Cement Kilns

Norman

Location:

  • Grid reference: TL4815257299
  • x=548152
  • y=257299
  • 52°11'39"N; 0°10'3"E
  • Civil Parish: Cherry Hinton, Cambridgeshire

Clinker manufacture operational: 1904-1913, 1919-1984

Approximate total clinker production: 6.3 million tonnes

Raw materials:

  • earlier: Chalk Marl (West Melbury Marly Chalk Formation: 97-100 Ma) from quarry at 548000,257500
  • later: Chalk Marl from quarry at 548000,257200 and Grey Chalk (Zig-zag Chalk Formation: 94-97 Ma) and Middle Chalk (Holywell Nodular Chalk Formation: 92-94 Ma) from quarry at 548400,255700

Ownership:

The plant was started by A C Davis and the Keebles as a subsidiary of the Saxon Portland Cement Co., Ltd, with a view to doubling its output. It represented an aggressive move in the industry, setting up a rotary plant large by the standards of the day, from scratch. It was among the first British plants to be built exclusively with rotary kilns.

It might actually have been the first, but to my knowledge, it started slightly later than Billingham. Beddington followed the next year.

It was certainly the first British rotary plant designed specifically to use the Dry Process – a further confident gamble. The forty or so rotary kilns installed prior to these were all wet process, although in the USA dry process was at the time prevalent. It commenced with five dry process rotary kilns. Marl was crushed by roll-crusher, then dried by a pair of rotary driers heated by kiln exhaust gases. The dried marl was ground by seven Griffin mills, then blended in an elaborate elevator-fed re-circulating mixer before storage in a silo of 700 t capacity. It soon became clear that the registered output of 1200 t/week could be obtained with only three kilns, and A1 and A2 were permanently shut down after the BPCM takeover. Compared with other dry kilns installed in the early 20th century, these seem to have been relatively successful, despite the obviously primitive blending arrangements, because of the excellent combinability of the marl.

Nonetheless, the system seems to have found little favour with BPCM, which shut the plant down, re-starting in only during the brief boom in 1919. The plant was then rebuilt as wet process. The wet kiln B1 was subsequently replaced in 1949 with C1. This was a scaled-down version of the Shoreham kilns, and was the first in Britain to be fitted from the start with a Fuller grate cooler, supplied under license by Vickers Armstrong. The now relatively small plant continued into the 1980s, buoyed up by low maintenance costs on its simple process. Some respite was obtained by using off-gas from the landfill in the old quarry as a partial fuel replacement, but falling market left it as surplus capacity, and it shut in 1984. The plant used rail for most transportation until its later years in which its reduced market area could be served by road. The plant site has been redeveloped and now is a leisure centre. The older marl pit was landfilled: the more recent ones are flooded.

Rawmills

  • On dry process, marl dried in rotary driers using kiln exhaust gas was then ground in seven Griffin pendulum mills.
  • On wet process, a washmill and screeners were placed in the quarry and pumped finished slurry to the plant. From 1964, when harder Middle Chalk was being used, the screening mills were replaced with DSM screens and a 100 kW tube mill (ex cement mill from Crown & Quarry) for re-grinding the over-size.

Seven rotary kilns were installed:

Kiln A1

Supplier: Fellner & Ziegler
Operated: 9/1904-1912
Process: Long dry
Location: hot end 548174, 257275: cold end 548158, 257283: entirely enclosed.
Dimensions: metric 18.00 × 2.250 / 1.900
Rotation (viewed from firing end): anticlockwise
Slope: 1/15 (3.823°)
Speed: ?
Drive: from a common steam driven shaft: kilns, coolers, firing fans, feed screws and clinker conveyor provided with 150 kW capacity.
Kiln profile: 0×2250: 9000×2250: 13500×1900: 18000×1900: tyres at 2330, 12830: turning gear at 4270.
Cooler: rotary metric 9.30 × 0.950) beneath firing floor
Cooler profile: 0×950: 9300×950: tyres at 2500, 7425: turning gear at 7240.
Fuel: Coal
Coal mill: indirect: Griffin pendulum mill
Typical Output: 38 t/d
Typical Heat Consumption: 10.9 MJ/kg

Kiln A2

Operated: 9/1904-1912
Location: hot end 548177, 257280: cold end 548161, 257288: entirely enclosed.
Identical in all other respects to A1.

Kiln A3

Operated: 9/1904-1914, 1919-1922
Location: hot end 548180, 257284: cold end 548163, 257293: entirely enclosed.
Typical Output: 1904-1911 38 t/d: 1911-1922 63 t/d
Typical Heat Consumption: 1904-1911 10.9 MJ/kg: 1911-1922 9.4 MJ/kg

Kiln A4

Operated: 9/1904-1914, 1919-1922
Location: hot end 548182, 257289: cold end 548166, 257298: entirely enclosed.
Identical in all other respects to A3.

