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.
Despite demolition and levelling of the northern section of Low Gatebeck
gunpowder works, the southern part of the site survives well and remains one
of the better preserved 19th/early 20th century gunpowder works in northern
England. It retains many of its structural components, including four pairs of
incorporating mills, two corning mills, two engine houses, two charge houses,
a watch house, glazing house, boiler house, drying house, store house and
parts of the water management system which powered the waterwheels. Many of
these surviving buildings preserve technological information relating to their
19th and 20th century use.
Details
The monument includes the upstanding buildings, ruins, earthworks and buried
remains of the southern part of Low Gatebeck gunpowder works, located on the
east bank of Peasey Beck to the north east of Endmoor village. The gunpowders
manufactured at Low Gatebeck 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 structures and
ancillary buildings associated with aspects of this manufacturing process,
together with a weir and part of the water management system constructed to
provide water power for some of the gunpowder production processes.
Gunpowder production consists of eight principal stages: preparation and first
mixing of the main ingredients of saltpetre, sulphur and charcoal, the
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. Remains of many of these survive at Low Gatebeck, including a store
house, two corning houses, two engine houses, a stove house, a glazing house,
a boiler house, four pairs of incorporating mills, two charge houses and a
watch house.
The original licence to manufacture gunpowder at Low Gatebeck was granted to
W H Wakefield in 1850 and production began two years later when the company's
main manufactory was transferred from Old Sedgwick gunpowder works. Initially,
pressing, corning and glazing of the gunpowder was carried out under one roof
of a compartmentalized building. However, a rapid growth in export orders led
to expansion of the works and the opportunity was taken to separate the
buildings and processes during the 1860s. In 1875 a tramway connecting Low
Gatebeck with Milnthorpe railway station was laid and this superseded the
horse and carts which had previously transported gunpowder from the site.
Rationalisation of the gunpowder industry led to a merger with the Nobel
organisation shortly after the end of World War I but falling orders
led to eventual closure in 1936 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 weir was constructed across Peasey Beck upstream from the gunpowder works
and a large mill race from which smaller leats ran was cut to provide water
for waterwheels and turbines to power the machinery. Steam engines were also
used as a power source. A smaller mill race flows through the southern part of
the site. The remains of the gunpowder works are described from south to
north; the remains of a pair of incorporating mills survive at the southern
end of the site. Here the gunpowder ingredients were crushed and ground
together under heavy edge grinding runners to form mill cake. Large
waterwheels and heavy edge runners of stone or cast iron were employed,
meaning the design of an incorporating mill is instantly recognisable as two
identical rectangular structures either side of a mill race and waterwheel,
with a tail race taking the used water away. When the mills were burned at the
closure of the works, the light wooden framed huts that enclosed each mill
were burned to the ground, leaving only the thick stone built three sided
outer blast walls. The incorporating mills at Low Gatebeck were overdriven,
that is, water to drive the wheel was fed from above. However, considerable
flexibility was used as a means of powering the mills when the level of the
beck was low or during severe frost: the southernmost pair of mills were
driven by electric motor, and opposite the mill are the ruins of the engine
house.
North of this incorporating mill is a round arched tunnel-like opening
in the masonry wall within which is the charge house where gunpowder was
stored temporarily before or after incorporating. A second pair of
incorporating mills stands to the north, while opposite are the ruins of a
steam boiler house where an engine was located which provided another
alternative energy source to drive the incorporating mill wheels. Between the
second and third incorporating mills are the ruins of a watch house; this was
a personnel shelter where millmen could rest in safety during a mill run,
emerging to lift the incorporated or `ripe' charge and lay a new or `green'
charge when necessary. The third pair of incorporating mills lie immediately
to the north and between this and the fourth pair of mills is another charge
house.
Approximately 100m north of the fourth pair of incorporating mills stand
remains of the glazing house. Here, graphite was added to the gunpowder to
protect against moisture and the mixture then turned in drums. Opposite the
glazing house are the low walls of a small stove or drying house where the
gunpowder was dried by hot air. To the rear of the glazing house a stone-lined
flue runs directly up the steep valley side for 60m to a tall stone chimney,
where waste smoke and gasses were expelled. Approximately 100m north of the
glazing house stands the ruins of a large corning mill. This structure housed
corning machines which undertook the most dangerous process of all, that of
breaking up the compressed gunpowder, and the thick stone and concrete blast
walls survive to their full height. An 1898 plan of the gunpowder works depict
the engine house for the corning mill lying immediately to the south, and
buried remains of this building will survive. To the north of the corning mill
there is a brick-built store house which stands to its full height. About 30m
to the north, the base and rear wall of two buildings, identified on the late
19th century plan as a pattern store and a shoemakers shop, are located, and
approximately 90m north west of these remains, in woodland close to Peasey
Beck, stand the ruins of a second corning mill, with a tall thick blast wall
located immediately to its north. Remains of a brick-built engine house stand
on the south side of the corning mill with stone engine mounting blocks
adjacent. A leat runs southwards from the engine house to enter a mill race
just south of a weir across Peasey Beck, from where water for the mill race is
tapped. Powder was initially transported around the site by horse drawn carts,
but this method was superseded by an extensive tramway system during the
1870s, and a late 19th century map depicts the full extent of this tramway
within the works. In places the course of these tramways can still be
determined.
The gunpowder works originally extended further north into the area now
occupied by a caravan park. Various workshops, boiler houses, refineries and
further mixing and corning houses originally existed in this area along with
offices. Much of the area has been levelled and the majority of buildings
have been demolished. An office building, however, does survive at the site
entrance, along with two charcoal retorts (iron vessels in which charcoal was
produced) which survive as gateposts. These features are not included in
the scheduling.
A number of features are excluded from the scheduling; these include all
modern walls and fences, and the surfaces of all access drives and paths; the
ground beneath all these features, however, is included.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
