Cement Kilns

West Thurrock

Tunnel Logo 11940s Tunnel Brand
Tunnel Logo 2Tunnel White Brand
Tunnel Logo 3Big T Brand used from the late 1960s

Location:

  • Grid reference: TQ57737798
  • x=557729
  • y=177981
  • 51°28'44"N; 0°16'17"E
  • Civil Parish: West Thurrock, Essex

Clinker manufacture operational: 1874-1976

Approximate total clinker production: 42 million tonnes (6th)

Raw materials:

  • Upper Chalk (Seaford Chalk Formation: 85-88 Ma) from a 1.2 km face progressively pushed eastwards from the plant, eventually reaching a distance of 1.2 km from the plant. During the 1960s, a further quarry was opened at 558000,179600 to the north of the A1306.
  • Alluvial Clay initially by barge from Canvey Island: from 1927, London Clay (London Clay Formation: 48-55 Ma) slurry from Aveley at 555700,180400: washmill at 555610,180110.

Ownership:

  • 1874-1968 Tunnel Portland Cement Company Ltd
  • 1968-1976 Tunnel Cement Ltd

Despite the supreme importance of this site, I have had great difficulty in getting reliable data, and history of the kilns in particular is still work-in-progress. Until I obtained aerial photographs, information on the kilns was almost non-existent, and what little I know is based largely on them. Please contact me with any relevant information and corrections.

Alternatively called Tunnel Works, this was the parent plant of the Tunnel company, and was named after Tunnel Farm, on the lands of which it was situated, and which had been so named since the mid 18th century at least. The plant started with six wet process bottle kilns, increasing to twelve (330 t/week) by 1885, at which time a set of six chamber kilns were built (150 t/week). A further set of eight (250 t/week) were built in the mid 1890s, and the bottle kilns were abandoned, leaving the output at 400 t/week, which it remained in 1907. In 1911, sale of the company to F. L. Smidth was completed. This marked the start of the FLS involvement in British and Irish production with holdings ultimately in Tunnel, Ketton, Ribblesdale and Cement Limited (Irish Cement). The immediate investment was rapid and transformed West Thurrock from an insignificant site into the largest British plant within a few decades. Blount (pp 91-95) gives an account of the plant as reconstructed. Read this account.

The old plant was completely cleared, and rotary kilns were installed. These were not FLS’s largest: larger kilns had been supplied as Wouldham A9 and Penarth B1. The plant then grew organically over the next fifty years, with nine distinct stages of up-rating – more than any other site. The result, by the end of the process, was a decidedly chaotic plant layout. As an FLS showcase, a number of pioneering plant designs were incorporated.

A3 was the first “Unax” kiln with planetary coolers (read the Engineer article describing this), while A4 was the first to be fitted with a modern chain system – an innovation that was rapidly emulated by the other companies after intelligence regarding the technique leaked out. The installation of A6 in 1934 transformed the status of the plant: it was easily the largest kiln in the country and remained so until 1961 (when it was overtaken by B1 and then by Westbury A1). From 1934 until Pitstone took over in 1957, white cement was made. An asbestos-cement plant, owned by Tunnel Asbestos Cement Co. Ltd, was established in 1936, in the quarry to the north of the kilns.

The plant was substantially damaged during WWII, and seems to be unique among UK plants in having been specifically targeted for bombing - at other places damage was random and accidental. In the post-war period, up-rating consisted of installation of kiln A8, and replacement of the old, small kilns 1-3 and the now unreliable kiln 6. B1 from 1962 became Britain’s largest kiln, until exceeded in size by Westbury A1 later that year. In overall capacity, the plant became the largest in the UK (overtaking Johnsons) with the installation of kiln 6 in 1934. It remained the largest plant until 1971, when it was overtaken by Northfleet.

The plant had run on oil from 1958, and the newer kilns had been installed without coal firing facilities. With the post-1973 rise in energy prices and market downturn, the future of the site was re-assessed. The plant had easily the highest manufacturing costs in the group, and at the increased capacity, chalk reserves were rapidly disappearing. The Essex bank outcrop is narrow, and the northward growth of Grays had cut off the quarry’s eastward development. Downward extension was limited by the water table and salt ingress. With the installation of more efficient kilns at Padeswood, Pitstone, Ketton and Ribblesdale, the brave decision was made to close the site altogether.

