scars and shallow shafts.
On the open moor the remains include many individual mines which survive as
shafts surrounded by spoil tips; these often include the remains of whim
circles for horse powered winding and evidence of primary sorting and dressing
located nearby. These mines are linked by tracks and in some cases remains of
leats and dams also survive. At the centre of the main area around
Coalgrovebeck are the remains of the centralised processing and mechanization
functions. The Cupola smelt mill survives as a ruin and the form and function
of the main features such as the furnaces and wheel pit are still discernible.
To the rear of the mill the flue system survives almost completely and
includes the stone arched flue itself, condensers built into the line of it
and the chimney which stands to its full height. North of the mill are the
remains of the Brake House wheel pit and part of the superstructure. The
system of rods and wire rope which the wheel powered can still be traced
throughout the monument with the survival of stanchion bases which supported
it. Further structures associated with the centralised functions of the mines
such as the high grinding house and the dressing floors still survive as ruins
and buried remains. The high crushing mill was incorporated into the 20th
century barytes mill and remains of it can still be identified amongst the
later building. The barytes mill re-used the existing stone building with some
additions of re-used stone and concrete. Remains of further processing
structures such as the 17th century High Mill and the late 18th century Moor
Mill will survive as buried remains.
At Yarnbury there are remains of the mining features, as evidenced by shafts
and shallow shafts and the early 19th century buildings and water courses
associated with ore processing. Throughout this area, partly obscuring some
remains, are the waste tips derived from mining and ore processing. The
remains of the processing works survive as low walls and floors from the
grinding mill and settling tanks. The complex of water management survives
well and the Duke's Water course is preserved as a substantial channel leading
to a reservoir which provided a head of water for the grinding mill and other
structures in the area. Remains of further leats and channels can be
identified and to the north east is the portal to the Yarnbury incline. This
survives as a stone faced arch inscribed with the date 1828 and is Listed
Grade II.
Further to the south in Hebden Gill, the entrance to the Duke's Level and the
adjacent dressing floor survive. Further north along the gill side are the
substantial ruins of the ore processing works which include well preserved
settling tanks, washing floors and a wheel pit as well as the entrance to adit
mines. The Bolton Gill mine shaft, winding wheel pit and associated structures
survive along the side of Hebden and Bolton Gill. On the hillside east of
Hebden Gill are the surviving remains of shallow shaft mounds, adit mines and
the stone footings for the pillars which supported the early aerial ropeway
which carried ore to the Hebden Gill dressing floors.
Throughout the monument stones known as meer stones which marked the extent of
the customary law mining allocations still survive, some in their original
locations and others re-used in field walls. These are often inscribed with
dates and owners names. Further meer stones lie outside the area of the
scheduling.
To the east the three dams on the Blea Beck survive as substantial stone
revetted earthen banks up to 20m wide at the base and 10m high and are
included in the scheduling.
Throughout the monument are remains of other structures such as stores,
workshops, workers cottages and other ancillary buildings. There are also
large areas of substantial spoil tips and waste material from mining,
processing and re-processing. This serves to obscure some features,
although archaeological features will be preserved beneath this material.
Also included in the scheduling is a stone built lime kiln, situated to the
west of Hebden Beck. This was used to convert or burn limestone into a lime
suitable for improving agricultural land and building purposes.
A number of features are excluded from the scheduling; these are all gates,
gate posts, signs, the surface of Moor Lane and the surfaces of all tracks
which cross the monument; the ground beneath all these features is, however,
included.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
