Details

The monument includes the core part of Eylesbarrow Tin Mine, together with
adjacent tin streamworks, earlier mining remains, archaeological remains
of prehistoric and historic date including a stone hut circle settlement,
pillow mounds and field systems situated on the southern slopes of
Eylesbarrow overlooking the valley of the River Plym. Tin extraction
within the area later to become known as Eylesbarrow Tin Mine probably
dates back to at least the 12th century, although it is not until the 16th
century that specific documentation is known. Some of the earthworks
visible within the monument will certainly be the result of mining
activity before the better documented phases of the 19th century. The 19th
century mine opened in 1814 and continued until 1852. During this time
several companies were formed to run the mine and most failed to make a
profit.

A large number of different types of earthworks and structures relating to
tin extraction and processing survive within the monument. Amongst the
earliest are two areas of streamworking, both of which have been damaged
by later mining activity. The streamworks were formed during the
extraction of tin deposits using water to separate the heavy tin from the
lighter silts, sands and gravels. Once the streamworks were abandoned, the
tinners turned their attentions to the lode tin within the area. The first
stage was extensive prospecting using both pits and trenches. Large
numbers of these features survive within the vicinity of the tin work. The
pits were excavated solely by hand but the trenches were formed by using
both shovels and running water. The water was brought to the area in leats
and stored in reservoirs. Once the lodes had been identified they were
extracted using different mining techniques. Foremost among these was the
use of opencast quarries known as openworks to extract the lode tin and
these survive as deep, steep sided gullys trending approximately east to
west. The second form of evidence relating to mining survives as series of
deep pits and these are known as areas of lode back tin working. This form
of exploitation consists of deep pits being cut onto the back of the lode
with the tin ore encountered being raised to the surface. When extraction
became difficult the pit was abandoned and a new one opened elsewhere on
the lode. The resulting archaeological remains include linear series of
deep pits each associated with a spoil dump.

While the earlier mining remains are of considerable significance,
Eylesbarrow's importance stems from its unrivalled array of 19th century
mining remains making it the largest and most informative example of a
large scale water powered tin mine in Britain. At least 27 shafts and five
adits were cut to reach the tin lodes, seven whim platforms and two water
powered engine wheels were built to power the lifting and pumping
machinery, a series of tramways were made to carry the ore to six separate
stamping mills and, to complete the picture, a smelting house was
constructed to smelt the processed tin from the stamping mills. The size
of the operation is further emphasised by the large number of ancillary
buildings constructed to serve the mine. Amongst these are a count house,
dormitory accommodation, blacksmith's shop, powder houses, sample house
and various storage buildings.

The smelting house is of particularly significance because it is the only
surviving example on Dartmoor and black tin from other mines was brought
here during its nine year life. It survives as a substantial rectangular
building containing a blast and reverberatory furnace. The house shares a
wheelpit with an adjacent stamping mill and the remnants of a flue lead
away upslope towards the remains of a chimney stack. During the nine years
that the smelting furnace produced tin metal a total of 276 tons (280
tonnes) were smelted. All the black tin produced at Eylesbarrow before
1822 and after 1831 was probably sent to Cornwall for smelting.

Peripheral archaeological remains associated with the mine include five
pillow mounds which were probably built by the miners to provide an
additional food source and two field systems in which tinners may have
grown crops or kept livestock. The only archaeological remains within the
monument which are in no way connected with tin working at Eylesbarrow is
a prehistoric settlement at SX59296823 which survives as an oval enclosure
containing five stone hut circles.

MAP EXTRACT
The site of the monument is shown on the attached map extract.
It includes a 2 metre boundary around the archaeological features,
considered to be essential for the monument's support and preservation.

Source: Historic England

Reasons for Scheduling

Tin has been exploited on Dartmoor since the prehistoric period and surviving
remains are numerous, well-preserved and diverse, with the two main types of
tinwork being streamworks and mines. The three different forms of tinwork used
to mine lode tin were lode-back pits, openworks and shafts. Lode-back pits
survive as shallow shafts which were sunk onto the lode outcrop to extract
cassiterite. These pits generally occur in linear groups following the line of
the lode, with associated spoil dumps. Many tin lodes have been worked at the
surface by digging pits onto the backs or surface exposures of the lode to
remove the mineral that lay above the water table. Openworks are also known as
beams and they were formed by opencast quarrying along the length of the lode.
The term openwork refers to the field evidence for opencast quarrying of the
lode, which produced relatively narrow and elongated gulleys.
Shaft mining is synonymous with underground extraction, with access to the
lode being through near vertical or horizontal tunnels known as shafts and
adits. Underground workings are often complex in character, with considerable
layout variations reflecting developing extraction techniques. Within the
vicinity of most mines are found the remains of prospecting activity. This
generally takes the form of small pits and gulleys. Some mines have associated
surface buildings which provided a variety of services for the working miners.
The ore quarried from all three forms of mine was taken for processing to
nearby stamping mills.
A national survey of the tin industry in England was completed in 1999. This
demonstrated the number and diversity of surviving remains and the
significance of some areas for understanding the origins and development of
the industry. Dartmoor is one such area and here a representative selection of
sites with significant surviving remains has been identified as nationally
important.

Eylesbarrow Tin Mine contains a broad range of different forms of evidence
relating to prospecting, exploitation and processing of both tin deposits and
lodes. In particular, the 19th century mining remains represent an important
source of information concerning the character of a large scale water powered
tin mine, where all the original elements survive in an excellent condition.
The survival of so many stamping mills together with a smelting house and full
range of mining remains and associated buildings is indeed unique in the South
West of England.

Source: Historic England

Sources

Books and journals
Butler, J, Dartmoor Atlas of Antiquities, (1994), 69
Newman, P, Eylesbarrow (Ailsborough) Tin Mine, Devon, (1999)
Newman, P, Eylesbarrow (Ailsborough) Tin Mine, Devon, (1999)
Newman, P, Eylesbarrow (Ailsborough) Tin Mine, Devon, (1999)
Newman, P, Eylesbarrow (Ailsborough) Tin Mine, Devon, (1999)
Newman, P, Eylesbarrow (Ailsborough) Tin Mine, Devon, (1999)
Newman, P, Eylesbarrow (Ailsborough) Tin Mine, Devon, (1999)
Newman, P, Eylesbarrow (Ailsborough) Tin Mine, Devon, (1999)
Other
English Heritage, NMR Monument Report - SX 56 NE 146, (2002)
MPP fieldwork by S. Gerrard, Gerrard, S., (2002)

Source: Historic England