Cement Kilns

Shoreham

SPCC LogoSPCC Brand.

Location:

  • Grid reference: TQ1992108610
  • x=519921
  • y=108610
  • 50°51'52"N; 0°17'45"W
  • Civil Parish: Upper Beeding, West Sussex (the southern part of the old plant was in the parish of Old Shoreham)

Clinker manufacture operational:1883-04/1991

Approximate total clinker production: 16.6 million tonnes (26th)

Raw materials:

  • Upper Chalk (Seaford and Lewes Nodular Chalk Formation: 85-90 Ma): quarry at 520860,108820.
  • 1883-1897 Medway Alluvial Clay (by barge).
  • 1897-1900 Upper Gault Clay (Gault Formation: 100-106 Ma) from Glynde 546900,109700 (by rail).
  • 1883-1897 Lower Gault Clay (Gault Formation: 106-112 Ma) from Horton 520900,112400:
    • 1900-1950 by barge down the River Adur.
    • 1950-1981 slurried at Horton and pumped to the plant.
    • 1981-1991 by road.

Ownership:

  • 1883-1890 Shoreham Portland Cement Co. Ltd.
  • 1890-1897 H. R. Lewis & Co.
  • 1897-1911 Sussex Portland Cement Co. Ltd.
  • 1911-1991 BPCM (Blue Circle).

The Beeding Portland Cement Co. was founded by Richard Ballard in 1878, but there is no indication that cement was made (at least at this site) until 1883. Six Johnson chamber kilns were in operation by 1890: output 144 t/week. The plant was taken over by the Sussex company in 1897, and was considerably extended, with 8 Michele chamber kilns, 2 Schneider kilns to burn the excess dried slurry of the Michele kilns, and finally two rotary kilns were installed in 1899. The latter was the first example of an “off-the-peg” kiln package supplied by FLS, and was one of several that pre-empted APCM's abortive attempt to monopolize rotary kiln technology. The kilns started up in 1900, and appear to have run successfully from the outset. This state of the plant is particularly well documented because of a newspaper article published in October 1902. An account of the cosmopolitan early workforce is also given below.

The date of the rotary kiln start-up is of interest because in the article, the company (SPCC) claimed it was the first (apart from a few much earlier failed experiments) in Britain. FLS say the rotary kiln was unknown in Europe before they introduced it, and imply that the Shoreham kilns were the first to operate in Britain. However, the same claim is made for other plants (see article). The actual date of light-up is not known. The FLS date (1899) is clearly of the receipt of the order. Cook gives 1902; presumably the date of the newspaper article, although the latter implies that the kilns had been operating for some time. Francis puts it “after” the Swanscombe kilns of 1901-2. Jackson says 1902. However, Spackman gives a chemical analysis of the rotary kiln clinker dated 1901. It is fair to assume that the light-up occurred in 1900 or very early in 1901. The kilns were numbers 3 and 4 in Smidth’s order list. Numbers 1 and 2 (of almost identical design) were installed at Rørdal (Aalborg), Denmark, and lit up in 1899.

Power for these kilns was by site-generated DC electricity: another first.

The chamber kilns were as follows:

  • Nos 1-4: Johnson Kilns, operated 1883-1924, output 21 t/week each.
  • Nos 5-6: Johnson Kilns, operated 1890-1924, output 30 t/week each.
  • Nos 7-10: Michele Kilns, operated 1898-1924, output 29 t/week each.
  • Nos 11-14: Michele Kilns, operated 1899-1927, output 28 t/week each.

The Schneider kilns were at 519833,108637 and 519835,108644. They were installed in 1900. Their combined output was limited by the amount of surplus dried slurry, and was around 230 t/week when all the Michele kilns were running. Heat consumption was around 4.1 MJ/kg.

After the installation of A3 in 1911, operation of the chamber and Schneider kilns was only during periods of high demand. Plant output was 184 t/d from the rotary kilns, plus 600 t/week from the static kilns. Chamber kilns 1-10 were removed in 1924, and kilns 11-14 and the Schneider kilns were removed in 1927. Rotary kilns A1 and A2 were removed in 1930 prior to replacement of A3.

It’s not clear why A3 was replaced with the similarly-sized second-hand B1, made up from bits from the kilns at Peters and West Kent. The tyre positions were adjusted to fit on the old kiln’s piers. The rest of the plant site was cleared and a new, minimal plant arrangement was installed. The plant ran intermittently during WWII, finally re-starting in early 1946.

The plant was completely rebuilt, mainly in the chalk quarry, in 1948-1950, and C1 and C2 were the first installation of a Vickers Armstrong design subsequently much replicated elsewhere. The plant re-build was regarded as state-of-the-art at the time by Blue Circle, and a detailed description was given in an article in Engineering. Kiln B1 (renamed C3) was kept in use as top-up capacity, and was modified in 1955/6 by addition of a Berz preheater (a design originally used on lime kilns) fed with filter-cake, “nodulized” by extrusion. This had moisture content 18-20%, compared with the typical slurry moisture of 42.5%. The 1959 Engineer article describes the pressing arrangements after a few years' operation - see below. The system was technically successful (unlike the UK Davis preheater installations – see Wilmington, Bevans, Dunstable) but was separately manned, and the presses were labour intensive, so the operating cost was higher than that of the wet kilns, and it was shut down in the recession of 1967. Kilns C1 and C2 were converted for filter cake feed (with no preheater) in 1983. One 20 m3 filter press for each kiln was installed in the quarry. The system proved to be limited by high dust loss loads, and failed to make economic production rates. The plant shut in 1991. Although clay was moved by barge in the early days, rail was used for all other purposes. The plant was on the LB&SC Horsham branch. This closed for all other traffic in 1965, with the section from Shoreham to the plant kept open. However, cement was all-road by 1970, coal supply was made tributary to Northfleet in 1974, and gypsum was last delivered by rail in 1980. The tracks were removed in 1988. Much of the plant including the kilns remain, in a state of increasing dilapidation.

Rawmills

  • In the 1910 plant there were two pairs of washmills in series, each rated at 75 kW, grinding chalk and clay together. Some modifications were made in the 1930s: regrind ball mill added?
  • In the 1950 plant, clay was initially ground at the clay quarry in a 112 kW washmill, and pumped to the plant site as a 70% moisture slurry. At the plant, chalk was milled with the clay slurry in a three-stage system:
    • Two 261 kW rough washmills used alternately
    • One 261 kW secondary washmill
    • Three 75kW screening mills in parallel
  • From the 1970s, the screening mills were abandoned in favour of hydrocyclones.
  • From 1981, to reduce slurry moisture, clay was ground at the plant in one of the screening mills converted into a washmill.

