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.

Metal and wire fences and gates are excluded from the scheduling, although
the ground beneath them is included.

MAP EXTRACT
The site of the monument is shown on the attached map extract.
It includes a 1 metre boundary around the archaeological features,
considered to be essential for the monument's support and preservation.

Source: Historic England

Reasons for Scheduling

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.

Source: Historic England

Sources

Other
Text from information board in museum at nature reserve,

Source: Historic England