The site had a rail link from the outset although it always used a barge wharf to which it was joined by a 2 km standard gauge railway. A separate deep-water jetty was installed 300 m upstream in the 1930s. In line with early FLS philosophy, materials were moved around by rail rather than conveyors, and with its development in 1920-1940 it became a maze of rail track, boasting at its peak 20 km of private track. The jetty remained in use for receipt of fuel. The site was rapidly redeveloped and is now covered with light industry and warehousing. The jetty is used by an oil and chemicals transporting operation. The main chalk quarry is now the Lakeside Retail Park.

Rawmills

Washmills were always used. With the installation of rotary kilns, washmills, in closed circuit with centrifugal screeners, were installed immediately to the west of the kiln house. The screened slurry was further ground in a tube mill. These were extended in a row parallel to the kilns until the installation of Kiln 7, when there was no further room. A completely new washmill installation was then constructed in the quarry to the northeast of the kilns, and was extended as necessary with the post-war capacity increases.

Twelve distinct rotary kilns were installed in nine stages.

Kiln A1

Supplier: FLS
Operated: 12/1912 -1947
Process: Wet
Location: Hot end 557686,177923: Cold end 557689,177985: entirely enclosed.
Dimensions: metric 62.10 × 2.700B / 2.400CD
Rotation (viewed from firing end): anti-clockwise.
Slope: ?
Speed: ?
Drive: ?
Kiln profile: 0×2400: 3000×2400: 3000×2700: 10500×2700: 12000×2400: 62100×2400: tyres at 1500, 13500, 25200, 39600, 56400: turning gear at 22800.
Cooler: Concentric rotary metric 9.50 × 1.050 / 1.650 below kiln
Cooler profile: 0×1200: 3640×1200: 3640×1050: 3920×1050: 3920×1650: 9500×1650: Tyre at 2150 with trunnion end bearing: Turning gear at tail end.
Fuel: Coal
Exhaust: via dry drop-out chamber direct to stack.
Typical Output: 1912-1930 150 t/d: 1930-1948 200 t/d
Typical Heat Consumption: 1912-1930 7.89 MJ/kg: 1930-1948 7.49 MJ/kg


Kiln A2

Operated: 12/1914 -1947
Location: Hot end 557694,177923: Cold end 557697,177985: entirely enclosed.
Identical in all other respects to A1.


Kiln A3

Supplier: FLS
Operated: 4/1923 -1951?
Process: Wet
Location: Hot end 557704,177914: Cold end 557707,177977: entirely enclosed.
Dimensions: Metric (from cooler ports) 63.00 × 2.700B / 2.400CD
Rotation (viewed from firing end): ?
Slope: ?
Speed: ?
Drive: ?
Kiln profile (from cooler ports): -2000×2700: 20000×2700: 22400×2400: 63000×2400: tyres at 2200, 14100, 29100, 44100, 56100: turning gear at 26700 ?
Cooler: Unax planetary 12 × 5.40 × 0.600
Fuel: Coal: Oil on white
Exhaust: via dry drop-out chamber direct to stack.
Typical Output: 1923-1930 165 t/d: 1930-1933, 1940-1943 225 t/d: 1934-1939, 1946-1951 (white) 163 t/d
Typical Heat Consumption: 1923-1930 8.36 MJ/kg: 1930-1933, 1940-1943 7.88 MJ/kg: 1934-1939, 1946-1951 (white) 9.88 MJ/kg


Kiln A4

Supplier: FLS
Operated: 1/1929 - early 1971
Process: Wet
Location: Hot end 557715,177932: Cold end 557719,178024: hot end enclosed.
Dimensions: Metric (from cooler ports) 92.10 × 3.000B / 2.400CD
Rotation (viewed from firing end): clockwise
Slope: 1/25 (2.292°)
Speed: ?
Drive: ?
Kiln profile (from cooler ports): -2200×3000: 25000×3000: 27400×2400: 92100×2400: tyres at 2200, 13600, 29000, 46200, 65400, 89100: turning gear at 31700 ?
Cooler: Unax planetary 12 × 6.00 × 1.250
Fuel: 1929-1958 Coal: 1958-1971 Oil
Exhaust: via ID fan direct to stack. An electrostatic precipitator was added after the fan around 1950.
Typical Output: 290 t/d
Typical Heat Consumption: 7.33 MJ/kg


Kiln A5

Operated: 1931-early 1971
Location: Hot end 557723,177931: Cold end 557728,178023: hot end enclosed.
Identical in all other respects to A4