Six rotary kilns were installed in three phases:

Kiln A1

Supplier: FLS
Operated: 10/1900-1912, 1919-1924
Process: Wet
Location: Hot end 519827,108575: Cold end 519845,108574: completely enclosed.
Dimensions: Metric 18.00×1.500
Rotation (viewed from firing end): anti-clockwise.
Slope: 1/16 (3.583°)
Speed: ?
Drive: 2.24 kW
Kiln profile: 0×1500: 18000×1500: tyres at 2100, 8400, 15900: turning gear at 9375
Cooler: Cooler “vault”, elevator and vertical 3 m i.d. × 4.5 m high drum cooler shared with A2: shared rotary cooler (5.8×1.35) subsequently (1907?) added after drum cooler
Fuel: Coal
Coal mill: indirect: Kominor and ball mill
Typical Output: 25 t/d
Typical Heat Consumption: 9.3 MJ/kg

Kiln A2

Operated: 10/1900-1912, 1919-1924
Location: Hot end 519807,108564: Cold end 519856,108560: completely enclosed.
In all other respects identical to A1

Kiln A3

Supplier: Krupp
Operated: 1911-1931
Process: Wet
Location: Hot end 519807,108564: Cold end 519856,108560: completely enclosed.
Dimensions: metric 48.20×2.450 Rotation (viewed from firing end): anti-clockwise
Slope: 1/16.6 (3.454°)
Speed: ?
Drive: 30 kW
Kiln profile: 0×2450: 48200×2450: tyres at 890, 16820, 32020, 46140: turning gear at 30130
Cooler: Rotary Metric 19.75×2.000 beneath kiln
Fuel: Coal
Coal mill: indirect: ball mill
Typical Output: 1911-1914 108 t/d: 1919-1931 134 t/d
Typical Heat Consumption: 1911-1914 9.5 MJ/kg: 1919-1931 8.2 MJ/kg

Kiln B1 (=C3)

Supplier: made up using the rear of Peters A2 (originally FLS) and a new burning zone.
Operated: 10/10/1933-12/01/1967
Process: 1933-1955 Wet: 1955-1967 Semi-wet: filter cake from three 4.96 m3 0.8 MPa filter presses fed via an extruder to a Berz preheater.
Location: Hot end 519807,108564: Cold end 519856,108560: completely enclosed.
Dimensions:

  • 1933-1/1955 163’0”×9’0?”B/7’10?”CD (metric 49.68×2.759/2.400)
  • 6/1956-1967 lengthened to 163’2⅞” (49.76 m)

Rotation (viewed from firing end): clockwise.
Slope: 1/16.6 (3.454°)
Speed: 0.5-1.4 rpm
Drive: 45 kW
Kiln profile: 0×2070: 1524×2070: 3721×2759: 15265×2759: 16866×2400: 49755×2400: tyres at 2038, 17913, 32868, 46825: turning gear at 30968
Cooler: Rotary 69’8?”×7’0” (metric 21.26×2.134) beneath kiln
Cooler profile : 0×2134, 21257×2134: tyres at 4578, 15618.
Fuel: Coal
Coal mill: ?
Typical Output: 1933-1943 178 t/d: 1944-1954 207 t/d: 1955-1967 235 t/d
Typical Heat Consumption: 1933-1943 7.53 MJ/kg: 1944-1954 7.96 MJ/kg: 1955-1967 4.86 MJ/kg.

Kiln C1

Supplier: Vickers Armstrong
Operated: 1/1951-2/1991
Process:

  • 1951-1983 Wet
  • 1983-1991 Semi-wet: filter cake from one 20 m3 1.5 MPa filter press fed directly to kiln

Location: Hot end 519974,108624: Cold end 520080,108629: completely enclosed.
Dimensions: 350’0”× 11’6”B/10’0¼“CD (metric 106.68×3.505/3.054)
Rotation (viewed from firing end): anti-clockwise.
Slope: 1/24 (2.388°)
Speed: 0.52-1.33 rpm: from 1983, 2 rpm max
Drive: 112 kW
Kiln profile: 0×3048: 3785×3048: 6833×3505: 26035×3505: 29083×3054: 105156×3054: 105766×2121: 106680×2121: tyres at 2743, 21184, 40691, 60198, 79705, 99212: turning gear at 43510
Cooler: Rotary 90’0”×9’0¾” (metric 27.43×2.762) beneath kiln
Cooler profile: 0×2286: 2235×2762: 27432×2762: tyres at 4877, 20574: turning gear at 18288.
Fuel: Coal
Coal mill: direct: two No18 Atritors: from late 1980s, second-hand PHI roller mill
Typical Output: 1951-1969 557 t/d: 1970-1983 490 t/d: 1983-1991 434 t/d
Typical Heat Consumption: 1951-1969 7.30 MJ/kg: 1970-1983 7.13 MJ/kg: 1983-1991 5.39 MJ/kg

Kiln C2

Operated: 2/1951 to 4/1991
Location: Hot end 519973,108635: Cold end 520080,108640: completely enclosed.
Typical Output: 1951-1969 555 t/d: 1970-1983 480 t/d: 1983-1991 448 t/d
Typical Heat Consumption: 1951-1969 7.39 MJ/kg: 1970-1983 7.12 MJ/kg: 1983-1991 5.42 MJ/kg
In all other respects identical to C1


Sources: Cook, pp 42, 53, 115: Francis, pp 175, 257: Jackson, pp 257, 297: Pugh, pp 51, 154, 269-270: “Cement Works at Shoreham, Sussex”, Engineering, July 27, 1951: "New Cement Works at Shoreham", Cement and Lime Manufacture, 24, 1951, pp 71-93: "Shoreham Cement Works", The Engineer 192, 27 July 1951, pp 122-126: "Filtering Cement Slurry", The Engineer, 208, 28 August 1959, p 155: 1902 Newspaper article


Old Maps

Shoreham Old DetailThis is a snap-shot plan of the plant in 1912.

Shoreham New DetailThis is a composite map containing details from different eras that may not have co-existed.

