Cement Kilns


ketton LogoEarly Ketton Logo.


  • Grid reference: SK98450566
  • x=498453
  • y=305660
  • 52°38'23"N; 0°32'42"W
  • Civil Parish: Ketton, Rutland

Clinker manufacture operational: 1929 to date

Approximate clinker production to 2015: 56 million tonnes (3rd)

Raw materials: quarry at 497700,306400 contains the following (top to bottom):

  • Great Oolite Limestone (Blisworth Limestone Formation: 165-166 Ma): 4.0 m in places
  • Great Oolite Clay (Rutland Formation: 166-168 Ma): 12.5 m - the clay used
  • Yellow Inferior Oolite Limestone (Lincolnshire Limestone Formation - Upper and Lower Members: 168-172 Ma): 21.5 m - the main limestone used
  • Upper Lias Shale (Grantham Formation: 172-174 Ma): 3 m
  • Upper Lias Ironstone (Northampton Sand Formation: 174-176 Ma): 4.5 m


  • 1929-1986 Ketton Portland Cement Co. Ltd (owned byThomas W Ward and Co. Ltd until 1981, then by Rio Tinto Zinc [RTZ])
  • 1986-2009 Castle Cement Ltd (RTZ to 1989, Scancem to 1999, HeidelbergCement to 2009)
  • 2009 to date Hanson Cement UK (HeidelbergCement)

The quarry was a historically important source of architectural building stone, and still supplies some random blocks for dimensioned stone. The plant, when launched, used some millions of tonnes of “waste” stone side-cast during many centuries of uncallowing of the free-stone. The quarry is a sedimentary geologist's paradise - see description. Because of its use of the lithologically complex Oolite, it had within the quarry components to make a wide range of four-component mixes. Ketton was probably the first plant to claim this as a strategy from the outset and it remained well-regarded for the consistency of its product.

T W Ward, the Sheffield scrap iron company, launched the Ketton project, with Tunnel as minority shareholders and technical management supplied by F. L. Smidth. Edgar Allen, whose headquarters were close to those of Ward’s in Sheffield, were dismayed that the project was supplied entirely by FLS. The plant grew organically, one kiln at a time, in line with market demand. Although the raw material is excellent for dry process, and efficient kiln systems were available before WWII, successive wet process kilns were installed. The first kiln was fitted with a festoon chain system from the outset, although the slightly earlier West Thurrock A4 was the first to have this.

The plant ran through WWII and benefited from its front-line position, although due to lack of maintenance manpower it ended up on reduced production. The plant made sulfate resisting clinker alongside ordinary clinker from 1955? to 1987.

The move to dry process finally began in 1977 with the installation of kiln 7, and with the installation of kiln 8, the wet kilns were stopped and cleared. With the market downturn, kiln 7 was shut down “for the foreseeable future” on 29/09/2008.

Although not close to large centres of population, the plant had a connection to the LMS Leicester-Peterborough railway and the east coast line, allowing access to London and East Anglia. In the modern context, its central position is advantageous.

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

Note: technical information on currently operational plants is ✄withheld in the public version of the site at present, except where already published (see references).


  • The initial plant had a washmill for clay, the resultant clay slurry being inter-ground with limestone and sand in an FLS 485 kW ball mill.
  • Similar ball mills were added at the installation of kilns 2, 3 and 4, and a second clay washmill in 1939.
  • Further similar equipment was added with kilns 5 and 6: size ?
  • For kilns 7&8, ✄

Eight rotary kilns were installed:

