Reasons for Designation
Salt, primarily because of its supreme importance in the preservation of
food, has been an integral part of the north European economy since
prehistory. It was initially used mainly for salting fish and has been
extracted from seawater on the English coast since at least the Bronze
Age, whilst the earliest archaeological evidence from the inland brine
sites dates to the Iron Age. In more recent times salt has been used for
snow and ice clearance on roads, for fertiliser, and also as an essential
raw material in the heavy inorganic chemical industry, particularly in the
production of chlorine, caustic soda and soda ash.
Since the 18th century the rise of England's growing inland salt industry
led to the decline of sea-salt production. The inland salt industry is
defined as the extraction and purification of salt from brine springs and
rock salt. Brines form locally, immediately above the highest remaining
rock salt bed. The most important beds occur in the Cheshire-Shropshire
Basin, and parts of Worcestershire, Staffordshire, Lancashire and
Somerset.
Initially natural brine springs and pits were exploited, but by the late
Middle Ages pumps were being inserted into brine pits to increase the
supply. Developments in pumping technology led to the introduction of
steam-powered pumps, and later to the use of diesel, compressed air and
electrically-powered pumps. The brine was stored in brine tanks or
cisterns from where it passed by gravity into evaporting pans. These pans,
initially of lead but later of rivetted iron sheets, could be housed
either indoors in a pan house or outdoors, although generally fine pans
which heated brine to a higher temperature would be housed indoors while
common pans used for producing common or fishery salt would be housed
outdoors. Once evaporated the salt would be dried in stove houses then
placed in warehouses which were attached to the pan house. Common pans
were generally longer than fine pans and consisted of a brick furnace upon
which the pan rested with flues carrying heat below the pan to a chimney.
Common or fishery salt was handled as loose or bulk salt, generally
unstoved, and tipped from salt barrows or carts into large warehouses.
Pan houses consisted of dwarf brick walls supporting a timber structure
with roofs constructed with central vents to allow steam to escape. The
attached stove houses were brick built to retain heat with the hot gasses
from the furnace beneath the pan being directed below the stove house
through flues to a chimney. Lump salt would be lofted to a room above the
stove room for storage or grinding. This upper room may also contain a
crushing mill where crushed salt would be fed by chute into bags before
being stitched and sealed. Many salt works employed blacksmiths,
pansmiths, carpenters, coopers and wheelwrights, while store rooms,
fitting and repair shops for machinery and wagons were also common
features.
Following the discovery of rock salt near Northwich in 1670 a number of
mines were sunk to approximately 45m depth into the upper bed of rock
salt, a lower bed remaining undiscovered at that time. Each mine was
served by a two-stage shaft for access, winding and ventilation. Winding
in the top shaft was done by means of a horse gin while a windlass served
the bottom shaft. The shafts would have been covered by a roofed
timberstructure to keep them dry with the gin circle or gin house close
by. Following the discovery of a lower bed of rock salt in 1779 all new
mining operations were transferred to the deeper level. Steam engines were
used for winding rock salt and pumping water out of the mines and by the
19th century were widespread. The most prominent structure at the surface
was the timber headgear positioned over the shaft. Adjacent was an engine
house within which stood the steam engine which powered the winding
operations, and an integral or adjoining boiler house. Associated surface
buildings would include stores for keeping the mined rock salt dry,
crushing mills, offices, stables, a smithy, workshops and housing. Where
feasible lower bed mines were frequently positioned next to the
pre-existing canal network to facilitate bulk transport, and from the
mid-19th century most mines were connected to the developing railway
infrastructure.
The Lion Salt Works is unique in being the last surviving inland open pan
salt works in England. It contains evidence for the full range of
processes involved in the production of salt during the greater part of
the 20th century, from mining and evaporation of the brine to drying,
storing and transportation of the refined product. Additionally the
monument contains the well-preserved buried remains of part of the 19th
century Alliance Salt Works which preceded the Lion Salt Works on this
site.
Details
The monument includes the upstanding remains of the Lion Salt Works and
the buried remains of part of the earlier Alliance Salt Works. It is
located immediately south of the point where Ollershaw Lane crosses the
Trent and Mersey Canal and includes pan houses, salt store, brine tank,
bore holes, pump house, boiler house, manager's office, smithy and other
features associated with the Lion Salt Works, together with the buried
remains of open pans and other buildings associated with the Alliance Salt
Works which lie beneath the later Lion Works. The monument is divided into
two separate areas of protection.