Approximate capacity: tonnes per year
Shoreham Capacity


Shoreham 1902
Picture courtesy of Alan Collier. Picture accompanying the 1902 newspaper article, with a view from the northeast. To the left of the road in the mouth of the quarry are (foreground) the gas producer house, with the building housing the gas engine (which drove the washmills) behind. Beyond and to the left are the washmills. These were fed by tramway with chalk from the quarry face to the left and clay brought under the road from the quay. The fourteen chamber kilns are in the centre, connected to the two tallest stacks. The Schneider kilns are to the right, located so that feed material could be brought direct from the chamber kiln drying floors. Beyond in the loop of the river are the power house (with short masonry stack) and the finish mills. To the right are the two slim stacks of the rotary kilns and in the background is the long roof of the newer set of cement stores, contributing to the total holding capacity of three months' production.


Shoreham 1923
Picture: Crown Copyright 1923: British Geological Survey Cat. No. P202388. This shows the plant viewed from the west in 1923, before the chamber kilns and Schneider kilns had been cleared. The Schneider kilns are clearly visible at the north end of the plant. The tall concrete stack installed for Kiln 3 is now present.


Shoreham Picture
Picture: ©English Heritage - NMR Aerofilms Collection. Catalogue number H1398. A high-definition version can be obtained from English Heritage. This was taken on 6/6/1934, viewed from the west, showing the plant following its 1933 renovation. Slurry was supplied by washmills across the road. Coal is fed direct from rail trucks to the coal mill. The clinker goes direct to a new 300 kW finish mill in the building to the right of the kiln house, and the cement goes to a set of eight bins in the despatch building used by the previous plant. The River Adur is in the bottom left: clay was brought down the river by barge from Horton.


Shoreham 1979
Picture: ©NERC 1979: British Geological Survey Cat. No. P212485. This is the view from the west in 1979, before the semi-wet process was installed.

(This was an article published in the Sussex Daily News on Wednesday 15th October 1902, as part of a weekly series which also included: Reason's Electrical, Brighton; Tamplin's Brewery, Brighton; the Burgess Hill Brick and Terracotta Works; Rope-making at Hailsham; Dolphin Soap Works, Kingston and Regent Ironworks, Brighton - all, incidentally, extinct in 1991.) The article was re-printed as a publicity pamphlet by SPCC around 1911. A number of footnotes mentioned changes since 1902, and these are given in italics.

SUSSEX INDUSTRIES

No.2 - CEMENT MAKING: Sussex Portland Cement Company

The manufacture of Portland cement is a process with the details of which the public generally are probably quite unfamiliar. As a rule the idea of the uninitiated is that it has some relation to chalk, and perhaps one or two other substances. That the process of manufacture is on quite an elaborate scale, requiring complicated and perfectly adjusted machinery, many processes needing the most careful supervision, a great number of delicate chemical tests, and the employment of a considerable amount of skilled labour, is occasion for surprise to the majority of people. Yet this industry is one which should be of particular interest to Sussex, for it is this county which possesses two cement works of importance, where the process of manufacture is carried on by the aid of the very latest improvements. The history of Portland cement is in itself of much interest, but it is sufficient here to say that it is made, to use general terms, by the grinding together and calcining of chalk and clay. The name "Portland" was applied to it in consequence of the resemblance which the cement bore to the limestone found near Portland in England.

FORMATION OF THE SUSSEX COMPANY

The Sussex Portland Cement Company was formed, and the construction of the Newhaven Works started in 1884 by Mr A. E. Carey, the then resident engineer of the Newhaven Harbour Works, and Mr A. J. Jack, another engineer, connected with the same works. The Newhaven works were erected at Heighton on a portion of the estate of the late Viscount Hampden, who took great personal interest in the undertaking and materially assisted by his influence and support in the early development of the Company's business. Valuable help was also rendered at the starting of the concern by the late Mr. George A. Wallis (then agent to the Duke of Devonshire), who was a director of the company up to the time of his death. These works, as originally constructed, were designed for an output of 300 tons per week. They were, however, increased from time to time, and are now turning out some 600 tons per week. At the close of 1897 the works of the old Shoreham Cement Company, situate at Beeding, were acquired, the output of these works at that time being about 100 tons per week. These works have been practically reconstructed since the Sussex Portland Cement Company took them over, and they are now capable of an output of 800 tons per week, making the total output of both works 72,800 tons per annum. The number of men employed on the two works is over 300, a large proportion of these men being housed in the Company's own cottages, erected adjacent to the works. The members of the present Board of Directors, viz:- The Hon. A. G. Brand, M.P., Mr. Edward Eagar, Mr. F. G. Courthope, Mr. A. J. Jack, and Mr. J. F. Plaister, have been associated with the management of the Company since it commenced active operations in 1886, and they are all resident in Sussex. Mr. Jack was appointed General Manager in 1887, which post he continued to hold until 1891, when he resigned and joined the Board, continuing to act as Consulting Engineer to the Company. Mr. Plaister, the present Managing Director (who had assisted in the management since the commencement of 1887), then assumed the control. A representative of the "Sussex Daily News" recently visited the Company's works both at Newhaven and Shoreham, and was shewn the processes adopted from first to last, beginning with the procuring of the raw material and ending with the despatch of the finished article.

THE NEWHAVEN WORKS

Newhaven 1902

When the works at Newhaven were started in September, 1884, the downs sloped gently to the roadway. Since that time, no fewer than eight acres of chalk soil have been cleared, and where the hill side formerly declined gradually to the valley of the Ouse, it is now perfectly level ground. On the top of the hill, a tumulus once existed, and an old Roman brooch (now in the museum at Lewes) was found near this spot. The chalk, of course, is here in abundance and the other portion of the raw material, gault clay, is obtained by the Company from a pit at Glynde, the railway affording every facility for transit. There is an extensive face of chalk at Newhaven, the hill in one place having been cut right through. No less than 98 per cent of carbonate of lime is contained in the chalk here, and this a great advantage in view of the purpose for which the chalk is required. In order that night may not interfere with the cutting away of the hill side, a travelling electric light, capable of journeying along the whole face of the cliff, is used, its rays being directed upon any spot where work is going on. The proportion of chalk to clay is, speaking roughly, three to one. The chalk is brought whence it is cut to the washmill in trucks which run along a small railway. These trucks work on a hinge, so that the load is easily tipped, and the contents emptied into the mill's mouth. A similar course is followed with the clay. Inside the mill a process, quite terrifying in appearance, goes on. The mixture is churned and ground and stirred by harrows, while a small stream of water constantly flows in. The effect of the washing is to get an intimate compound, and to reject the useless matter, such as flints, which are not required. When the washing process has been duly accomplished the stuff is passed through a fine grating which stops the flints, &c., and allows the passage only of the washed chalk and clay, which from this point is technically called slurry. The latter then goes into a "mixer", where are left behind those small flints which have not previously been eliminated. From the "mixer" the slurry is "elevated" by a series of buckets on a wheel, and every bit is ground as small as possible between mill stones. In fact one of the most important stages in the manufacture of the cement is to get this stuff ground fine enough, though up to recent years this part of the process was considerably neglected in most of the English Works. The slurry has now to pass through a 180-sieve, which is a sieve containing 32,000 meshes to the square inch; and it is important that the residue should not exceed five per cent. As a matter of fact, the Company grind their residue to three per cent. Constant tests are made in order that this fineness should be secured. By means of powerful pumps the slurry is now conveyed to the drying floors, which are fitted with flues in order that the waste heat from the kilns, which adjoin them, shall pass over and under them, drying the slurry and converting it into what is technically designated "slip". As the slip dries, it is broken up and wheeled into the kilns, where it is deposited with alternate layers of coke.

