Cement Kilns


Coltness Newmains Caledonian Brand cement logoCaledonian Brand. The Caledonian Portland Cement Co. Ltd. distributed the product of Coltness, Gartsherrie and Wishaw from 1929.


  • Grid reference: NS82475534
  • x=282470
  • y=655340
  • 55°46'37"N; 3°52'26"W
  • Civil Parish: Cambusnethan, Lanarkshire

Clinker manufacture operational: 8/1914 to ?1959

Approximate total clinker production: 1.15 million tonnes

Raw materials:

  • Carboniferous Limestone (Lower Limestone Formation: 322-331 Ma) from Oxwell Mains: 370700,676200, Dunbar, East Lothian: supplemented by stone from Llangoed, Anglesey (Cefn Mawr Limestone Formation: 326-335 Ma at 263100,381600)
  • Blastfurnace slag: 1914-1927 from the Coltness Ironworks: after 1927, bought in from surrounding plants
  • Sandstone from?

Ownership: Coltness Iron Co. Ltd

Also known as Newmains Works. The iron works had experimented with slag/lime cement from the late 19th century, and from 1907 constructed substantial plant to make activated slag by the Colloseus Process. In an article in The Engineer, CIX, January 21, 1910, pp 60-61, they were described making activated slag under licence of the patentee: the treated slag is referred to as “clinker”, and the ground product is referred to as “Portland cement”. Evidently, the news that a British Standard for Portland cement had been published, had not yet reached Scotland.

Following the failure of this, they set up to make Portland clinker in 1914 using air-cooled slag as a mix component. This involved adding a rawmill and kiln system to the already substantial grinding plant. The clinker was then inter-ground with granulated slag (up to 70%). A separately-heated rotary drier was used to dry the granulated slag, but the kiln raw materials were ground by ball mill without drying: the slag was probably usually sufficiently hot to supply enough heat for this. The plant was substantially renovated in the mid-1930s. The Coltness company operated the plant, and brick, concrete and general engineering businesses as a sideline to their main interests of steel and coal mining, and after nationalisation, a rump company continued to run these peripheral concerns. The economics of the plant depended on the ability to offer pbfc at a lower price than Portland cement from England, and this became progressively less viable through the post-WWII period. The plant shut down with the purchase by Blue Circle of the limestone mine for Dunbar, and the prospect of an efficient cement plant in Scotland. The plant had excellent rail communications and used these for raw materials and product. The buildings remained in place into the 1980s, with the concrete products plant, taken over by Costain, remaining in operation, but the whole steelworks site was cleared in 2004.

The later history of this and the other Scottish slag-based plants (Gartsherrie and Wishaw) is hard to obtain. Coltness made its last cement in late 1963, but it may be that clinker production ceased much earlier. I am keen to get hold of information on their post-war activities. Please contact me with any relevant information or corrections. I am particularly interested in firmer dates and statistics, pictures and plans.


  • before 1934: a 125 kW Pfeiffer ball mill in closed circuit with an air separator. A second identical unit was added with the installation of kiln 2.
  • after 1934: a 300 kW Vickers Armstrong combination tube mill operated in open circuit.

Two rotary kilns were installed:

Kiln A1

Supplier: Pfeiffer
Operated: 08/1914-?1926
Process: "Long" dry
Location: hot end 282444,655341: cold end 282447,655307: enclosed.
Dimensions: 35.00 × 2.450B / 1.800CD
Rotation (viewed from firing end): anticlockwise
Slope: ?°
Speed: ?
Drive: ?
Kiln profile: 0×2100: 250×2450: 10750×2450: 13750×1800: 35000×1800: tyres at 1350, 14850, 28550: turning gear at 17500.
Cooler: concentric rotary metric 9.00 × 1.425 / 1.700 beneath kiln
Cooler profile: 0×1425: 5000×1425: 5000×1700: 9000×1700: tyre at 2700 + tail end bearing
Fuel: Coal
Coal Mill: direct fired, No.12 Atritor
Typical Output: 51 t/d
Typical Heat Consumption: 10.7 MJ/kg

Kiln A2

Supplier: Pfeiffer
Operated: ?1920-?1959
Process: "Long" dry
Location: hot end (cooler ports) 282452,655345: cold end 282457,655307: entirely enclosed.
Dimensions (from cooler ports):

  • ?1920-1934: 38.40 × 2.450
  • 1934-?1959: 38.46 × 2.450

Rotation (viewed from firing end): anticlockwise
Slope: 1/35 (1.637°)
Speed: ?
Drive: ?
Kiln profile (from cooler ports):

  • ?1920-1934: -1600×2450: 38150×2450: 38150×2200: 38400×2200: Tyres at -950, 12850, 30600: turning gear at 15250.
  • 1934-?1959: -1543×2450: 38211×2450: 38211×2200: 38461×2200: Tyres at -889, 12911, 30661: turning gear at 15311.


  • ?1920-1934 Pfeiffer Reflex planetary: metric 4 × 8.00 × 0.750
  • 1934-?1959 Vickers Armstrong “Recuperator” reflex planetary 10 × 14’0”× 3’6” (metric 4.267 × 1.067)

Fuel: Coal
Coal Mill: direct fired, No.12 Atritor
Typical Output: ?1920-1934 95 t/d: 1934-?1959 102 t/d
Typical Heat Consumption: ?1920-1934 7.55 MJ/kg: 1934-?1959 7.25 MJ/kg

Sources: Jackson, pp 277, 288: The Engineer, CIX, January 21, 1910, pp 60-61: “Extension of the Cement Works of the Coltness Iron Co. Ltd”, Cement and Cement Manufacture, 8, October 1935, pp 242-253; November 1935, pp 261-268. Read the "Engineer" article.

Old Maps

Coltness cement plant layout map

Approximate capacity: tonnes per year
Coltness clinker capacity
Coltness Newmains cement plant 1 Picture 1: ©English Heritage - NMR Aerofilms Collection. Britain from Above reference number SPW035860.
This was taken from the southwest. View in High Definition.
Coltness Newmains cement plant 2 Picture 2: ©English Heritage - NMR Aerofilms Collection. Britain from Above reference number SPW035861.
This was taken from the northwest. View in High Definition.
Coltness Newmains cement plant 3 Picture 3: ©English Heritage - NMR Aerofilms Collection. Britain from Above reference number SPW035863.
This was taken from the northeast. View in High Definition.
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.

These three views were taken in 1931, at the time when the refurbishment of the plant was taking place. This involved removing some of the bottlenecks arising from the plant's hurried conversion from the Colloseus activated slag process. The original plant consisted of a slag store (the building at right angles to the others, on the left side of Picture 2) fed from the ironworks by a long ropeway. From this, slag was fed to the adjacent grinding plant. On conversion to Portland cement manufacture, this became the main clinker store, but could only be fed by trucking the clinker to the ironworks, and feeding it via the ropeway. With the refurbishment, a direct belt conveyor was installed from the kilns to the store. Also added was a conveyor from the slag drier (right of the stack in Picture 1) to the rawmill feed hoppers, ensuring a dry feed for the rawmills. A significant addition was an FK pump-based system of recirculation for the three raw meal bins (occupying the building left of the stack in Picture 1), intended to reduce the variability of the rawmix. This remained best practice for dry process raw blending until the arrival of the Airmerge process in the 1950s. Refurbishment of the kiln included replacement of the old 4-tube Pfeiffer cooler with a Vickers Armstrong Recuperator.

© Dylan Moore 2011: commenced 23/03/2011: last edit 02/03/2017.

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