A salt works was erected here by John Thompson and his son, also John
Thompson, in 1856. By 1874 it was known as the Alliance Salt Works and in
1888 it was sold to the Salt Union. Following disagreements between John
Thompson and the Salt Union, John and his son Henry Ingram Thompson dug a
new brine shaft, later to form part of the Lion Works, adjacent to the
Alliance Works. The Alliance Works continued to operate until its shaft
collapsed in 1898, after which it was abandoned. During the 1990s limited
excavation located the well-preserved remains of a pan house, stove house
and flue associated with the Alliance Works. By contrast the Lion Works
expanded and by 1900 three fine pan houses used for making common salt had
been constructed, together with stove houses, a brine tank, smithy, salt
store, office, and four common or fishery pans used for making coarse
salt. In 1947 the four common pans were demolished and replaced by a new
fine pan, Pan House No.4. A new bore hole with a steam engine and boiler
replaced the earlier brine shaft. In 1958 Pan House No.5 was erected. Two
years later Pan House No.2 was refurbished by constructing a mechanically
raked pan, Pan No.1 was demolished, and a submersible electric brine pump
was installed into a new brine bore hole drilled close to the first shaft.
The Lion Salt Works closed in 1986 due to the loss of its main markets in
West Africa during the civil war in Nigeria.
There are five pan houses at the Lion Works each comprising three
elements; the pan where the brine was evaporated above a furnace and flue,
the stove or hot house containing flues and drying areas, and above it the
loft which was used as a storehouse, warehouse or packing floor. Pan
House No.1 has a curved brick wall at its south west corner reflecting the
constricted space utilised for the first salt pan situated in the coal
yard of the now demolished Red Lion Hotel. A passage still exists beneath
the stove house which gave access from the hotel to the canal. Pan House
No.2 is orientated to receive coal from the canal with loading doors on
the north side which allowed salt to be tipped directly into narrowboats.
Pan House No.3 is orientated to receive coal from a railway siding
immediately to the south. Rail lines are used to brace the walls
externally and also to hold down other rail lines which support the
warehouse floor to Stove House No.3. Pan House No.4 has a steel framework
to support its roof and makes use of the external wall of Pan House No.3
on its west side. By replacing the four fishery pans the construction of
Pan House No.4 in 1947 reflected changes in the salt market. Internally it
contains an in situ crushing mill used to break up salt blocks. Pan House
No.5 was constructed after all other open pan salt works in Britain had
been demolished. An overhead walkway allowed salt to be barrowed from
Stove House No.5 to Stove House No.2.
To the east of Pan House No.2 is the brine tank, a bore hole sunk in the
1960s, and a sealed brine shaft dating to the 1890s. The tank is
constructed of riveted iron plates, sits on a brick base, and holds 30,000
gallons (136,500 litres) of brine. Beneath the brine tank is a boiler
which replaced an original Galloway boiler. Close to the south east corner
of Pan House No.4 is the pump house, engine shed, brine bore hole, brick
chimney and steam winch. An in situ horizontal steam engine, now converted
to run from an air compressor, is located in the Pump House and is linked
to a bell crank brine pump known as a nodding donkey. Other features of
this brine pump assemblage include a hand-cranked derrick winch, a return
water pump, a heat exchange cylinder and a brick support for a water tank.
The steam winch was used to pull salt vans and coal wagons along the
railway siding because the curves of the track were too tight for engines
to reach the site. South of the pump house is the boiler house and
manager's office. Within the boiler house is an 1891 Cornish boiler made
by William Lord of Bury which provided steam to the smithy and pump house.
The manager's office is a timber-framed structure with brick nogging or
panels, and is typical of many local buildings which utilise this design
in an attempt to withstand ground subsidence which is a common feature of
the area due to collapse in the vast underground salt workings. South west
of the manager's office is the smithy, a three-bay timber structure with
slate roof with a fourth bay added to the south end for the use of a
joiner. Many original features survive including an in situ line
shaft-powered circular saw, guillotine and hearth. South of Pan House No.4
and to the west of the manager's office are two railway tracks running
south. The section south of the manager's office has now been lifted. On
the western side of Ollershaw Lane is the large timber salt store known as
the Coronation Store. It was constructed in 1901 and was originally built
with an arched roof with the floor at canal towpath level. The original
roof was replaced with a pitched roof. Subsidence has now left the floor
of the salt store below towpath level.
The process of salt making began with the brine being pumped from
underground and stored in the brine tank from where it was fed by gravity
into the evaporating pans. The pan houses are lightly constructed timber
sheds covering the iron pans. This allowed the heat and steam to escape as
the brine was heated by the fires lit in brick furnaces beneath the pans.
As the brine evaporated salt crystals formed and were moulded into blocks
then to be taken to the stove house to dry. Once dry the salt could be
`lofted' through hatches to the second floor for storage, cutting, or to
be crushed and bagged. Pan Houses Nos.3 and 4, the stove houses and store
or warehouses, the manager's office, the engine shed and pump house, and
the salt store on the west side of Ollershaw Lane are all Listed Buildings
Grade II.
A number of features are excluded from the scheduling. These are: all
fencing, fenceposts, railings, gates and gateposts, the surfaces of a road
and pavement, all signposts and telegraph poles, a railway salt wagon and
all non-in situ fixtures and fittings. The ground beneath all these
features is however, included.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