Kiln A6

Supplier: FLS
Operated: 10/1934-1960
Process: Wet
Location: Hot end 557729,177895: Cold end 557736,178045: hot end enclosed.
Dimensions: (from cooler ports) metric 150.00 × 3.750B / 3.450C / 3.900D
Rotation (viewed from firing end): clockwise.
Slope: 1/25 (2.292°)
Speed: ?
Drive: ?
Kiln profile (from cooler ports): -3500×3750: 32600×3750: 36000×3450: 105000×3450: 108500×3900: 150000×3900: tyres at 2500, 21500, 41250, 61000, 81250, 102000, 121500, 143000: turning gear at 44700 ?
Exhaust: via ID fan direct to stack. A pair of parallel electrostatic precipitators was added after the fan around 1938.
Cooler: Unax planetary 12 × 7.75 × 1.200
Fuel: 1934-1958 Coal: 1958-1960 Oil
Typical Output: 1934-1941 815 t/d: 1945-1960 790 t/d
Typical Heat Consumption: 7.05 MJ/kg


Kiln A7

Supplier: FLS
Operated: early1938 -01/04/1975
Process: Wet
Location: Hot end 557773,177928: Cold end 557778,178057: hot end enclosed.
Dimensions: Metric (from cooler ports) 129.00 × 3.600B / 3.300C / 3.600D
Rotation (viewed from firing end): ?
Slope: ?
Speed: ?
Drive: ?
Kiln profile (from cooler ports) : -3300×3600, 43000×3600, 45000×3300, 95000×3300, 97000×3600, 127700×3600, 127700×3150, 129000×3150: tyres at 4000, 17500, 36750, 57750, 79500, 100250, 122000: turning gear at 54450: dust scoops at 92500 ?
Cooler: Unax planetary 12 × 6.00 × 1.250
Exhaust: via ID fan to a pair of parallel electrostatic precipitators. A further precipitator in series seems to have been added around 1970.
Fuel: 1938-1958 Coal: 1958-1971 Oil: 1971-1975 Gas
Typical Output: 1938-1971 650 t/d: 1971-1975 620 t/d
Typical Heat Consumption: 7.10 MJ/kg


Kiln A8

Supplier: FLS
Operated: 1959q2 -01/04/1976
Process: Wet
Location: Hot end 557785,177921: Cold end 557791,178057: hot end enclosed.
Dimensions: Metric 135.60 × 3.600BC / 3.950D
Rotation (viewed from firing end): ?
Slope: ?
Speed: ?
Drive: ?
Kiln profile: 0×3600, 86000×3600, 89000×3950, 135600×3950: tyres at 10000, 31000, 53000, 77000, 101350, 125400: turning gear at 73400: dust scoops at 91000 ?
Cooler: Folax ?836 grate.
Fuel: 1959-1971 Oil: 1971-1976 Gas
Exhaust: via ID fan to a pair of parallel electrostatic precipitators.
Typical Output: 1959-1971 770 t/d: 1971-1976 730 t/d
Typical Heat Consumption: 7.01 MJ/kg


Kiln B1 (called 1a)

Supplier: FLS
Operated: 1962-01/04/1975
Process: Wet
Location: Hot end 557684,177919: Cold end 557691,178071: hot end enclosed.
Dimensions: Metric (from cooler ports) 151.75 × 3.600BC / 3.950D
Rotation (viewed from firing end): ?
Slope: ?
Speed: ?
Drive: ?
Kiln profile (from cooler ports): -3300×3600, 105000×3600, 107000×3950, 151750×3950: tyres at 4000, 37500, 75000, 112500, 140000: turning gear at 71400: dust scoops at 103000 ?
Cooler: Unax planetary 10 × 10.80 × 1.350
Fuel: 1962-1971 Oil: 1971-1975 Gas
Exhaust: via ID fan to a pair of parallel electrostatic precipitators.
Typical Output: 1962-1971 840 t/d: 1971-1975 800 t/d
Typical Heat Consumption: 6.98 MJ/kg


Kiln B2 (called 2a)

Supplier: FLS
Operated: 1949-1/1975
Process: Wet
Location: Hot end 557695,177947: Cold end 557699,178037: hot end enclosed.
Dimensions: Metric 90.00 × 3.000BC / 3.450D
Rotation (viewed from firing end): ?
Slope: ?
Speed: ?
Drive: ?
Kiln profile: 0×3000, 63000×3000, 65000×3450, 89250×3450 89250×3000: 90000×3000: tyres at 10000, 30000, 52000, 78500: turning gear at 49000: dust scoops at 55500 ?
Cooler: Folax ?624 grate.
Fuel: 1950-1958 Coal: 1958-1971 Oil: 1971-1975 Gas
Exhaust: via ID fan to an electrostatic precipitator.
Typical Output: 1950-1971 390 t/d: 1971-1975 370 t/d
Typical Heat Consumption: 7.07 MJ/kg