TWENTY THOUSAND TONS OF COKE

The consumption of fuel by this method is about half a ton of coke to a ton of cement, and the quantity of coke consumed per annum is 20,000 tons. The fumes and moisture from the kilns are carried off from the drying floors by means of high chimneys. When the kilns are lighted, they are sealed up in front and at the bottom, and a fresh quantity of slurry is run on to the drying floors. Thus, while the kilns are burning, they are at the same time drying other floors of slurry. There is a range of 21 kilns, and the time a kiln takes to burn through and dry a floor is four or five days. The burning process, too, is most important, for it is necessary that the contents of the kiln should be burnt thoroughly, but neither over nor under burnt. If they are over burnt they are of no value at all, while under burnt material is of inferior quality, and likely to do harm in the work for which it is used. In consequence of this the kilns require very careful attention. After the stuff is burnt, the change in its composition has a corresponding change in name, and what was slurry now becomes clinker, the effect of the burning being to drive out the carbonic acid gas and to bring about chemical combinations of the lime and clay. All partly burnt stuff has to be carefully removed, and a special staff of men is engaged for this purpose.

Pamphlet footnote: Since the above was written, a Rotary Kiln plant of the latest type has been installed at the Newhaven Works.

Trucks are run right into the mouth of the kilns, where they are filled, then they are taken by a tramway over a weighing bridge, where they are weighed and the weights registered. The clinker is then passed through two large crushers into a "hopper", which feeds the ball mills, consisting of drums half full of heavy steel balls, and the revolutions of which grind the clinker down to a certain degree of fineness. From the ball mills the stuff is passed through a sieve into a hopper, and thence into the tube mills, which finish this process by grinding the clinker into an impalpable powder. The last grinding is, of course, most essential and complete; and when the process is ended the cement will pass through a sieve, having 5776 meshes to the square inch, leaving a residue of no more than five per cent. This is the result of ordinary grinding, but the machinery now is so excellent that the cement can be ground to nearly any degree of fineness; indeed, the Company have a special specification, where it has to pass through a sieve with 32,000 meshes to the square inch, leaving a residue not exceeding ten per cent.

The pamphlet changed this to 15%! In modern cements, this quantity is essentially zero.

Formerly this grinding was done by mill stones.

A STORE FOR 8,000 TONS

After passing through the tube mills the cement is elevated into an automatic weigher; thence into a conveying screw, which takes it the whole length of the store; and it is then dropped into bins, the object of which is to aerate it thoroughly before it is despatched. Bins are kept for various customers. The whole of the cement in each of these bins is tested daily as manufactured until the bin is full; and it is again tested as it is sent out. One advantage of this store (which is lighted by electricity), is that all the work therein is done under cover; and it is so large that there is no necessity to bag the material up until it is actually wanted. This again gives the cement the additional benefit of aeration. On either side of the store are lines of rails, and the trucks run up them under cover. As each truck is filled it is covered with a sheet. After this the trucks leave the works, and their contents are not touched until they reach their destination, every precaution being taken to ensure their arrival at the consumer's in a perfectly dry state. There is space for twenty trucks on each side of the store, and their total contents when full equal 200 tons of cement. With an efficient staff of men this quantity can be loaded in an hour. The storage capacity is 8,000 tons. The bulk of the Company's trade being home trade, the principal part of the packing is done in sacks, and there is a store in which the sacks are kept, but a certain amount is done in casks, and the Company have their own cooperage, where their casks are made.

THE MACHINERY

The engine house contains two compound condensing engines, one of 400 h.p. which drives the dry mill, and a 200 h.p. engine, which drives the wet plant. Adjoining there is an electric installation for the lighting of the whole of the works, and the driving of some of the machinery. The wear and tear of the machinery in all of the departments of cement manufacture is very heavy, and it is therefore most important that it should be maintained in first-class order and every little defect immediately remedied. In order that this shall be effected without delay of the gear being sent away the Company have their own staff of fitters and a large fitting shop, containing all necessary lathes, shaping machines, etc. This machinery is driven by electricity. The fitting shop is built entirely of concrete, and adjoining is the smith's shop. Before the company did away with the mill stones in favour of new dry grinding machinery they decided to put up an additional mill, on the most modern lines. The new mill is driven by a compound condensing engine of 250 h.p. of the marine type. The mills are all on one floor, and instead of feeding into a crusher, trucks are brought direct from the kilns into the elevator and are emptied direct into the ball mill. What follows then is practically the same as before, but afterwards the cement is brought into a belt conveyor, which has the double advantage of conveying the cement with the expenditure of less horse power than that necessitated by the screw conveyor, and of being open to the atmosphere, and thus aerating the cement as it is carried along to be dropped on to the screw which delivers it into the bins. A book is kept in each mill for recording the testing of the grinding, which is done every half-hour, sieves being specially provided for the purpose. This is quite independent of the ordinary testing in the testing rooms, each man being responsible for his own department. An automatic weighing machine is also used to see that the proper quantity is being sent through the mills, and the results are duly booked, so that there is little chance of a slip.

