The Thames Portland Cement Company (set up by Broads, London builders’ merchants) started constructing cement works to the south of the Quarry in 1910, with production commencing in 1912-3 with one rotary kiln, and a tramway to a jetty adjacent to Cliffe fort. A second rotary kiln was added in 1926. The works became the Alpha Cement Works in 1934, with a third kiln added in 1936 and a fourth in 1938. Becoming part of APCM 1938, the Alpha works remained in production until closure in 1970. It was a small works with two main blocks lying parallel and three wash mills at the northern end (Eve 2000). However, Fire Brigade inspection reports from 1956 give an indication of the complexity of such industrial sites, listing 40 separate categories of building, including laboratories, repair and engine sheds, assorted mill and pump houses, staff facilities, kilns and workshops.
APCM began mud digging in what became the lagoons in c.1934, using pontoons equipped with electric grabs and wash mills from which clay was pumped to the jetty for loading onto clay carrying vessels9 – this excavation work immediately behind the sea-wall caused some anxiety to the Kent Rivers Catchment Board in 1946 – engineer’s notes reveal a concern that the walls would be weakened, suggesting that the excavations were very close to the embankment. Clay digging ceased c.1969. Some of the lagoons have been erroneously included on the HER as flooded fields or reservoirs. A dredging barge from the excavation phase survives as a tangled mass of iron and wood on the shore of a lagoon, and the well-preserved remains of a concrete wash mill for clay mixing survives in the northern part of the Reserve. Subsequent nonindustrial use of the lagoons has included a short-lived sailing club, traces of which survive along the shore of a lagoon.
The Alpha Works site was totally cleared c.1979 with the Marinex Gravel Company (Brett Group) moving in to utilise the jetty for landing dredged aggregates, the line of the tramway for a conveyor, and a rail link to the Hoo branch line for distribution. The Quarry has been partially occupied by an industrial estate.
by Jim Preston (with additions by Richard James), Courtesy RSPB/ASE