Reasons for Designation
Gunpowder was the only explosive available for military use and for blasting
in mines and quarries until the mid-19th century. Water-powered manufacturing
mills were established in England from the mid-16th century, although powder
had been prepared by hand for at least 200 years. The industry expanded until
the late 19th century when high explosives began to replace gunpowder. Its
manufacture declined dramatically after the First World War with British
production ceasing in 1976. The technology of gunpowder manufacture became
increasingly complex through time with the gradual mechanisation of what were
essentially hand-worked operations. Waterwheels were introduced in the 16th
century, and steam engines and water turbines from the 19th century. Pressing
and corning were also introduced between the 16th and 19th centuries to
improve the powders. Pressing improved the explosive power of the mill cake
and corning broke the pressing cake into different sizes and graded it with
respect to its fineness. Additional techniques were developed throughout the
17th, 18th and 19th centuries to improve the quality and consistency of the
finished product, and this in turn resulted in a variety of types of powders;
ranging from large coarse-grained blasting powders used in mines and quarries,
to fine varieties used, for example, in sporting guns.
Gunpowder manufacturing sites are a comparatively rare class of monument with
around 60 examples known nationally. Demand for gunpowder centred on the
London area (for military supply), other ports (for trade), and the main metal
mining areas. Most gunpowder production was, therefore, in Cumbria, the south
west, and the south east around the Thames estuary. The first water-powered
mills were established in south east England from the mid-16th century
onwards, and many of the major technological improvements were pioneered in
those mills. All sites of gunpowder production which retain significant
archaeological remains and technological information and survive well will
normally be identified as nationally important.
Lowwood is the best-preserved 19th century gunpowder works in northern England
and retains most of its components including an in situ 19th century Robey
boiler used in the gunpowder drying process. Many of the buildings preserve
technological information relating to their late 18th century, 19th and/or
20th century use, while remains of two in situ water turbines occupying former
wheelpits clearly illustrate the evolution of water-powered technology.
Details
The monument includes the upstanding buildings, ruins, earthworks, and buried
remains of part of Lowwood gunpowder works, located on the east bank of the
River Leven to the north east of Low Wood village. The gunpowders manufactured
at Lowwood ranged from fine powders used for sporting and military purposes to
course powders used for mining, quarrying and other blasting activities, and
the remains include a number of ancillary buildings and structures associated
with this manufacturing process, together with an in situ Robey locomotive-
type boiler which provided heat for the gunpowder drying process, two in situ
water turbines for powering machinery, and a stone weir and extensive water
management system constructed to provide water power for some of the machinery
and gunpowder production processes.
Gunpowder production consists of eight principal stages; preparation and first
mixing of the main ingredients of saltpetre, sulphur and charcoal,
incorporating of these ingredients by mixing and grinding, pressing of the
mixed powder into a `cake' to improve its specific gravity and explosive
power, corning or breaking up and sizing of the press cake, dusting of the
sized powder to remove loose particles, glazing of the gunpowder to protect
against moisture, drying in a heated building known as a stove house or drying
house, then finally packing or moulding in barrels or cartridges. Each of
these processes took place in purpose-built structures, some of which were
located away from the main group of buildings because of the danger of
explosion, and remains of buildings within which all these activities took
place survive at Lowwood.
The original licence to manufacture gunpowder at Lowwood was granted in 1798
and production began the following year. Initial sales were mainly to Africa
as part of the slave trade, but after the abolition of slave trading by
British ships in 1807 production turned towards the manufacture of powders for
industrial and civil engineering works. In the 1850s sporting and military
powders began to be produced in addition to blasting powders but with the end
of World War I demand for military explosives fell. Rationalisation of the
gunpowder industry led to a merger with the Nobel organisation and production
at Lowwood became concentrated on the manufacture of black powder for slate
quarrying. In 1926 Lowwood became part of ICI and two years later the plant
was modernised when electric turbines replaced many of the waterwheels as the
main power source. Gunpowder production at Lowwood eventually ceased in 1935
and much of the machinery was transferred to the Ardeer works in Ayrshire.
Following Board of Trade regulations many of the buildings were subsequently
dismantled and/or burned to ensure no explosives could remain in crannies.
A stone weir was constructed across the River Leven upstream from the
gunpowder works and a large mill race from which smaller leats ran was cut to
provide water power for the early machinery. Most of the remains apart from a
boiler house lie between the Leven and the mill race. These remains are
described from south west to north east; close to the original clock tower and
offices, which are situated just outside the area of protection, are the ruins
of a preparing mill where the three main gunpowder ingredients were weighed
out and given a first mix. A short distance to the east are the ruins of the
works entrance or search house where workers would remove anything liable to
cause a spark. Once through the entrance the ruins of a pair of incorporating
mills, a leat, a tail race, and part of the waterwheel survive. Here the
gunpowder ingredients where crushed and ground together under heavy edge
grinding runners to form mill-cake. Large waterwheels and heavy runners of
stone or cast iron were employed and the design of an incorporating mill is
instantly recognisable, being two identical rectangular structures either side
of a mill race and waterwheel, with a tail race taking water back to the
river. When the mills were burned at the closure of the works, the light
wooden-framed huts that enclosed each mill were burnt to the ground, leaving
only the thick stone-built three-sided outer blast walls. Six incorporating
mills were originally erected at Lowwood but by 1860 another eight had been
added and these all operated until modernisation of the plant in 1928, after
which a number were demolished. Remains of six pairs of incorporating mills
survive close by including one which remains in its original 1799 condition
and contains much technological information including in situ waterwheel
bearings and edge runner drive shaft mountings, and another which contains an
in situ edge runner grinding stone. A short distance to the north, close to
the river, lie remains of a water-powered dusting house where, in order to
remove any loose powder, it was tumbled in cylinders, while to the east, fed
by a leat which powered a waterwheel, are remains of the joiners shop and saw
mill complex. Close by, on the east side of the mill race, are the ruins of a
fuel store adjacent to a recently restored boiler house. Within this boiler
house there is an in situ Robey locomotive-type boiler which produced steam
that was fed by pipes to two gunpowder drying houses. These drying houses are
situated on the west of the mill race a short distance to the north; one is
ruined, the other has recently been renovated. Further to the west, close by
the river, are the remains of a building which at various times functioned as
a press house, magazine and packing room, while a short distance to the north
east stand the remains of a large corning mill and its leat. This structure
housed corning machines which undertook the most dangerous process of all,
that of breaking up the compressed gunpowder, and consequently the thick
stone-built blast walls of this three-sided building survive to their full
height. The remains of another large building which at various times
functioned as a corning mill or a glaze house also lie close to the river. A
leat from the mill race provided water power to drive the machinery in this
building while a short tail race returned water to the river. Nearby are the
buried remains of an open store house while to the north east lie the remains
of a packing house. An early 20th century map depicts a magazine, packing
house, press house and corning house located on the narrow spit of land at the
northern end of the site, and buried remains of all these structures will
survive. Powder was initially transported around the site by horse drawn carts
on roads, then by horse drawn bogies running on the 3ft 6in gauge tramway
which was linked by a bridge to Haverthwaite railway station on the west of
the Leven. Cuttings and embankments for the tramway still survive in places on
site.
A number of features are excluded from the scheduling; these are all
modern walls, fences, gateposts, caravans and the bases on which they stand,
the surfaces of all paths and the surfaces of all flagged and gravelled areas,
although the ground beneath all these features is included.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