AN ELABORATE TESTING SYSTEM

The careful testing of the finished cement and the materials in the various stages of manufacture is imperative, and for this purpose a laboratory and testing room are provided where tests of every possible description are carried on daily by an efficient staff of chemists and assistants. In the laboratory the raw materials, viz., chalk, clay, coal, coke, etc., are constantly tested, and the chemists are also occupied in research work with the view of bringing about further improvements. Nothing is passed into the kilns until it is absolutely certain that the chemical combination is correct. Besides testing the fineness of the grinding of the chalk and clay as passed through the wet mill, a process is adopted to ascertain the carbonate of lime in the slurry; this is done half-hourly or hourly as may be required by means of a chemical apparatus called a calcimeter. These Sussex Works were about the first English Works to adopt this instrument, although its use has since become almost universal in the cement trade. This, like many other scientific processes, is copied from the Germans, whose methods the Sussex Portland Cement Company have been at pains to consider and where advantageous, adopt. After the cement is ground, daily samples of the manufacture are brought into the testing room for chemical examination, and are tested for fineness, setting time, specific gravity, weight per bushel, and breaking strain, also for soundness. The tests for breaking strain are of considerable interest. The cement is mixed with a certain quantity of water and forced into moulds, where it remains for twenty-four hours until thoroughly set. The briquettes thus formed are taken out of the moulds and are placed under water, and allowed to remain there for periods extending over two, six and 27 days, three months, six months, and twelve months. At the end of each of these periods the briquettes are taken out, and broken in the testing machine. The usual requirements of engineers at the present time are a breaking strain of 400 to 450 lbs per square inch after seven days. Of the briquettes, which our representative saw tested, one gave a breaking strain of 590 lbs after seven days, and another, after three months, failed to break at 1000 lbs.

THE MAKING OF BRIQUETTES

For practical purposes, it is the finely ground cement which is of the greatest value. To prove the value of the fineness of the cement it is made up into sand briquettes, the proportion being three of sand to one of cement, and it is very important that the consumer should see that he buys a cement that will give him a good breaking strain with sand briquettes. The breaking strain of a sand briquette required by the average engineer is 200 lbs per square inch after 28 days. The sand briquettes which have remained that time and which our representative saw broken gave breaking strains of 390 lbs and 470 lbs.

These values correspond to modern EN 196 compressive strength values of 18 and 23 MPa. The engineer would apparently accept 7 MPa. The British Standard for cement had not yet been published. Modern 28-day strengths are around 60 MPa.

More importance is attached to this test than to the neat cement test, but these sand briquettes require very careful making; as the comparative results obtained would be useless unless precisely the same conditions were observed for making each briquette, this necessitates the employment of special apparatus and an expert tester. Different times of setting are, of course, required for different purposes. For instance, drainage and sea works require fairly quickly setting cement, while for general work, the time required is longer; and the company naturally make a special point of suiting the requirements of their customers, their system being so perfect that they can prepare their cement to set in any time from twenty minutes to twenty-four hours. Circular pats of cement are tested for the initial and final set by means of a pointed instrument pressed downward by a 2 lb weight, the power which the point has of penetrating the pat giving the extent to which it has set. As a test for soundness, the pat is put on a piece of glass, placed under water, and watched for any signs of cracking, or of coming away from the glass. This test is carried out in fresh water, but there are other tests by means of sea water and boiling. From first to last the results of all the tests are registered. Every process is kept recorded and has been for years past, the results forming quite a library. If a consumer wishes to know the result of the test of any particular supply it can be furnished at once, the tests being registered with the name of the consumer opposite them. A series of tested briquettes is also kept, which can be referred to if necessary, and the Company also have a sample pat of every day' s manufacture since the works were started.

THE SHOREHAM WORKS

Shoreham 1902

In the reconstruction of the Shoreham Works, which are situated at Beeding, the Company were able to allow for many improvements which it was found impossible to adopt at Newhaven, and here the processes are carried out upon what are recognised as absolutely the most modern lines. An exceptional advantage of the Shoreham works is that they are situated on the banks of the river Adur. The result of this is that the Company are able to despatch their cement and receive coal, coke, and other supplies in their own barges by water. The clay for use in the works is brought by barge from the Company's own freehold clay-pit at Horton, about three miles from the works. The unloading is effected by means of a steam crane. One of the cement stores is built on the wharf so that the cement can be loaded into the barges direct from the store. There is a considerably larger face of chalk here, but it is cut out and conveyed to the works on a tramway in exactly the same way as at Newhaven. There is a gas-making plant for driving the gas engines; and on the side of the cliff from which the chalk is being cleared a new washing plant and wet mill, which will be driven by a 250 h.p. gas engine is in course of erection. The process followed as to the chalk and clay is similar to that at Newhaven, but the washing and mixing plant is more elaborate owing to the more modern methods of burning, which require different methods of washing to achieve the same chemical result. At Shoreham there are two washmills and two mixers instead of one of each, so that if one breaks down the other is ready to go on. The new wet plant which is being put up will also be duplicated. The present plant is not sufficient to deal with the larger burning plant without working night and day, and it is the Company's intention to avoid this if possible.

THE GERMAN SCHNEIDER KILN

The drying process is practically the same as at Newhaven, but it was found that so much heat was being wasted in the kilns, that another drying floor was constructed over the top of the kilns on which stuff can be dried to feed German Schneider continuous kilns. This kiln was invented by a German, from whom it takes its name, and is not only economical in the matter of fuel consumption, but also burns more regularly and efficiently than the old type. The slip is taken off the top of the chamber kilns by tramway and fed into the Schneider with layers of coke in a similar way to that adopted in the chamber kilns; only in this instance the quantity of coke required is much less and the kiln is never stopped for drawing, for as fast as fresh stuff is put in to burn the finished material is being removed. There are altogether fourteen chamber kilns and two Schneider kilns. Each Schneider kiln turns out 100 tons of clinker per week, whereas the ordinary chamber kiln only deals with from 25 to 30 tons per week. The process at Shoreham is completely automatic from first to last, the stuff being handled as little as possible.

AN IDEA FROM AMERICA

Having found out what were the methods employed on the continent the Company turned their attention to America, where they found the rotary kiln system in vogue. By this system, which the Company adopted, it is possible to dry and burn the cement and completely manufacture it in 2½ hours, whereas by the old system it takes from ten days to a fortnight. The rotary kiln is fed with the slurry by long pipes leading from tanks, the feed being controlled by one man. The kiln itself is a long inclined cylinder lined with fire bricks, which is made to revolve slowly. The slurry is fed into one end, and as it travels to the further end it gradually dries and burns, eventually dropping out of the lower end of the tube in the form of clinker; but instead of being in large lumps it is in small lumps the size of beans. This kiln ensures perfect burning of the clinker, and there is little or no half-burnt stuff. The burning is done with finely powdered coal, which is blown into the kiln by means of a fan and ignited immediately it enters the kiln. As the clinker falls from the kiln it is taken up in an elevator and dropped into a cooler, whence it is conveyed automatically to the mill to be ground. Coal fuel, being used instead of coke, enables the manufacturer to be more independent, as the coke market is subject to more heavy fluctuations than the coal market, besides which the supply of coke locally, owing to the introduction of water gas, is not nearly so large as it was formerly.

