The information board is situated in front of four early 19th century Lime Kilns.
The Grade II listed kilns were built for the Leighs of Consall Hall, located next to the Caldon Canal. (
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The information board shows a photograph of the Churnet Valley Woodland and a pied flycatcher. There is also a labelled diagram that shows the Lime Kiln during firing. The board gives the following information;
'Consall Lime Kilns
In te late 18th century there were huge profits to be gained from industry here in the Churnet Valley. As a result many landowners backed the building of the canal, the local tramways and finally the railway.
With these in place, coal and ironstone mining and lime production could all be developed and by the mid 19th century thousands of men were employed in this valley.
The Consall Lime Kilns were likely built between 1806 and 1816 for the Leigh family, of Consall Hall. These Kilns operated as draw kilns, limestone was loaded with layers of coke from above and a fire was lit below. As it burnt through, quicklime was produced and extracted from the bottom of the kiln, further layers of limestone and coke were added to the top. In the kiln in front of you , you can still see where the quicklime would have been extracted.
Quicklime was a dangerous substance, as when cooled it will spontaneously react with Carbon Dioxide from the air and therefore before it was used, it had to be mixed with water to produce slaked lime. Slaked lime was then used to make mortar and plaster for the building trade, and by farmers to make soil less acidic.
In 1819 John Leigh's company was advertising "lime of a very superior quality from Caldon Lowe Limestone which was delivered from covered boats in any place along the line of canals." However the company overstretched itself and in 1840 Leigh went bankrupt, and the lime kilns went out of use in 1848.
Today the industry has gone leaving the valley quiet, now the home to a handful of houses and a fantastic wooded nature reserve owned and managed by the RSPB. The reserve is the home to special woodland bird species such as the pied flycatcher, redstart and lesser spotted woodpecker. Consall Lime Kilns are now designated as a Scheduled Ancient Monument and are owned by the RSPB.
Acknowledgements
The lime kilns were extensively restored in 2002. The restoration was co-ordinated by the Leek and Moorland historic building trust and funded by Staffordshire Moorlands District Council, the Moorlands Partnership Board, the Local Heritage Initiative, Rural Single Regeneration Budget, the Countryside Agency and the Heritage Lottery Fund, with support from RSPB, Tarmac and JCB."
The description about the lime kilns given by Historic England reads as follows;
"Reasons for Designation
Limestone or chalk has been the basic ingredient for lime mortar from at least Roman times. Since the medieval period, lime has also been used as agricultural fertiliser and, since the early 19th century, widely used in a variety of other industries: as a flux in blast furnaces, in the production of gas and oil, and in the chemical, pharmaceutical and food industries. The lime industry is defined as the processes of preparing and producing lime by burning and slaking. The basic raw material for producing lime is limestone or chalk: when burnt at high temperature (roasted or calcined), these rocks release carbon dioxide, leaving `quicklime' which, by chemical reaction when mixed with water (`slaking'), can be turned into a stable powder - lime. Lime burning sites varied in scale from individual small lime kilns adjacent to a quarry, to large-scale works designed to operate commercially for an extended market and often associated with long distance water or rail transport. Lime burning as an industry displays well-developed regional characteristics, borne out by the regional styles of East Anglia, West Gloucestershire or Derbyshire. The form of kilns used for lime burning evolved throughout the history of the industry, from small intermittent clamp and flare kilns, to large continuously fired draw kilns that could satisfy increased demand from urban development, industrial growth and agricultural improvement. Small-scale rural lime production continued in the later 19th and 20th centuries, but this period of the industry is mainly characterised by large-scale production and the transfer of technologies from the cement and other industries. The demand for mortars grew steadily during the 19th and 20th centuries. The successful production of mortars made with artificial cement represented an economic challenge to lime production and gradually replaced the use of lime mortars in major construction and engineering projects. From a highly selective sample made at national level, around 200 lime industry sites have been defined as being of national importance. These have been defined to represent the industry's chronological depth, technological breadth and regional diversity.
Although the kilns at Consall have been repaired and consolidated, they retain archaeological potential which will contribute to an understanding of their use and development. The kilns survive well in an area known for its industrial past. As an element in a wider industrial landscape, which includes further kilns at Froghall, canal and rail transport systems and evidence of iron working, the kilns will contribute to an understanding of the development of the lime burning industry and its relationship to other industries. There is also good potential for public benefit as an educational and recreational resource since the kilns are adjacent to a nature reserve, with convenient car park and shop facilities which incorporates a local history museum in part dedicated to the industrial history of the area.
Details
The monument includes a repaired and consolidated bank of four large lime kilns adjacent to the Caldon Canal east of Consall in the Churnet Valley, built into the east-facing hillside of Ash Sprink. The Consall lime kilns are a Listed Building Grade II.
The kilns themselves consist of stoke holes and pots, aligned north-south, within a retaining wall built into a stone-faced bank. This type of structure is called a draw kiln and allowed high level access in order to feed the kilns, and low-level access for the extraction of the quicklime in a continuous process. The retaining wall is composed of rock faced ashlar covering a length of about 50m and standing to about 10m high, built into the sloping face of the hillside. Its width including the retaining wall is about 20m. This retaining wall braces the structure against the hillside and is included in the scheduling. On the east side of the retaining wall there are four bays, each massively buttressed by inclined sections running to the full height of the structure. There are also four round-arched stoke holes set between the buttresses, each about 2m high. They formed a short tunnel leading to a smaller arch containing two corbelled brick draw eyes. Three of the four stoke holes are blocked so that only the northern one can be entered. This, however, has padlocked iron gates in front of it to prevent access. The pots were originally brick-lined and are about 4m in diameter at the mouth, narrowing towards the base. The lining at the top of the open pot has been refaced with modern bricks; the other three pots have collapsed and have been capped.
The lime kilns at Consall were continuous draw kilns. Their operation was fairly simple; coal and limestone were loaded at the top of the kiln and the coal burnt reducing the limestone to quicklime in the central part of the kiln. The quicklime was removed through a drawhole at the base.
The Consall kilns used limestone quarried at Caldon Low, about eight miles east of Consall. These quarries date from the 18th century when demand for limestone in iron smelting became increasingly important. Originally in the early 19th century limestone quarried at Caldon Low was sent four miles (6.4km) down to Froghall Wharf by gravity tramway (the kilns at Froghall are Listed Grade II). After 1802, however, limestone was sent by canal barge to the newly constructed lime kilns at Consall. Here, as at Froghall, it was reduced to lime powder by being roasted in the kilns and slaked by water. Slaking causes a chemical reaction making the lime more maleable. In the early years the slaked lime was sent by horse-drawn wagons along the plateway, a simple railroad, to Longton. After 1850 the lime was sent by rail along the new Churnet Valley Railway. The Consall lime kilns had to be rebuilt in 1820, but continued in production until the 1890s.
Lime had many uses, including plaster and cement and as a fertiliser. Increasingly in the 19th century it was used to supply the Cheshire chemical industry, but one of its most important uses was in iron smelting, and the kilns at Consall may have been producing lime to be used as a flux in ironworks in order to remove impurities.
To the north west on high ground above the kilns is a stone-edged pond about 1m deep. Most of the masonry has collapsed from this and it has an uncertain function, probably associated with spoil tips in the area. This is not, therefore, included in the scheduling." SOURCE: (
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