Kiln B3 (called 3a)

Operated: 12/1952 -1/1975
Location: Hot end 557706,177947: Cold end 557710,178037: hot end enclosed.
Identical in all other respects to B2


Kiln B6 (called 6a)

Supplier: FLS
Operated: 1961-1/4/1975
Process: Wet
Location: Hot end 557729,177894: Cold end 557736,178045: hot end enclosed.
Dimensions: Metric (from cooler ports) 151.25 × 3.600B / 3.450CD
Rotation (viewed from firing end): clockwise.
Slope: 1/25 (2.292°)
Speed: ?
Drive: ?
Kiln profile (from cooler ports): -3500×3600: 32600×3600: 36000×3450: 151250×3450: Tyres at 3250, 31250, 59250, 82500, 103250, 122750, 144250: turning gear at 78500 ?
Cooler: Unax planetary 10 × 10.80 × 1.350
Fuel: 1961-1971 Oil: 1971-1975 Gas
Exhaust: via ID fan to two parallel electrostatic precipitators.
Typical Output: 1961-1971 785 t/d: 1971-1975 745 t/d
Typical Heat Consumption: 7.02 MJ/kg



Sources: Blount, pp 91-95 (Read this.): Francis, pp 205-206: Jackson, pp 266, 302: "A combined rotary cement kiln and clinker cooler", The Engineer, CXL, p 124: Tunnel Cement (brochure), Tunnel Portland Cement Co., Ltd., 1950: Victoria County History of Essex, II, p 493

Read the Engineer article describing the first Unax cooler.


© Dylan Moore 2011: last edit 18/09/15.

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Old Maps

West Thurrock 1939 Detail The map is too cluttered to allow labels: the kilns are from left to right A1 to A7, and the hot ends are to the south.
West Thurrock 1969 Detail The map is too cluttered to allow labels: the kilns are from left to right B1- B3, A4, A5, B6, A7 and A8. The hot ends are to the south.
West Thurrock Wharf
The West Thurrock and Metropolitan plants were both some way from the river, and used rail to transport product to the wharf and to bring in coal. The original (1912) wharf was the eastern one. The deep-water wharf to the west was built in 1938, after which the eastern wharf was used only for unloading coal.

Approximate capacity: tonnes per year
West Thurrock Capacity

West Thurrock 1938 Picture
The original kilns 1 (left) and 2 around 1914.

West Thurrock 1938 Picture
Picture: ©English Heritage - NMR Aerofilms Collection. Catalogue number 57044. A high-definition version can be obtained from English Heritage. This was taken on 12/5/1938, viewed from the southwest, and shows the plant in its final pre-war form. With the light-up of kiln 7 (right), which may have taken place on this day, the plant capacity reached 900,000 tonnes per year, and West Thurrock was easily Britain's largest plant. To the left of kiln 7 is the coal store. Each kiln has its own stack, and the tallest is that of the 150 m long kiln 6, which remained for two decades Britain's largest kiln. Kiln 5 is visible beside it. Kilns 1 to 3 are enclosed in buildings - both 1 and 3 are operating. To the left of the kilns are the washmills, with trains of chalk lined up. A conveyor crosses the rail track carrying clinker to the open-air clinker store. The old finish mills are in the bottom left corner, at the south end of the clinker store. Further mills were successively added on the west side of the store (beyond the left edge). In front of the kiln complex is the now-redundant power house. In the top-left corner is the recently-constructed asbestos-cement plant. The quarry extends away by a mile from the top edge.

West Thurrock 1968 Picture
Picture: ©English Heritage - NMR Aerofilms Collection. Catalogue number A178024. A high-definition version can be obtained from English Heritage. This was taken on 12/3/1968, with north to the right, and shows the plant in its most developed form, with eight kilns, of which four are replacements of earlier kilns. From the top, the kilns are B1, B2, B3, A4, A5, B6, A7 and A8. With this arrangement the plant had a nominal capacity of 1.5 million tonnes, although only 90% of this was ever achieved. By this stage, all the kilns had acquired dust precipitators.

West Thurrock Kiln B1
Back end of Kiln B1, showing details also visible in the upper part of the aerial view above. This exemplifies the difficulty of fitting newer, larger plant into an existing layout. Centre view are two slurry blending tanks, and a slurry mixer to the right, fed by the old washmills off the right hand edge. The kiln feeder house and fan house are built over the rail track bringing chalk from the quarry to the old washmills.