GAS AND ELECTRIC POWER

The whole of this plant is driven by electricity, and it is so admirably arranged that it requires only two men to look after it, one man for each kiln. The Sussex works were the first in England to adopt this system and make it a practical success. Since the plant was started at the Shoreham works it has been running continuously with scarcely a hitch. To start the plant the Company had an advantage over other English cement makers in securing the services of men from Denmark, who had been working a similar plant in that country, which was then practically the only place where lengthy experience of drying and burning slurry with rotary kilns could be gained.

Pamphlet footnote: Since the above was written, a further rotary kiln plant has been installed, capable of an output of 1000 tons per week.

In the works is a 100 h.p. gas engine which drives the coal grinding drying plant for the rotary kilns, in itself quite an elaborate process. The main engine which drives both the wet and dry mills is of 400 h.p.; and the electric plant is driven by a 60 h.p. Parson's steam turbine, and two compound condensing engines. One of the cement stores is similar to that at Newhaven, and there is an additional store nearing completion. When completed the two stores will have accommodation for 9,000 tons. It is possible, in the two stores, with an efficient staff working simultaneously, to load 260 tons per hour, all the work being done under cover. A similar arrangement to that at Newhaven is effected in regard to the trucks, which are brought under cover alongside the bins. As at Newhaven a fitting shop, laboratory, testing room, and competent staff of chemists are provided. There is also a staff of draughtsmen kept, the Company designing all their own works, mills, etc. Both the Newhaven and Shoreham Works are connected by sidings with the London, Brighton and South Coast Railway, which affords every facility for the rapid dispatch of the cement by rail and also for shipment by the Railway Company's wharves at both ports.

SOME GREAT UNDERTAKINGS

The important works supplied by the Company bear ample testimony to the high quality of their cement. To the Newhaven Harbour Works over 17,000 tons were supplied during the construction of the breakwater, which is a fine example of monolithic construction and considerable additional quantities have since been supplied to the Harbour for minor works and repairs. The Company's cement has always proved eminently reliable and suitable for sea works, and has been used for large concrete groynes at Brighton and Hove, also for the Marine Parades and Sea Walls at Brighton, Hove, Bognor and other South Coast watering places, the most recently completed work of the class being the important Sea Defence Works at Seaford and Newhaven. Supplies have also been made to important Dock and Canal Works such as the Manchester Ship Canal, Tilbury and Southampton Docks, and the Alexandra Dock at Newport, Mon. The British Admiralty, when obtaining supplies of cement, specify particularly to tensile strain, fineness, specific gravity, and chemical analysis, and provide for the inspection of the cement at various stages. The Company have supplied the dockyards at Portsmouth, Devonport, and Pembroke Dock; also the Admiralty Works at Portland and Guernsey, and have given every satisfaction. The large blocks of Naval and Military Barracks constructed at Portsmouth during recent years have taken over 6,000 tons. Railway Works also account for large supplies of cement, and the Company has held the annual contract to the L. B. and S. C. Railway for 13 years. The modern application of concrete to drainage foundations, and flooring, has caused an increasing consumption of cement in every locality. Such buildings as the Hôtel Métropole (sic), Brighton (for which 2,000 tons were supplied), large Retort houses and Gas Holder Tanks at important towns, together with Drainage Works and Sewer Outfalls take a considerable portion of the Company's output. The Company has held the important annual contract of the Brighton Corporation for 14 years, and also those of Eastbourne, Folkstone, Torquay, Lewes, Plymouth, and other towns for varying periods. For the Manchester main drainage they supplied over 5,000 tons, and this year they are sending thousands of tons to the same Corporation for important Sewerage Works. Other important jobs now being supplied are the new East Sussex County Lunatic Asylum at Hellingly, the Glasgow main drainage, and the contract, extending over six years, for barracks at Tidworth, Salisbury Plain. This last is one of the largest and most important building contracts ever given out in this country, and the Company have arranged to supply the whole of the cement required.

THE COMPANY AND THEIR EMPLOYEES

One necessary outcome of the situation of the works at Newhaven and at Shoreham has been the springing up of miniature towns in both neighbourhoods. In both cases the works are practically isolated, and it has been with the object of having the bulk of their working population on the spot that the Company have erected rows of cottages for their occupation. Besides the cottages there are houses at both works for the works managers, the latter overlooking the works and thus commanding the whole situation. Some years ago a Sick and Provident Fund was started by which the men receive 12s. a week during illness and doctor's attendance when required; funeral allowances are paid to the widow or other relatives on the death of a workman, and to a man on the death of his wife. Near the Newhaven Works is a commodious Recreation and Reading Room with stage at one end. This stage can be used when entertainments are organised, and at other times can be partitioned off to form Committee rooms. Non-alcoholic refreshments and tobacco are supplied; there are billiard and bagatelle tables, and illustrated newspapers are provided without any expense to the men. During the winter months, entertainments are arranged by a committee elected entirely among the employees, and these are held in this Recreation Room. Moreover, the Company have at their own expense laid out a recreation ground for cricket and football. At the Shoreham works a mess room is provided for those men who come considerable distances. It will thus be seen that the Company have continued the enterprise and forethought they have displayed in prompting their business schemes to the people who work for them, and who benefit accordingly, and it is very probable that this consideration for their workmen has not been the least of those influences which have helped the works to attain their present position.

Pamphlet footnote: Since the foregoing article was written the company have acquired the old established Works of Messrs. Hooper and Company at Southampton, and the total combined output the works are now capable of is 125,000 tons per annum.

Between 1898 and 1903, the Sussex Portland Cement Co Ltd built 45 houses for their workforce just north of the Shoreham plant. The census returns for 1901 and 1911 show the development of these, and give an interesting insight into the nature of the workforce.

The fact that most of the houses were crammed with people - often with two housholds in a house, and numerous "boarders" and "lodgers" - is not surprising. It is typical of the housing in new industrial areas at the time. What its more striking is the cosmopolitan nature of the community, with workers drawn in from all over Britain.

The occupations listed indicate the nature of the workforce at a plant that at the time was still predominantly based on static kiln production. Many of those labelled simply as labourer probably had more specialised jobs than this implies. By far the most common specialised occupation mentioned is "kiln loader", digging dried slurry from the chambers of chamber kilns, and transferring it to the kiln for burning. In the 1911 census, there were also a number of contractors, working on the Kiln 3 installation, who had been billeted in the company housing.