Kiln A1

Supplier: FLS
Operated: Mid August 1929 -1986
Process: Wet
Location: Hot end,: Cold end,
Dimensions (from cooler ports): Metric 78.00 × 2.850B / 2.250CD
Rotation (viewed from firing end): clockwise.
Slope: 1/25 (2.292°)
Speed: ?
Drive: ?
Kiln profile (from cooler ports): -2200×2850: 25000×2850: 27400×2250: 78000×2250: tyres at 2200, 13600, 29000, 48100, 69700: turning gear at 31700
Cooler: Unax planetary 12 × 4.25 × 0.880
Fuel: Coal
Coal mill: indirect fired: FLS Tirax ball mill
Exhaust: initially via ID fan direct to stack.
Typical Output: 1929-1965 218 t/d: 1965-1977 205 t/d: 1977-1986 189 t/d
Typical Heat Consumption: 1929-1946 8.30 MJ/kg: 1946-1956 7.48 MJ/kg: 1956-1965 7.89 MJ/kg: 1965-1977 8.38 MJ/kg: 1977-1986 7.71 MJ/kg

Kiln A2

Operated: 20/10/1933-1986
Location: Hot end,: Cold end,
Typical Output: 1933-1949 218 t/d: 1949-1959 223 t/d: 1959-1966 227 t/d: 1966-1979 217 t/d: 1981-1986 190 t/d
Typical Heat Consumption: 1933-1949 8.14 MJ/kg: 1949-1959 7.44 MJ/kg: 1959-1966 7.85 MJ/kg: 1966-1979 8.10 MJ/kg: 1981-1986 7.61 MJ/kg
Identical in all other respects to A1.

Kiln A3

Operated: 03/1939-1986
Location: Hot end,: Cold end,
Typical Output: 1939-1948 217 t/d: 1948-1958 223 t/d: 1958-1965 227 t/d: 1965-1978 220 t/d: 1978-1986 200 t/d
Typical Heat Consumption: 1939-1948 8.06 MJ/kg: 1948-1958 7.34 MJ/kg: 1958-1965 7.73 MJ/kg: 1965-1978 8.05 MJ/kg: 1978-1986 7.47 MJ/kg
Identical in all other respects to A1.

Kiln A4

Operated: 23/06/1954-1986
Location: Hot end,: Cold end,
Typical Output: 1954-1978 223 t/d: 1978-1986 199 t/d
Typical Heat Consumption: 1954-1964 7.51 MJ/kg: 1964-1974 8.15 MJ/kg: 1974-1986 7.55 MJ/kg
Identical in all other respects to A1.

Kiln A5

Supplier: FLS
Operated: 30/5/1962-1987
Process: Wet
Location: Hot end,: Cold end,
Dimensions (from cooler ports): Metric 145.00 × 3.600B / 3.300C / 3.600D
Rotation (viewed from firing end): clockwise.
Slope: ?
Speed: ?
Drive: ?
Kiln profile (from cooler ports): ✄
Cooler: Unax planetary 10 × 11.50 × 1.400
Fuel: Coal
Coal mill: indirect fired: FLS Tirax ball mill.
Exhaust: via electrostatic precipitator to ID fan and stack.
Typical Output: 1962-1977 594 t/d: 1977-1987 571 t/d
Typical Heat Consumption: 1962-1977 6.84 MJ/kg: 1977-1987 6.90 MJ/kg

Kiln A6

Operated: 2/1967-1987
Location: Hot end,: Cold end,
Identical in all other respects to A5.

Kiln A7

Supplier: FLS
Operated: late 1977 to 29/09/2008
Process: suspension preheater: details✄
Location: hot end (cooler ports) 498490,305665: cold end 498434,305697: unenclosed
Dimensions (from cooler ports): Metric 58.00 × 4.150(1)
Rotation (viewed from firing end): clockwise
Slope: ?
Speed: ?
Drive: ?
Kiln profile: ✄
Cooler: planetary: details✄
Fuel: ✄
Coal mill: direct? Babcock ring-ball? details ✄
Exhaust: ✄
Typical Output: ✄
Typical Heat Consumption: ✄

