Penarth

Penarth Logo
South Wales Portland Cement & Lime Dragon Brand. The Dragon brand remained in use well into the 1970s..

Location:

Clinker manufacture operational: 1889-1969

Approximate total clinker production: 5.0 million tonnes

Raw materials:

The following article appeared in the Western Mail (9/9/1889, p 34) and the Barry Dock News (13/9/1889, p 4) It proclaims the merits of the new process (the rotary kiln). The new process was patented (by Ransome) and its key element - the kiln - is not mentioned. In fact, other newspaper articles suggest that the locally-recruited workforce were kept entirely in the dark as to what was being attempted. The process was introduced, as at Mitcheldean and Barnstone, on a plant which was a new entrant to the industry, lacking any relevant expertise, and like those two plants, a dry process was employed. The motive power for the plant, and the heat for the kiln, were supplied by producer gas. The near-impossibilty of heating a kiln with producer gas ensured the failure of this and all the other Ransome kilns, although the article suggests it had been successful. By contrast, the 1895 article, with six years' hindsight, dismisses the whole project in half a sentence as an expensive failure. Knowledge of the way cement industry capital projects are vindicated teaches that at least six years' hindsight are needed before the claims of success can be seen for what they were.

SUPERLATIVE MERITS OF ABERTHAW LIMESTONE - THE CEMENT WORKS AT PENARTH

The importance of the works established by the South Wales Portland Cement and Lime Company, about half-way between Cardiff and Barry, does not seem to be generally known. The works are situated on the far-famed Aberthaw Lias beds (Note 1), which produce the best lime in England, and were erected for the purpose of making experiments on a large scale in the manufacture of Portland cement by a new process. We are informed that the experiments have proved to be in every respect successful. What has hitherto taken ten days from the quarrying of the stone to the production of the finished article has been done at these works in ten hours, the burning taking only one hour. It is also claimed by the company that the cement manufactured by the new process is superior to that produced by means of the old system. The cement can also be made according to the requirements of engineers—either for quick or slow setting—and is perfectly regular, being neither over- nor under-burnt. The plant will turn out about 200 tons weekly (Note 2), but that output could be easily doubled should the necessity arise (Note 3). The machinery has been purchased regardless of cost, and is, therefore, of the very best description. A powerful engine, 30 ft long, is being fixed, and will be fired with gas, which will do away with the trouble and expense of stoking (Note 4). A novelty in the shape of patent pulverising machines by Messrs. Pope Brothers, Bristol, is introduced. The drying fires have been laid down on the most approved principles, and economy in fuel is observed throughout the works. Two powerful gas generators by Mr B. H. Thwaite, Liverpool, supply the motive power, and work well. The experiments commenced last January, and have been carried on up to the present time. The tests which have been applied show that in seven days the cement will bear a pressure of 500 to 600 pounds to the square inch, and in eleven days it has borne a pressure of over 700 lbs. (Note 5)

The principal in the firm is Mr William Llewellyn Morcom, of Manchester and Penarth, and Mr Kilby, the manager, has now been taken into partnership.

On Saturday afternoon last, about 50 men employed at the works named dined together at the Ship Hotel, Penarth, and the chairman (Mr Morcom), in responding to the toast of his health, said that in all businesses time was money, and as this company could make clinker in the short space of one hour, which took a week to make by the old fashioned kiln system, and even longer than that by London and Kent manufacturers (Note 6), they might consider that they had taken the first step in revolutionising the whole trade of the world. Practical engineers would not be slow in recognising that, as the cement which this company would manufacture would be free from all admixture, it would go farther than ordinary kinds in the making of concrete. As they were aware, kilns built with alternate layers of stone and coke must, during the process of clinkering or fusion, combine a certain proportion of burnt coke with the cement, which had been estimated at no less than 14 per cent. (Note 7) The works at Penarth were the newest of the kind, and he anticipated that in time the output would rival the largest concerns in England. The London expert who had been consulted by the company, and whose opinion he valued more than that of any living man, said they had one fault, and that was that their stuff was too good, and that they were giving too much for the money. That was a fault which their buyers would not find a grievous one.

