Reasons for Designation
Electricity is generated by the motion of a wire coil within a magnetic
field, the motion being provided by a turbine driven by steam, water or
combustion. Early uses of electricity, for telegraph systems, lighthouses
and electrical devices in mines, followed soon after Michael Faraday's
discovery of magneto-electric induction in 1831. It was not until the
1870s, however, after technological developments in Britain, USA, Germany
and France, that electricity started to be used on a large scale, for
public lighting, industrial machinery and (by the 1890s) trams and
railways.
Early electricity generation took place in small isolated power houses,
often dedicated to individual country estates, wealthy urban housing
estates, industrial sites, hospitals or lighthouses. Most were coal fired,
but in rural areas there was also significant use of hydro-electrics. From
the 1890s, large central power stations were built to generate power for
transmission over wide areas to multiple users, although (as industry
adopted electricity more widely) some collieries, textile mills and steel
works built their own power houses. Fuel sources became more diverse,
including gas, hydro-electric and refuse destructor heat, but coal
remained the dominant fuel.
Electricity generating and distribution buildings of the 19th and early
20th century display a great variety of architecture and design. In the
countryside, existing buildings tended to be used, often water mills
adapted for hydro-electric use. In urban areas power houses were usually
purpose-built, and frequently in flamboyant and distinctive architectural
styles that reflected municipal or company pride, and made statements
about investment and technology as well as civic and commercial rivalry.
A period of rationalisation after 1919 led to the creation of the national
grid. Many of the smaller, isolated power stations were closed down in
favour of fewer, larger stations. The newly-formed Central Electricity
Board purchased electricity from both private and public generating
companies and distributed it through a single, centrally-controlled
national network. The pylons that supported the new grid's overhead cables
rapidly became a national icon of modernity and change.
In 1948 the electricity industry was nationalised, and the national grid
was extended to cover almost the whole country. Larger generating stations
were built, first fuelled mainly by coal, later by nuclear fission, and
most recently (especially after de-nationalisation in 1991) by gas. The
modern industry is also developing the use of `new' fuels, such as refuse,
wind, sun and sea-waves.
Following a national survey of the industry's buildings and sites, around
120 examples illustrating the history and diversity of the industry
have been identified as being of national importance. Together these
represent the industry's chronological depth, technological range and
regional diversity. All will be considered for protection.
Despite demolition of the upstanding part of Top Power House electric
generating station buried remains of the building survive well. The
associated leat survives particularly well throughout its length and
displays two phases of construction and numerous in situ components, which
together testify to the differing engineering and technological methods
utilised here for controlling the movement of water for a power source
over long distances across difficult terrain. The monument is an important
example of the early use of late 19th/early 20th century hydro-electric
power and its subsequent adaption in an industrial context.
Details
The monument includes the Top Power House electric generation station and
its associated leat, a late-19th century hydro-electric scheme for
Greenside lead mine. The power house, also known as No 1 Power Station, is
located on the valley floor of Glenridding Beck about 1km upstream from
Greenside lead mine. Water was tapped off Glenridding Beck just below
Kepple Cove Dam and channelled along the mountainside to an intake tank on
the valley side high above the power house. From here it was piped steeply
downhill into the power house where a turbine generated approximately 200
horsepower. The power house was built by Captain Borlase in 1890 and was
in use from 1891-1940. It provided power for winding, traction, air
compressors for drills and lighting at the mine.
The leat commences at NY34771640, just below the outflow from Kepple Cove
Tarn Dam. It runs along the northern slope of Catsty Cam as a channel in
places flanked by banks on either side with an overall width of up to 12m.
Eleswhere it has either a bank on the downslope side only, or no banks at
all where it is a rock-cut channel. At a rock outcrop at NY35491627 the
water was carried on a timber launder around the north side of the
outcrop, the launder has now collapsed and fragments of timber lie on the
ground at the foot of the outcrop. Where the leat crossed Red Tarn Beck
there are traces of timber supports for a launder to carry water across
the beck together with remains of a sluice gate which could have been used
either for tapping water from the beck into the leat, or for shutting off
the leat and tapping water from it into the beck. At NY35851638 there is
another rock outcrop; this one has some in situ remains of the timber
launder which carried the water around its northern side. However, this
launder must have gone out of use because water was subsequently taken via
a rock cut channel through the top of the outcrop. To the east of the
outcrop the leat survives as a rock cut channel straddled by numerous in
situ timbers which are thought to have supported a covering. At NY36041664
there are the remains of a stone-built intake tank complete with a
fragment of the 0.38m diameter metal pipe which took the water steeply
down hill to the power house. The course of the pipeline is visible as a
shallow trench descending the hill. Lower down the hill the pipe was taken
across a hollow on a series of stone piers of which 11 survive. At the
foot of the hill, immediately south of the valley track, there are the
remains of Top Power House which consists of a platform approximately 16
sq m with an outflow channel running around the south side. There are two
L-shaped concrete bases on the platform adjacent to the track.
The surface of a footpath crossing the leat 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.
It includes a 2 metre boundary around the archaeological features,
considered to be essential for the monument's support and preservation.