The 1901 census took place on 31st March, and finds the development partially built, with 17 houses in occupation, and a further ten under construction. Many who subsequently moved in were at this time living in the surrounding villages. Svend Caspersen, one of two Danes supplied by F L Smidth, was staying with his wife in the same house as the chief engineer. These two came for the construction and commissioning of the first two rotary kilns, and stayed, on and off, for nearly ten years.

There were at this stage in total 92 people - 61 male and 31 female, the sex ratio indicating the large number of single male immigrants. There were 5.4 people per house on average minimum 2, maximum 8).

AddressNameAgeOccupationBirthplaceBirth County
Cliff HouseThomas Don32ForemanPlaistowLondon
1 Dacre GardensJames C Woolson29Kiln LoaderWarminghurstSussex
1 Dacre GardensWilliam F Kneller21TimekeeperBroughtonHants
1 Dacre GardensAlbert Double24ForemanSouthwickSussex
2 Dacre GardensHenry Masterson43Cement MillerIslingtonLondon
2 Dacre GardensAlfred Salmon29Fitter's MateBures St MarySuffolk
2 Dacre GardensEdwin Richards24Kiln LoaderShorehamSussex
2 Dacre GardensArthur Plumb22Kiln LoaderSudburySuffolk
2 Dacre GardensWilliam Snelling21FitterSouthwickSussex
2 Dacre GardensCharles Gibbs20Fitter's MateSnodlandKent
3 Dacre GardensJames Roberts38QuarrymanSteyningSussex
3 Dacre GardensWilliam G Cherriman22LabourerWest GrinsteadSussex
3 Dacre GardensCharles Cherriman19LabourerUpper BeedingSussex
4 Dacre GardensWalter Moase37Kiln LoaderParhamSussex
4 Dacre GardensThomas Clarke37Kiln LoaderBostonLincs
4 Dacre GardensEdward Hayles24BricklayerFindonSussex
5 Dacre GardensErnest J Chalcraft28Kiln LoaderSteyningSussex
5 Dacre GardensWilliam Avis38Engine FitterLambethLondon
6 Dacre GardensAlbert Elliott39LabourerStorringtonSussex
6 Dacre GardensLeonard Elliott16LabourerBotolphsSussex
6 Dacre GardensAbraham Hunt19LabourerBoxgroveSussex
6 Dacre GardensJoseph Kenyon32LabourerBurnleyLancs
7 Dacre GardensAlfred E House22LabourerBuckland NewtonDorset
7 Dacre GardensNelson House21Kiln LoaderBuckland NewtonDorset
7 Dacre GardensThomas House15Kiln LoaderBuckland NewtonDorset
7 Dacre GardensFrederick Woolen38WeighmanDevizesWilts
8 Dacre GardensRichard Nulley42StokerBrightonSussex
8 Dacre GardensFrederick Truegrow40LabourerHenfieldSussex
8 Dacre GardensJohn Brown49LabourerHastingsSussex
8 Dacre GardensHenry Gibbins50LabourerHastingsSussex
9 Dacre GardensEdward Terry45StorekeeperWindsorBerks
9 Dacre GardensEdward W Terry13Trolley boyHastingsSussex
9 Dacre GardensWilliam S Parker24LabourerBrightonSussex
10 Dacre GardensJoseph Holder23SlurrymanBrightonSussex
10 Dacre GardensHugh Campbell22Chemical AnalystCrieffPerth
11 Dacre GardensEdmund Packham45Engineering ForemanPimlicoLondon
11 Dacre GardensSvend Caspersen27Cement ExpertDenmark
12 Dacre GardensJohn O Brand28Engine FitterWickham MarketSuffolk
19 Dacre GardensGeorge Dick17LabourerFinsburyLondon
19 Dacre GardensJames Holder20LabourerHenfieldSussex
19 Dacre GardensThomas Woolgar18LabourerHenfieldSussex
20 Dacre GardensJoseph Mallinson30FitterLongwoodWest Yorks
21 Dacre GardensFrederick Hall46CarpenterLondonLondon
22 Dacre GardensAlfred Simmons25BricklayerBrightonSussex

The 1911 census took place on 2nd April, and by now occupancy was reaching a mature stage. There are many names among the residents that were familiar throughout the subsequent history of the plant.

There were at this stage in total 287 people - 163 male and 124 female. There were 6.4 people per house on average (minimum 3, maximum 12).