The following article appeared in the Western Mail (5/12/1895, p 7) and describes the plant before it expanded.

SOUTH WALES PORTLAND CEMENT AND LIME COMPANY (LIMITED).

A THRIVING LOCAL INDUSTRY.

One of the most thriving industries in this locality, and the only one of its kind in the Principality of Wales, is that of the South Wales Portland Cement and Lime Company (Limited), picturesquely situated in the fields midway between Penarth and Lavernock, and which deserves to be better known than it is, having regard alike to the quantity and the quality of its productions. Besides being the only cement works in Wales (Note 8), these are the largest Aberthaw blue lias lime works in the whole of the United Kingdom (Note 9). Having recently taken over the "Pebble Limeworks" at the Port of Aberthaw, the company now control the output of the finest hydraulic lime that the world produces. To speak of "pebble lime" to an engineer or architect is to awaken his interest, for who has not heard of this wonderful product? Cargoes of the "pebbles" are shipped almost daily to different parts of England for burning into lime, and even Australia has wanted a share! The Penarth works, which, with the quarries, cover nearly 60 acres, and give employment to 150 hands, were started single- handed by Mr W. Llewellyn Morcom, the present managing director, and laid out by Mr. W. J. Cooper, F.C.S. (Note 10), under whose management they have been developed and carried on with ever-increasing success. Mr. Morcom set the industry on foot in 1889, primarily with the object of trying the new process for making Portland cement in a revolving cylinder, which, however, proved to be a failure, after the expenditure of a large sum of money upon the experiments that were at that time carried out. For the past three or four years the company have made cement in an improved class of kiln, and now turn out an article equal to any manufactured in the kingdom. They are at present putting down plant for doubling the output, to meet the rapidly-growing demand. The lime business has also developed to such an extent as to justify, or rather to render necessary, the step the management has just taken in acquiring the works at Bridgend lately carried on by the Aberthaw Blue Lias Lime Company, and the arrangements they have also just completed for the working of the "Aberthaw Pebble Lime Company's" Works at the port of Aberthaw, which will enable the company to turn out 1,000 tons of Aberthaw Blue Lias lime weekly. Telephone communication has been established between the different works. which will be managed and controlled from the Penarth centre. Besides all this, ovens have been erected at the central works for the manufacture of plaster of Paris. There is a great demand for a good article, and this manufacture will, no doubt, prove to be as successful as that of lime and cement have already done.

The processes by which the rough stone and clay are converted into the manufactured Portland Cement are sufficiently interesting to describe. The stone and clay are conveyed from the quarry in trams to the works. On reaching the "crusher" they are weighed in their respective proportions, and are not again seen until they issue from the brick presses in the shape of blocks ready for burning. The blocks are stacked in chambers adjoining the kiln (Note 11), where they are dried by the waste heat, and then they are placed in the kiln with alternate layers of coke. Under temperature which is sufficient to melt iron, the blocks are fused into what is called "clinker". This "clinker" is in turn conveyed to the grinding department, whence the finished cement is conveyed by means of long screws to the warehouse, and there deposited in different bins, each kiln being kept separate for the purpose of testing. The warehouse holds 2,000 tons of cement, which will give an impression of the magnitude of the concern; and some idea of its development may be gathered from the fact that the output when the works were first started was only 50 tons a week (Note 12). A Western Mail representative, having occasion to see Mr. Morcom in his office, was courteously taken by that gentleman over the immense pile of buildings, which have a chimney stack nearly as high as those at the Dowlais Works. Access to certain of the departments is obtained by a lift; there is a commodious yard, and the quarries reach nearly to Lavernock. A visit was first paid to the laboratories, where the raw material and the finished article are carefully tested by Mr. A. E. Turner (chemist) and his assistant. The experiments made in the laboratories are of a most searching character. In addition to seven boilers, there are five engines, 700 horse power. The warehouse, already referred to as affording accommodation for 2,000 tons of cement, covers nearly a quarter of an acre. En route Mr Morcom pointed to a few of the specialities the works are able to produce. One of these was a very fine polished mosaic, made from cement. The artificial stone department is one of the largest, and it is worthy of notice that the company is now making paving slabs under an improved process which is in course of being patented (Note 13). These paving stones are becoming everywhere popular, and before long they will probably be used as extensively in Wales as they now are in London. The paving stones in Albany-road, Cardiff, must strike pedestrians as a very creditable specimen of the company's work. The stones are impervious to, and are not damaged by, frost. They do not wear away into holes which become puddles of water in the rain. The company have just laid 3,500 yards of this artificial stone for the Penarth Local Board at Penarth. and they have also supplied Cardiff, Bath, Cheltenham, Bristol, Neath and other places and give every satisfaction to the authorities of those towns. No fewer than 70 railway trucks are kept running to send material away to the different points of destination. The consumption of fuel amounts to from 150 to 200 tons a week. The warehouse and other departments were in turn visited, and it may be pointed out that these include a cooper's department, the firm making its own cement casks (Note 14). Tons of granite of different sorts are deposited in the yard and there is also a stack of gypsum, imported from Paris, for the plaster of Paris business, which is certain to develop into a very extensive branch. The stacks of artificial stone occupy thousands of yards. These slabs have a great reputation, not only for paving purposes, but (with engineers) for use as caps for pillars, steps, and copings, in the construction of railway platforms. Cement for fireproof flooring is also one of the company's specialities, which has been adopted, among other places, at the Cardiff Free Library and the "Western Mail" new buildings, St. Mary-street, Cardiff.