Kiln A8

Supplier: Polysius
Operated: 1986 to date
Process: air-separate precalciner: details✄
Location: hot end 498425,305808: cold end 498360,305788: unenclosed
Dimensions: Metric 68.00 × 4.200(1)
Rotation (viewed from firing end): anticlockwise
Slope: ?
Speed: ?
Drive: ?
Kiln profile: ✄
Cooler: grate: details✄
Fuel: ✄
Coal mill: indirect fired: Polysius roller mill - details ✄
Exhaust: ✄
Typical Output: ✄
Typical Heat Consumption: ✄


  • (1) Jackson p 284

Sources: Cook, pp 73, 115: Jackson, pp 234, 284: Pugh, p 109: “The Ketton portland cement works”, The Engineer, CXLVIII, December 13, 1929, pp 640-643: “New Cement Works at Ketton”, Cement and Cement Manufacture, 3, July 1930, pp 954-960: “New dry process unit at Ketton Cement”, Cement Technology, 7, 1976, pp 178-181: Peter del Strother, 75 years of Ketton Cement, Castle Cement Ltd, 2003, ISBN 0-9545416-0-x: much of the papers of the pre-RTZ company are now archived at Leicestershire, Leicester & Rutland Record Office. There is a video clip of the plant in the mid-1950s at East Anglian Film Archive.

© Dylan Moore 2011: commenced 07/08/2011: last edit 14/12/2016.

Return to plant list

Old Maps

Detail plans of the plant are largely complete, but further progress is prevented by lack of information on the layout of kilns 5 & 6.

Approximate capacity: tonnes per year: ✄

Picture: ©English Heritage - NMR Aerofilms Collection. Britain from Above reference number EPW028846.
Britain from Above features some of the oldest and most valuable images of the Aerofilms Collection, a unique and important archive of aerial photographs. You can download images, share memories, and add information. By the end of the project in 2014, 95,000 images taken between 1919 and 1953 will be available online.
This was taken on 30/8/1929 - around the time the kiln lit up - and shows the plant from the southeast. The initial rectilinear one-kiln plan largely influenced the subsequent developments. The quarry lands were in the background and the standard gauge quarry rail system runs across the top of the frame. The compact slurry preparation plant consisted of a tall wagon tippler that lifted trucks to the top of the limestone silos. The silos fed the rawmill in front of them, the motor and screener being in the taller part at the near end. Hidden behind the slurry silos is the clay washmill: the product of this was stored in two of the silos and fed to the rawmill with the limestone. The other two silos were used for blending before dropping slurry into the kiln feed mixer. The cold end of the kiln is to the left. The kiln had an ID fan but no dust filter. At the hot end, the planetary coolers discharged clinker into an underground conveyor that tunnelled under the tracks to an elevator that discharged either into a minimal-sized silo or a conical pile - already part-formed here. The silo fed the finish mill, with similar layout to the rawmill. The cement is conveyed by screws and elevator to four small and one large silo set in the middle of the packing and loading area. The nearer tracks communicate with main line rail and can be used to deliver cement, and for intake of gypsum and coal. The coal tippler, via an overhead conveyor, can feed the kiln coal mills, the power plant or a common stockpile between the two. The power plant (right frame) had a cooling tower for recirculating softened water. The usual FLS practice, implemented at the contemporary Hope, of grouping the rawmills and finish mills together to save labour, was not done here. View in High Definition.

ketton 1934 This was taken in April 1934, after the second, identical kiln had been installed. This doubling of capacity included also an extra rawmill, and extra finish mill and four 1150 tonne cement silos. Covered stores had also been added for limestone (tent-shaped structure in front of the plant), and for clinker (out of site on the other side). View in High Definition.

ketton 1946 This was taken on 5 April 1946, and shows the 3-kiln plant. With the third kiln, a concrete stack was built, eventually serving kilns 1-4. View in High Definition.

Ketton Picture
Picture: ©Dylan Moore 2008, and licensed for reuse under this Creative Commons Licence. This shows the preheater towers of kiln 7 (left) and kiln 8.

Ketton 7&8
Picture: ©Christine Johnstone 2011, and licensed for reuse under this Creative Commons Licence. See this and related images on Geograph. A closer view of 7 & 8 preheaters.