AddressNameAgeOccupationBirthplaceBirth County
Cliff HouseAlbert Double34ManagerSouthwickSussex
1 Dacre VillasAlfred S Shelbourne34Foreman FitterHitchinHerts
2 Dacre VillasWilliam Ollerenshaw50Electrical EngineerClayton-le-moorsLancs
2 Dacre VillasJames Keith Campbell26Chemical AnalystCrieffPerth
1 Dacre GardensJoseph Holder33MillerBrightonSussex
1 Dacre GardensBenjamin Brear32Civil EngineerAddinghamWest Yorks
1 Dacre GardensJoseph Brear18CarpenterAddinghamWest Yorks
2 Dacre GardensHedley Early41Engine FitterWantageBerks
2 Dacre GardensHarry Early16Electrician's MateWorthingSussex
2 Dacre GardensAlfred Salmon39Stationary Engine DriverBures St MarySuffolk
3 Dacre GardensWilliam George Brown41Kiln DrawerPoplarLondon
4 Dacre GardensWalter Moase47Rotary Kiln BurnerParhamSussex
4 Dacre GardensGeorge Moase17Laboratory AssistantBramberSussex
4 Dacre GardensThomas Clarke48Schneider Kiln BurnerBostonLincs
5 Dacre GardensErnest J Chalcraft39Kiln LoaderSteyningSussex
5 Dacre GardensHenry Thompson32LabourerBournemouthHants
6 Dacre GardensFrederick Carr29LabourerNutleySussex
7 Dacre GardensWilliam M Scott32Fitter's MateGlasgowLanark
7 Dacre GardensCharles Gladman36LabourerAngmeringSussex
7 Dacre GardensGeorge Gladman15LabourerAngmeringSussex
8 Dacre GardensJames Fieldwick37LabourerFletchingSussex
8 Dacre GardensFrank Pierce26LabourerWokingSurrey
8 Dacre GardensWilliam Skinner21LabourerBrightonSussex
9 Dacre GardensEdward Terry55StorekeeperWindsorBerks
10 Dacre GardensWilliam Langley35Stationary Engine AttendantHenfieldSussex
11 Dacre GardensJohn H May42Gas Plant OperatorBrightonSussex
12 Dacre GardensWalter T Dalton52Cement MillerDarenthKent
19 Dacre GardensAlfred Simmons35BricklayerBrightonSussex
20 Dacre GardensThomas Searle61LabourerStorringtonSussex
20 Dacre GardensThomas Searle31LabourerSteyningSussex
20 Dacre GardensErnest Searle23Engineer's LabourerSteyningSussex
20 Dacre GardensArthur Searle21Engineer's LabourerSteyningSussex
21 Dacre GardensJohn Silver44Cement MillerBethnal GreenLondon
21 Dacre GardensCharles French20LabourerLewesSussex
21 Dacre GardensWilliam Hipps19LabourerTollard RoyalWilts
21 Dacre GardensFrancis O Nellis23LabourerBethnal GreenLondon
21 Dacre GardensFrederick Douglas46LabourerBrightonSussex
22 Dacre GardensJohn Pearce47LabourerStroodKent
23 Dacre GardensEdward H Soughton31LabourerSeafordSussex
23 Dacre GardensArthur Williamson44Fitter's MateManchesterLancs
24 Dacre GardensGeorge F Champion28Crane DriverSwinefleetWest Yorks
24 Dacre GardensCharles J Fuller39LabourerHastingsSussex
25 Dacre GardensAlfred H Groves28Gas Engine AttendantUpper BeedingSussex
26 Dacre GardensAlfred H Thompson29ClerkBrightonSussex
26 Dacre GardensHarry A Jeffery34MillerSouthwickSussex
26 Dacre GardensHenry Masterson50Cement MillerIslingtonLondon
26 Dacre GardensGeorge Parker32LabourerArundelSussex
27 Dacre GardensCharles W Keywood26Kiln LoaderBramberSussex
27 Dacre GardensHenry Ashdown54LabourerTonbridgeKent
28 Dacre GardensWilliam A Waghorn40BlacksmithTunbridge WellsKent
29 Dacre GardensHarry Denyer26Gas Plant StokerShorehamSussex
29 Dacre GardensCecil E Thomas19Fitter's ApprenticeSouthamptonHants
30 Dacre GardensStuart Balding32BargeeTunbridge WellsKent
31 Dacre GardensCharles Cherriman29Kiln LoaderHenfieldSussex
31 Dacre GardensRichard Stillaway25Slurry ManShorehamSussex
32 Dacre GardensWalter J Hilder47LabourerWadhurstSussex
32 Dacre GardensWalter H T Hilder25LabourerWadhurstSussex
32 Dacre GardensGeorge J Hilder16LabourerPaddock WoodKent
33 Dacre GardensCharles Dance40PlatelayerSouthamptonHants
33 Dacre GardensRichard Sawyer33Kiln LoaderMaidstoneKent
34 Dacre GardensEdward Ransom28LabourerNewhavenSussex
35 Dacre GardensAlbert Newman36Coal MillerRomseyHants
36 Dacre GardensSydney H Thomas44LabourerWinchesterHants
36 Dacre GardensHerbert S Thomas15LabourerSouthamptonHants
36 Dacre GardensThomas E Gunn37ShunterBrightonSussex
37 Dacre GardensJohn Peachey35Gas Engine AttendantStratford St MarySuffolk
37 Dacre GardensMartin F Budgen23BricklayerBrightonSussex
38 Dacre GardensGeorge Goldsmith38FitterShorehamSussex
39 Dacre GardensJames F J Bridger34Foreman Cement LoaderWorthingSussex
40 Dacre GardensCharles W Upcott56CarpenterTopshamDevon
41 Dacre GardensCharles Boyce48Locomotive DriverBrightonSussex
42 Dacre GardensWilliam Parker40Rotary Kiln BurnerArundelSussex
43 Dacre GardensThomas R Barber35QuarrymanNewhavenSussex
43 Dacre GardensCharles Floyd20Laboratory AssistantActonLondon
44 Dacre GardensRichard F Akehurst37QuarrymanNewhavenSussex
44 Dacre GardensWalter Pepper28Contractor Pile DriverEssex
44 Dacre GardensJames W Parker26Contractor Pile Driver?
44 Dacre GardensGeorge Downey40LabourerExeterDevon
44 Dacre GardensWilliam G Holdbrook31Engine FitterLondonLondon
45 Dacre GardensJ Shepherd40StokerBristolGloucs
45 Dacre GardensI Parkinson29Contractors Clerk of WorksLittle LeverLancs
45 Dacre GardensG Apted50LabourerBrightonSussex
45 Dacre GardensH Linton29LabourerBrightonSussex
46 Dacre GardensGeorge A Akehurst38QuarrymanHeightonSussex
46 Dacre GardensCharles Comber25LabourerPortsladeSussex
47 Dacre GardensG W Lewis34Crane DriverAngmeringSussex
47 Dacre GardensWilliam Kinchell42LabourerSteyningSussex
48 Dacre GardensAlec Bailey36LabourerShorehamSussex
48 Dacre GardensFrederick Wood36LabourerCopthorneSussex

The 1959 Engineer article describes the kiln C3 slurry filtration system as the first in Britain, although the vacuum filtration system at Billingham had been in use for nearly 30 years. It was however certainly the first to use plate-and-frame pressure presses.

The project started in January 1955, and was completed 17 months later, indicating that it was commissioned in June 1956. There were three presses, each with 80 4 ft square plates, operating at 120 psi (827 kPa). Each was said to produce about 10 tons of cake per batch. The moisture content was said to be 18-19%, and 17-18 batches were completed every 24 hours, indicating a mean cycle time of around 82 minutes. Since cake of 18.5% moisture content has a density of around 2053 kg/m3, cakes of effective dimensions 46.5 × 46.5 × 1.75 inches would weigh 127 kg, and 80 of these would yield 10.19 tonnes of cake. The kiln averaged 235 tonnes/day of clinker, and probably made as much as 265 tonnes/day at peak production, requiring 539 tonnes/day of cake. Since the three presses were producing 540 tonnes/day, there was little overtaking capacity, and occasional down-time for filter cloth cleaning and replacement would have limited the kiln production.

Nylon filter cloths had been selected, and these were said to last for about 2000 cycles each, or 3000 cycles after repairs.

Original content © Dylan Moore 2011: commenced 05/01/2011: last edit 15/06/2017.

Return to plant list

HOME