| Summary : 19th century Portland Cement works. This was built in 1851 by IC Johnson, and a chamber kiln, invented by Johnson in 1872, is present, but shows developmental variation. The works were closed in the 1870s, when there were nine circular kilns, the chamber kiln, and other structures. Two of the circular kilns also survive, as does the bed of the canal, and adjacent tramway, which linked the works to Cliffe Creek.The remains of a number of buildings and branching rail tracks associated with the Portland Cement Works and adjacent chalk quarry were mapped from 1947 RAF aerial photographs as part of the English Heritage: Hoo Peninsula Landscape Project. The tracks converged at the head of the former tramway (later a conveyor) which transported cement to a jetty in Cliffe Creek (NMR Monument Number : 1531742). The site of the cement works is now a petrol storage depot. |
More information : The site is divided into three parts:
1) Chamber kiln. This is 70m long by 50m wide and stands to 4m high. Built of concrete, it has at least 3 arches surviving at the SW end, which is an admission to the main structure. A further 12 arches are visible in the NW side of the kiln with a concrete flying buttress to either side, the arched opening in each buttress allowing the passage of a tramway beneath. Each arch has metal fittings above it which indicate an upward opening door and leads into a circular structure, resembling a kiln, some of which retain their firebrick lining. Ash and residue remains within. Map evidence indicates that there were originally 8 such structures on either side of the kiln, with 2 further added to the NE at a later stage.
The top of the kiln is divided by a number of low walls running along the short axis, apparently corresponding with divisions between the chambers below. At the SW end, a large fire-brick lined chamber, ca 4m in diameter, is visible, with an arched opening in the base; between 2 and 4 arched flues, connected to the chamber, run along the centre top of the kiln. At the NE end these terminate in a rectangular concrete structure, possibly the remains of a chimney.
The form of th kiln is puzzling, sharing many of the characteristics of IC Jonson's patent, but with some differences. It may be a variation of the chamber kiln designed by an engineer at the nearby Nine Elms Cement Works, and also appears to share similarities with a design patented by another cement manufacturer, JB White. The top of the kiln is covered in very dense scrub and the sides have partially collapsed in places.
2) Flare kilns to the NE of the chamber kiln. At least 2 of the 9 kilns shown on the 1980 map survive. They are circular in plan, brick-built, and one has a preserved segmented draw arch with 3 stoking arch eyes. Probable revetments for tramways are visible within the undergrowth.
3) The canal linking the works to the Cliffe Creek survives as a narrow (ca 3m wide) linear depression alongside a footpath which follows the route of the former tramway. There is little evidence of internal lining apart from a wall at the NW terminus. (1)
The remains of a number of buildings and branching rail tracks associated with the Portland Cement Works and adjacent chalk quarry described by the previous authority were mapped from 1947 and 1951 RAF aerial photographs as part of the English Heritage: Hoo Peninsula Landscape Project. The tracks converged at the head of the former tramway (later a conveyor) which transported cement to a jetty in Cliffe Creek (NMR Monument Number : 1531742). The site of the cement works is now a petrol storage depot. (2-3) |