Kiln A5

Operated: 9/1904-1914, 1919-1922
Location: hot end 548185, 257294: cold end 548168, 257303: entirely enclosed.
Identical in all other respects to A3.

Kiln B1

Supplier: Vickers
Operated: 1922-01/08/1949
Process: Wet
Location: hot end 548166,257283: cold end 548112,257311: hot end enclosed.
Dimensions: 198’6”× 9’10½”B / 9’0¼”C / 12’0”D (metric 60.50 × 3.010 / 2.750 / 3.658)
Rotation (viewed from firing end): anticlockwise
Slope: ?
Speed: ?
Drive: ?
Kiln profile: 0×2743: 3124×2743: 4191×3010: 15164×3010: 16231×2750: 49759×2750: 52502×3658: 59207×3658: 59995×2172: 60503×2172: tyres at 2134, 17221, 35509, 53797
Cooler: rotary 6’4” × 68’0” (metric 1.930 × 20.73) beneath kiln
Cooler profile: 0×1803: 1219×2261: 5182×2261: 16231×1930: 49756×1930: tyres at 3854, 14675
Fuel: Coal
Coal mill: ?
Typical Output: 1922-1930 196 t/d: 1930-1949 247 t/d
Typical Heat Consumption: 1922-1930 8.04 MJ/kg: 1930-1949 7.51 MJ/kg

Kiln C1

Supplier: Vickers Armstrong
Operated: 15/08/1949-1984
Process: Wet
Location: hot end 548169,257296: cold end 548088,257338: entirely enclosed.
Dimensions: 300’0”× 9’0¼”B / 7’9½”CD (metric 91.44 × 2.750 / 2.375)
Rotation (viewed from firing end): anti-clockwise.
Slope: 1/24 (2.388°)
Speed: 0.89-1.5 rpm
Drive: 75 kW
Kiln profile: 0×2369: 1829×2750: 20117×2750: 21946×2375: 90068×2375: 90526×1981: 91440×1981: tyres at 2743, 18593, 35357, 52121, 68885, 85649: turning gear at 37569
Cooler: Fuller 620S grate cooler: 10° slope.
Fuel: Coal; from 1983 up to 10% replaced by Landfill Gas.
Coal mill: direct: No18 Atritor
Typical Output: 1949-1971 298 t/d: 1971-1984 308 t/d
Typical Heat Consumption: 1949-1971 7.57 MJ/kg: 1971-1984 6.37 MJ/kg


Sources: Cook, p 42: Francis, pp 208-210, 265: Jackson, pp 242, 288: Pugh, pp 69, 71-72: The Engineer, CV, March 20, 1908, pp 294-296, 298: ibid, CVI, November 13, 1908, pp 518-519. Read the Engineer article.


© Dylan Moore 2011: last edit 16/09/2015.

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Old Maps

Norman Old Detail

Norman New Detail

Approximate capacity: tonnes per year
Norman Capacity

Norman 1908
Picture: from article in The Engineer: Kiln A1 viewed westwards from the firing floor in 1904. This shows the characteristic rollers of Fellner & Ziegler kilns, and the peculiar front-mounted turning gear. The firing pipe, as was normal on the early kilns, was introduced below and on the feed side of the kiln centre line, and was directed onto the feed bed. The front of the hood is of 9" brickwork (also characteristic of Fellner & Ziegler). The operator must have approached with some trepidation, since a blow-back was likely to blow out the whole panel.

kiln diagram
Figure 21 from Butler's 3rd Edition shows this anonymously as a "typical" dry process, but it's obviously Norman's original Fellner & Ziegler kilns.

Saxon&Norman Picture: ©English Heritage - NMR Aerofilms Collection. Britain from Above reference number EPW025477.
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 14/11/1928, from the northwest, and shows Saxon (bottom) and Norman (top). View in High Definition.

Norman 1946
Picture: Norman collection: the plant viewed from the northwest in 1946, before installation of kiln C1. The drying and blending building of the original plant is still in place, but kiln B1 had been threaded through it, occupying the place of the discarded kilns A1 and A2. This and the whole range of buildings along the road side were demolished to accommodate the new kiln C1.

Norman C1
Picture: Norman collection: Kiln C1 shortly after installation in 1949, viewed westwards from the top of the raw coal hopper. The back end of kiln B1 can be seen through the hole in the cladding to the left