Summary
Murgatroyd's Brine Works consists of two brine pump houses, three brine pumps, a timber pump head gantry, a brine shaft, a capped brine shaft, a header tank, two external electrical pumps, a pole-mounted power distribution transformer, part of two transfer pipes and the buried remains of the original steam-power plant.
Reasons for Designation
Murgatroyd's Brine Works are scheduled for the following principal reasons:
* Survival: the remains survive well and retain both upstanding structures and below ground archaeological deposits that together illustrate the development in the pumping and transferring of brine throughout the plant's lifetime
* Rarity: the brine pumps, shaft, pump house, gantry, header tank, electrical pumps, power distribution transformer and power house are a very rare survival of a `wild' brine pumping plant that retains most of the typical features of a late 19th/20th century installation
* Documentation: a modern archaeological building survey has been undertaken which adds to the site's history.
* Potential: this site clearly has the potential to enhance our understanding of the C19 & C20 salt extraction industry in general, and in particular how this element of the industry was developed and improved during the period of brine work's lifetime.
History
Cheshire is home to the largest area of rock salt beds in Britain. Salt production was an important industry in Roman Britain and the Roman name for Middlewich was Salinae, which is taken to mean 'the salt workings'. Salt was being produced at Middlewich at the time of the Norman Conquest and by the C13 there were approximately 100 salthouses in the town, clustered around two brine pits. The Industrial Revolution saw a huge increase in salt production and in order to control the fluctuating price of salt a cartel known as the Salt Union comprising over 90% of the UK salt industry was formed in 1888. Five months after the formation of the Salt Union George Murgatroyd, a Manchester-based engineer, bought land on the edge of Middlewich and sunk a well followed by exploratory adits. A wild brine spring was found and the Murgatroyd Mid-Cheshire Salt Works Company was formed in 1889.
At its most basic level a C19 or early C20 brine extraction plant would generally comprise a mine with shafts and/or levels, pumps for drainage and/or extracting the brine, a pump house and a power house for providing power for operating the pumps. Additional features such as pump head gantries, header tanks and electrical power transformers may also be present.
A building survey of Murgatroyd's Brine Works carried out by Oxford Archaeology North in January 2011 identified six phases of development which reflect the expansion of Murgatroyd's and the plant's evolution from steam to electric brine extraction:
1) 1890-1931: construction of the shaft, timber gantry, original pump house and power house or steam engine house.
2) 1932-1946: remodelling and expansion of the complex including construction of a new pump house to replace the earlier one and the introduction of a new pump.
3) 1947-1952: construction of a header tank and pipe for pumping brine to a new brine processing plant at Elworth 2.5 miles away together with the introduction two electric pumps located in an asbestos-roofed structure on the north-western side of the new header tank. This period also saw the erection of a pole-mounted power distribution transformer.
4) 1953-1964: insertion of a new pump to replace the original steam-powered pump and extension of the pump house at its eastern end. Demolition of the original steam power house in 1952-3.
5) 1965-1977: installation of a submersible brine pump, which also fed brine into the header tank.
6) Post-1977: the site was sold to Congleton Borough Council for redevelopment. In June 2001 the surviving brine pumps, timber pump head gantry, the brine shaft, and the building enclosing the pumps and lower part of the gantry were scheduled together with an area immediately to the south of the pump house where buried remains of the C19 power house are considered to survive.
Details
Pump House
This is a single-storey, multi-phase building enclosing brine pumps for raising the brine to the surface, inspection hatches and the lower part of the timber head gantry. It is aligned east-west, measures approximately 12m by 5m, and is built largely of brick but with timber stud framing supporting asbestos sheeting on part of the south elevation. The roof is pitched and of asbestos sheeting. The western gable is the only original gable wall and it contains the original access, now boarded, which was afforded through a double door beneath a two-rowlock segmentally-arched brick lintel. The north elevation has an original window opening, now boarded, beneath a lintel of similar design to that above the west gable door. There is a wide central doorway with asbestos cladding over an earlier timber door. The doorway retains its original lintel formed of a single I-section steel beam. Adjacent to this door a brick base for a large brine storage tank has been inserted into the fabric of the pump house. The eastern gable is entirely rebuilt in buff-coloured brickwork and contains a small brick outshut that was formerly a porch or cloakroom to the pump house. The outshut has a door in its south end and a blocked doorway in its north end. The south elevation has an off-centre door that gives access though the timber stud framing into the building. There is a boarded window in the asbestos sheeting to the right of this door and a boarded window beneath a modern concrete lintel to the left of the door.