This article was included (pp 194-196) in the Handbook for the Cardiff meeting of the British Association, 1920. It describes the nearly fully-formed industry that emerged after the Great War.

Portland Cement Industry

By F. F. Miskin, A.I.C., F.G.S.

The greater portion of the coast of Glamorgan consists of almost vertical cliffs—in parts over 100 feet high—of Blue Lias Limestone and Shale. These rocks occur in alternate bands varying from one inch to two feet in thickness. The limestone is well jointed and the shale weathers readily; consequently by the action of the elements, blocks of limestone are perpetually falling from the cliffs, and the beach is covered with large round limestone pebbles that have been rolled by the waves of the Bristol Channel. At the mouth of the River Ddaw (Note 15) there is a great accumulation of Lias Limestone pebbles. These were found by Smeaton (the Eddystone Lighthouse Engineer) in 1756 to have hydraulic properties when burned to lime. The hydraulic properties are due to the fact that the Lias Limestone contains from 8 to 18% of silica and from 2 to 4% of alumina, and when burned, calcium aluminates and silicates are formed, which cause the lime to set to a hard mass after mixing with water and sand. Portland Cement is a hydraulic material of much superior quality and, unlike hydraulic lime, is non-expansive when mixed with water. Seven days after being gauged, it attains a tensile strength of 800 lb per square inch. Although hydraulic mortars were made in 1756, it is only since 1888 (Note 16), when the Penarth Cement Works were established, that the scientific development has been carried out in South Wales.

Portland Cement in this district is made from a very intimate mixture of finely ground Blue Lias Limestone and the chemically equivalent amount of aluminium silicate (Lias Shale) to satisfy the lime of the limestone. The Penarth Company was one of the pioneer firms to use the rotary kiln for burning the raw material, two of which were installed, each being 25 feet long and 5 feet diameter. This process was superseded by that of the intermittent (chamber) kilns, which in turn were supplemented by continuous vertical shaft (Schneider) kilns, and again these have been supplemented by a rotary kiln 230 feet long and 9 to 10 feet diameter.

For the fixed kilns (chamber and Schneider) the accurately proportioned prepared raw material is moulded into briquettes and burnt until incipient vitrification takes place, the resulting mass, technically known as clinker, being then finely ground, when it becomes Portland Cement of commerce.

For the rotary kilns the proportioned limestone and shale are broken down in large crushers into pieces the size of a walnut or less, then ground with water in large mills called "kominors" {i.e., steel drums, each charged with 5 tons of cannon balls) from which it issues in the form of a gritty liquid. The gritty liquid is further ground in a tube mill (a long steel cylinder lined with quartz and charged with flint balls) which gives it a creamy consistency. It is then finished in a short steel cylinder, containing steel pellets as grinding bodies. 97% of this "slurry" will pass through a sieve having 32,400 meshes to the square inch (Note 17). As it contains 36% of water, the slurry is stored in large masonry basins, where it is continuously automatically stirred to prevent settling. Powerful plunger pumps raise the slurry to the inlet end of the rotary kiln, which is a steel tube lined with special firebricks.

