Summary
Cement kilns, including the remains of bottle kilns, a pair of kilns with heated raised drying floors, and a chamber kiln, constructed in the late-C19 in multiple phases, part of the former West Medina Cement Mills.
Reasons for Designation
The remains of a group of cement kiln structures to the former West Medina Cement Mills, Isle of Wight, are listed at Grade II for the following principal reasons:
Architectural interest:
* the group consists of various types of kiln construction including the rare survival of a chamber kiln as well as an unusual experimental form of kiln structure attached to the remains of a bank of bottle kilns;
* the group retains a significant proportion of their original construction, as well as evidence for later adaptions;
* the group maintains legibility as an important part of cement production, including the integration of the kiln and drying-floor processes.
Historic interest:
* the late-C19 kilns demonstrate the experimental and evolutionary nature of cement production at this time, illustrating well the move towards improving the efficiency of the cement manufacturing process.
History
The West Medina Cement Mills, also known as Dodnor Cement Mill, was established by Charles Francis and Sons in around 1841 on the site of an old tide mill.
Charles Francis and John Bazley White were cement manufacturers who established Francis and White in the early C19. Their business included a cement works established at Nine Elms, Battersea, Surrey. By 1825 they had become the leading manufacturers of Roman cement, a rival product to Portland cement. The partnership of Francis and White dissolved by the mid-C19 and Charles brought his sons into the company which became known as Charles Francis and Sons.
Septaria stone, a principal component in Roman cement manufacturing, had been found to be prevalent in the Solent and Dorset area. Charles Francis and Sons established the cement works on the Isle of Wight to most efficiently exploit these resources. The Roman cement product from the West Medina Cement Mills became known as Medina cement. Two pairs of Medina cement concrete houses were constructed in East Cowes in 1852, believed to be among the first concrete houses to be successfully built in Britain. Medina cement won prizes including the bronze medal at the Great Exhibition in 1851, the gold medal at the Havre Exhibition of 1868 and the highest award at the Paris Exhibition of 1875.
Charles Francis retired in 1852 at the age of 75, and his sons Charles Larkin and Alfred took over the company using the name Francis Brothers until 1865 when they divided up the company. Charles Larkin Francis went into business with his son Henry and, trading as Charles Francis and Son, took over West Medina Cement Mills (WMCM).
In around the early 1850s Portland cement began to be produced at WMCM. Chalk was shipped by sea from mainland Britain, and clay was dredged from the River Medina and mud flats at Hamble and in the waters around Southampton. The chalk was ground in a mill, and mixed with clay in a wash mill, making a thin slurry which was directed into large reservoirs also known as slurry backs (labelled on historic maps as cement pits). Over a number of weeks, the solid matter sank to the bottom and the water was drained off. The deposits were than taken to drying flats to be dried. Once dry, the slurry was taken to kilns, where a burning process occurred for eight to ten days, in a similar process for Medina cement. The kilns were initially most likely modified versions of bottle kilns with a tapering cone chimney. The lumps of slurry were loaded into the kiln with alternative layers of coke.
The First Edition Ordnance Survey map (surveyed 1863, published 1866; 1:10560) depicts the cement works with a series of buildings and banks of kilns laid out along the west bank of the River Medina. A road ran into the centre of the site, from the west. Along the west edge of the site ran the Cowes and Newport Railway, carried over the Mill Pond reservoir, located to the south of WMCM by a viaduct. The railway line was completed in 1862; Charles Francis and Son had objected to its construction adjacent to their works. Between the railway line and the mill buildings, and to the south of the service road were a series of cement pits (slurry flats) and drying flats.
In 1871, the company, then helmed by Henry Francis, went into liquidation. Henry continued to operate the business under inspection. It was eventually purchased by Richard Plews, solicitor and John Douglas, engineer and manager of the Portsea Island Gas company, creating Charles Francis, Son and Company, with Henry kept on as director. With the change in ownership came an increase in the workforce. During the late C19, several new kilns were added across the site, most built in the style of the Johnson chamber kiln. By the early C20 a further bank of five chamber kilns had been built near the centre of the works; the new kilns were a type patented by Vitale Michele, with shorter chambers and lower roofs. In 1911 new rotary kilns were installed.