Brine Pumps
Consisting of two deep well pumps positioned atop the brine shaft and a third submersible centrifugal pump situated within the brine shaft. The two deep well pumps are both replacement pumps and were inserted in 1932 and 1953 respectively with the western pump being the earliest. They were supplied by John Thom Ltd of Walkden, Manchester, with the earlier pump retaining the Mather and Platt Ltd maker's plate on its electric motor. Both are set upon heavy cast bearings supported on a concrete floor. The pumps have working barrels or cylinders of 0.25m diameter and a piston stroke of 0.9m and carried brine into the header tank. The working barrel is attached to 61m of 0.25m diameter bore cast iron rising main. Below the barrel is 30m of 0.15m diameter bore mild steel suction pipe or tail pipe. This long tail pipe reaches deep down into the brine and serves two purposes: it draws brine from the lowest possible level where the brine is the densest and unaffected by surface water seepage, and it also allows for considerable variation in working level. The submersible pump was manufactured by Jas Beresford, model 3KT S13-5 and was installed in 1965. It is a three-stage centrifugal pump rated at 45,500 litres per hour of brine at 40m head consuming 12.5 hp. Its integral motor is rated at 13.0 hp.
Brine Shaft
Access to the brine was obtained via a rectangular shaft about 100m deep. The upper 18m of the shaft - the well head - is approximately 2.44m square and is timber-lined with pitched pine boards. The lower portion of the shaft is 1.2m square and, being driven through solid marl and rock salt, is unlined.
Timber Pump Head Gantry
The pump head gantry was constructed in 1890 and reinforced with mild steel cross bracing in 1952. It is approximately 2m square at the base and stands astride the two deep well pumps. It rises through the roof of the pump house to a height of about 9.6m.
Header Tank
Supported on a brick base measuring about 3.8m by 2.45m. It is constructed from welded steel sheeting and is supported by three transverse I-section steel joists. A central rectangular boarded window in the east wall of the tank base originally formed a doorway affording access into the interior of the base. A metal fixed ladder gives external access onto the top of the brine tank. Access into the tank base is now from the pump house. It contains two brine pipes together with electrical components associated with the operation of the electric transfer pumps and the pumping of brine to the Elworth works.
External Electrical Pumps
These are located on stone bases on a concrete platform measuring about 4.1m by 3.8m which abuts the northern side of the brine tank base. The two 'Gwynne' electric motor pumps equipped with 'Glenfield' control valves have pipes leading into the brine tank structure and electrical ducting into both the header tank structure and the pump house. A temporary structure which formerly housed the electric pumps has recently been removed.
Power Distribution Transformer
Situated a short distance to the north-west of the pump house and consisting of two timber poles, one about 6m tall the other about 7m tall, situated about 1.3m apart and connected by two metal struts, the lower one of which supports an electrical transformer box.
Power House
A former boiler house built to power the original steam pumps. It was an irregularly-shaped building located immediately south of the pump house and measured about 16m by 10m. Although the building was demolished in 1952-3 important buried remains of the footings for the building, engine and boiler are considered likely to survive.
Extent of Scheduling
This includes the pump house together with its brine pumps, brine shaft and pump head gantry, the header tank and its brick base, the two external electric pumps and the concrete base upon which they sit, the power distribution transformer and its supporting poles, the buried remains of the power house lying immediately south of the pump house, and a short length of the buried remains of the transfer pipes used for moving brine from the header tank to the processing plant at Elworth. This area includes a 2m margin beyond the buried remains of the power house, a 2m margin beyond the west side of the pump house, a 2m margin beyond the west and north sides of the power distribution transformer and its supporting poles, and a 2m boundary beyond the west and north sides of the buried remains of the transfer pipes all of which are considered essential for the support and preservation of these features. The eastern side of the area is delineated by property boundaries.
Pump House no 5, some 40m to the south of the core pump house, is not included in the scheduling.
Exclusions
All modern buildings, modern ground surfaces and property boundaries are excluded from the scheduling, the ground beneath these features, however, is included.
