Cement Kilns



  • Grid reference: ST06636611
  • x=306630
  • y=166110
  • 51°23'11"N; 3°20'30"W
  • Civil Parish: Porthkerry, Glamorgan

Clinker manufacture operational: 1913-1979

Approximate total clinker production: 8.2 million tonnes

Raw materials:

  • Blue Lias limestone and clay (Porthkerry Member: 190-200 Ma) from the quarry adjacent to the plant (ST)306500,165800
  • Carboniferous Limestone (mainly Cornelly Oolite Formation: 335-345 Ma) from Ruthin (SS)297400,179400 – parishes of Llanilid and St Mary Hill, Glamorgan


  • 1914-1919 Aberthaw and Rhoose Point Portland Cement and Lime Co.
  • 1919-1979 Aberthaw and Bristol Channel Cement Co. Ltd

The plant commenced as a private venture with what was at the time a fairly large rotary kiln, but was overshadowed from the outset by the larger and more advanced Aberthaw nearby. Taken over by Aberthaw in 1919, the decision to put in a second kiln of similar inefficiency to the first confirmed its role as make-up capacity for the Aberthaw plant. Through the depression years it was operated only for short periods, and it only began to run to capacity in 1936.

The raw materials are essentially identical to those of Aberthaw, and were used in a similar manner. Initially the Blue Lias alone was used, removing the clay by rumbling. As higher C3S clinker became necessary, Ruthin quarry supplied limestone (CaCO3 92-96%) from 1939 to sweeten the mix. In 1947 Aberthaw and Blue Circle purchased the quarry as a joint venture. Subsequently, rumbling was abandoned and the entire un-sorted Lias was used.

The efficiency of the plant was improved in the 1960s with the installation of the third kiln. The reduction of slurry water content using deflocculants, as practiced everywhere at the time, was uniquely successful, with slurry moisture reduced from 38% to below 25%. The plant made sulfate resisting clinker alongside ordinary clinker from 1953 to 1980. Following the energy crisis, kilns 1 and 2 were stopped, and kiln 3 ceased making clinker in 1979, but during Blue Circle ownership 1983-9 the plant was used for slag drying and grinding. The plant used rail for transport. The company started its own asbestos-cement plant in the early 1930s, immediately to the west of the plant. It sold this to Turner & Newall Ltd in 1935. This plant continued in operation until 1992. Following this, the whole site was cleared. The cement plant and quarry is now largely under housing. The coastal part of the quarry has been developed as park land.

Please contact me with any relevant information or corrections. I am particularly interested in firmer dates and statistics.


Combination ball mills were used:

  • 1913 Polysius 400 kW
  • 1923 FLS 375 kW
  • 1945 ?Vickers Armstrong 600 kW
  • 1963 FLS 1190 kW

Three rotary kilns were installed:

Kiln A1

Supplier: Polysius
Operated: 1913-1975
Process: Wet
Location: hot end 306617,166129: cold end 306553,166133: entirely enclosed.
Dimensions: metric:

  • Originally 70.00 × 2.700
  • From 1945 69.09 × 2.700BC / 3.962D

Rotation (viewed from firing end): ?
Slope: ?
Speed: ?
Drive: ?
Kiln profile (from end of cooling zone):

Cooler: there was no separate cooler.

  • originally an extended nose section cooled clinker by radiation, with the firing pipe extended 5 m into the kiln.
  • from 1945, a new front section in the form of a “van der Werp” cooler was put on.
Fuel: Coal: Gas from 1972
Coal Mill: ?
Typical Output: 1913-1945 149 t/d: 1945-1968 195 t/d: 1968-1975 165 t/d
Typical Heat Consumption: 1913-1945 8.45 MJ/kg: 1945-1968 7.45 MJ/kg: 1968-1975 8.35 MJ/kg

Kiln A2

Supplier: FLS
Operated: ?1/1923 to 1975
Process: Wet
Location: hot end 306618,166118: cold end 306554,166122: entirely enclosed.
Dimensions: metric:

  • Originally 70.10 × 3.150B / 2.700CD
  • From 1945 69.09 × 2.700BC / 3.962D

Rotation (viewed from firing end): ?
Slope: ?
Speed: ?
Drive: ?
Kiln profile (from end of cooling zone):

Cooler: as on Kiln A1
Fuel: Coal: Gas from 1972
Coal Mill: ?
Typical Output: 1923-1945 161 t/d: 1945-1968 211 t/d: 1968-1975 175 t/d
Typical Heat Consumption: 1923-1945 8.5 MJ/kg: 1945-1968 7.5 MJ/kg: 1968-1975 8.4 MJ/kg

Kiln A3

Supplier: FLS
Operated: 10/1963 to 1979
Process: Wet
Location: hot end 306749,166101: cold end 306613,166109: entirely enclosed.
Dimensions (from cooler ports): Metric 136.00 × 3.600BC / 3.950D
Rotation (viewed from firing end): anticlockwise
Slope: ?
Speed: ?
Drive: 186 kW
Kiln profile (from cooler ports): ?-14000×3600: 88500×3600: 92000×3950: 136000×3950: tyres at -13000, 3400, 31400, 62400, 96400, 124400: turning gear at 66000
Cooler: Unax planetary 10 × 11.50 × 1.400
Fuel: 1963-1972 Oil: 1972-1979 Gas
Typical Output: 1963-1975 710 t/d: 1975-1979 640 t/d
Typical Heat Consumption: 1963-1975 5.65 MJ/kg: 1975-1979 6.70 MJ/kg

Sources: Cook, p 115: Jackson, pp 251, 293: “Extension of a Cement Works in South Wales”, Cement and Lime Manufacture, 36, Sept 1963, p 93.

© Dylan Moore 2011: commenced 21/01/2017: last edit 17/07/2017.

Return to plant list

Old Maps

A detail plan of the plant has been partially completed, but further progress is prevented by lack of information on the layout of the earlier plant.

Approximate capacity: tonnes per year
Rhoose Capacity