WMCM ceased cement manufacturing in 1944. Part of the site became a storage and distribution depot for the cement imported to the Island by the Blue Circle Company, the rest of the works quickly became derelict and overgrown. The Cowes to Newport railway closed in 1966. In 2005 most of the ruinous cement works structures were removed, apart from the set of kilns at the south-west corner of the site and beside the old railway line which had been converted to a cycleway and footpath. In 2014 a factory was built over a large part of the former cement works site.
The kiln complex under assessment was built in the south-west corner of WMCM. It was established and developed at some point between the 1850s and 1898. It consists of a set of bottle kilns and two large kiln structures with integrated, raised drying platforms. The kilns do not appear on either First Edition Ordnance Survey maps (surveyed 1863, published 1866; 1:10560 and surveyed unknown date, published 1880; 1:2500). However, it is suggested that at least the bottle kilns, and possibly the east-west orientated kiln and attached drying platform were constructed before the 1880s. The whole L-shaped complex is shown on the Second Edition Ordnance Survey map (surveyed 1896, published 1898; 1:2500).
The structure includes of a set of six former bottle kilns. There is no evidence that the bottle kilns were used for the manufacture of Medina cement and it is assumed that they were used for the production of Portland cement. It has been suggested the kilns may have been built to increase production after 1865, when the Francis Brothers company was subdivided. Attached to the north side of the bottle kilns is a kiln structure orientated east-west. It consists of a drying floor made up of plates of iron or stone and it has a complex network of heating vents running under the drying floor. It has been suggested that it may pre-date the patenting of the Johnson kiln in 1872 and that the east-west kiln structure may have been built at the same time as the bottle kilns as a single integrated structure from the outset; however, the exact chronology of the group has not been firmly established. Between 1968 and 1973 there was a significant increase in staff at the WMCM, and the additional staff may have been employed to construct new machinery like the east-west kiln. It has also been noted that a reference to a kiln of a very similar description has been found in Henry Reid's description of the English cement industry, published in 1869. There is a row of three curved buttresses on the west end, one with an associated plaque reading ‘CF&S 1875’, which were later modifications.
The north-south kiln structure was added later and appears to be an example of a Johnson chamber kiln. It extends south from the east end of the bottle kiln row and reused two of the former bottle kilns. Its north-south orientation differs from the other chamber kilns known to exist at this site, which were orientated east-west. It is likely that the structure’s alignment was dictated by the reuse of the bottle kilns.
Isaac Charles Johnson, who originally worked for John Bazley White before establishing his own works near Rochester, Kent, developed a new kiln with the aim of improving the manufacturing of Portland and other cement. He developed the bottle kiln by adding a long horizontal chamber supported on piers and arches, with a long flue-like cavity running under a raised platform leading to a chimney vent. The chamber floor removed the need for separate drying flats, by utilising the heat of the kiln to dry the slurry. This became known as the Johnson chamber kiln, which he patented in 1872. Chamber kilns of this type did not become commonly used until the 1880s.
A study of the slurry remains have suggested that the operation of the bottle kilns, and the two chamber-style kilns may have overlapped for a time. It appears the bottle kilns were the first to fall out of use. By 1896 the east-west kiln was no longer in use, while the north-south kiln continued in operation.
An aerial photograph from 1926 shows the kiln group in a ruinous condition and no longer in use. The images show the tops of the bottle kilns, brick kiln chimney stacks and the wash mill with associated stack; these features have subsequently been heavily truncated or are no longer extant. When the rest of the cement works were demolished in the early-C21, this set of kilns were retained. In 2005 the Museum of London Archaeology Service (MOLAS) carried out a standing building survey of the ground plan of the structures on the site which were going to be preserved in-situ; elements of the kiln construction were mis-identified. In 2018 a community archaeological excavation of the kilns provided evidence for their construction including clarifying the number of bottle kilns, and the construction of the north-south and east-west kilns. The site of the wash mill was not subject to excavation.
Details
Cement kilns, including the remains of bottle kilns, a pair of kilns with heated raised drying floors, and a chamber kiln, constructed in the late-C19 in multiple phases, part of the former West Medina Cement Mills.
MATERIALS: the kilns are constructed of various types of concrete and cement, with additional brick facing and reinforcement; the remains of the kiln pots are principally rendered bricks.
PLAN: the kiln complex is arranged in an L-shape. On the north end is a kiln structure with two parallel drying floors orientated east-west (referred to as the east-west kiln). On its south side are the remains of a row of bottle kilns. Extending from the south-east corner is a chamber kiln oriented north-south (referred to as the north-south kiln).
EXTERIOR: the ruinous remains of a set of kiln structures, partially earth-covered. The following description is based on a visual inspection and the 2018 excavation.
The east-west kiln structure measures around 44m long and 18m wide. It is constructed of a mix of concrete using broken brick fragments and small rounded beach or river shingle as aggregate, reinforced by reused rail track. Later concrete walls were added to the east, south and north external chamber walls. At the east end are two kiln pots which have been infilled by waste and are surrounded by the remains of an upper wall with arch openings. On the outer face of the east side of the structure are further arched openings which most likely relate to the unloading of the kilns. Extending to the west are a parallel pair of drying chambers, divided by a concrete wall; the north and south chambers were built in two phases. The remains of the drying floors consist of plates of iron and concrete slabs, sitting on brick and concrete walls. The drying floors have been subject to partial collapse, most extensively along the north chamber. At the west end of the north drying chamber floor there is a hole which has been interpreted as the possible remains of an additional chimney. Below the floors are the remains of brick-wall voids which appear to have been used for the movement of hot gases. The void network under the south platform is more complex than under the north; it includes upper and lower voids which may have been used to allow the hot gas to pass under the floor at least twice. The structure stands on six concrete and brick tunnels. The most easterly tunnel was used to provide access to the arched unloading openings at the base of the kiln pots. At the west end of the structure are a set of three arched buttresses which have been added at a later stage; a metal plaque reading ‘CF&S 1875’ has been found in association with one of the buttresses. A brick chimney stack at the west end has been truncated. It has been suggested that there may have been an upper drying floor with suspended plates, no longer extant. It is likely there would have also been an open-side superstructure with a roof to provide a cover over the drying floor; this is also no longer extant.
To the south are the remains of a row of bottle kilns. Originally consisting of six brick-built bottle kilns, the two most easterly kiln pots were incorporated into the north-south chamber kiln. The four westerly bottle kilns have suffered the greatest amount of fabric loss at this site, including the loss of the upper tapering chimneys. The surviving remains of the kiln pots have been infilled by waste material. At least three of the bottle kilns retain their south-facing brick-arch unloading openings, partially buried. The bottle kilns are constructed of mortared brick and concrete with rounded beach or river shingle aggregate. The remains of joist holes in the south face of the kiln bank is evidence of a former wooden loading platform. Iron rail tracks have also been uncovered at the base of the kilns, for the unloading and movements of material.
The north-south chamber kiln is approximately 26m long and 17m wide. At the north end are the remains of a pair of kiln pots, infilled by waste, formerly part of the bottle kiln bank. On the east side of this end is a concreted stairway providing access to the tops of the kiln pots. The drying floor extends to the south and is constructed of bricks and concrete slabs covered in cement. The chamber platform is divided down the middle by a low north-south wall to form two drying floors. Below is a brick void with an arched roof that runs under the drying floor. The brick chimney stack at the south end has been truncated. The chamber platform sits on three arched tunnels. The north tunnel incorporates the brick-arch unloading openings at the base of the kiln pots. The central tunnel has been blocked on the east side and may have been used for storage. It is likely there would have also been a superstructure over the drying floor; this is also no longer extant.
This list entry was subject to a Minor Amendment on 20 June 2023 to update the address