The kiln is mounted at a slight angle and rotated slowly on its own axis. The burning is effected in the kiln by the combustion of finely ground coal, blown in by an air fan at the lower end. A temperature of from 2,500° to 3,000° F is obtained. The heated products of combustion pass up the kiln and meet the liquid slurry flowing down, causing it to dry and break into small nodules, which continue their way into the "burning zone" where they are transformed into dense hard semi-vitrified pellets called clinker. The clinker escapes from the kiln white hot, and is shot into a large revolving tube called a "cooler" through which cold air is forced. In cooling the clinker the air becomes very hot and is used in the kiln to burn the coal and save fuel. The clinker, after storage in large silos, is conveyed to the cement mills, where it is coarsely ground in kominors or ball mills, and reground in tube mills (Note 18) so fine that 95% will pass through a sieve of 32,400 meshes to the square inch.

The foregoing describes the operations of the South Wales Portland Cement and Lime Co., Ltd., at their works at Lower Penarth. It is also interesting to note that the Aberthaw and Rhoose Portland Cement and Lime Co., Ltd., and the Aberthaw and Bristol Channel Portland Cement Co., Ltd., have factories situated at Rhoose and Aberthaw respectively, operating on the rotary principle, and the description of the rotary as set forth as being in operation at the South Wales Portland Cement and Lime Co., Ltd.'s works, is similar in the case of the other companies named.

In 1895 the output of cement in South Wales was approximately 5,500 tons. Today the quantity exceeds 200,000 tons (Note 19). The whole of the cement is made in close contiguity to the shipping ports of Cardiff, Penarth, and Barry, and there are excellent facilities for transport either by land or sea. The industry is carried on with unflagging enterprise typical of the busy district in which it is located. The reputation of the cement made in the district, all made to British Standard Specification, is firmly established.

NOTES

Note 1. The Blue Lias at Penarth is quite distinct from that at Aberthaw. At Penarth the Lias is from the St Mary's Well Bay Member (Planorbis Beds) whereas at Aberthaw it is from the Porthkerry Member (Bucklandi Beds) which is much higher in the sequence, and of considerably different chemistry.

Note 2. This was a Ransome claim, and was a vast over-estimate, even if the kiln had worked.

Note 3. A second kiln was added shortly afterwards.

Note 4. Of course, the gas producers needed stoking.

Note 5. These performance data might not have been self-delusion, but might have persuaded prospective investors. A clue might be the peculiar 11-day strength - maybe it didn't make it past that date! Similar encouraging data were supplied for the failed Gibbs installation.

Note 6. The implication is that settlement in slurry backs was still practised, but the Thames-side industry had largely abandoned this in favour of chamber kilns by this time.

Note 7. This ludicrous "estimate" was got up either by a moron or a crook - much more likely the latter.

Note 8. There was at least one other - Afonwen, but the North was a far-off country.

Note 9. The name of Aberthaw carried great prestige, and many Blue Lias lime works in South Wales far from Aberthaw used the term. The Penarth lime was particularly unlike that of Aberthaw, being much less siliceous and with higher alkalis. Probably this actually refers to the company, which had acquired two other suppliers, one actually at Aberthaw.

Note 10. Walter Johnson Cooper (b 1869 Walsall, Staffs; d. 27/5/1928 Paignton, Devon) had worked briefly as chemist at Arlesey 1887-1889, before moving to Mitcheldean 1889-1891 as manager, where he had the opportunity to see the by-then abandoned first rotary kiln. He then moved to Penarth as manager.

Note 11. These were much like the drying chambers used by Spackman at Barrow and Isis.

Note 12. The four chamber kilns probably made about 120 t/week.

Note 13. Manufacture of slabs from pressure-moulded granite concrete is another uncanny similarity to Barrow. Was Spackman involved?

Note 14. This was universally the case.

Note 15. Made-up name. It is either English Thaw or Welsh Ddawan.

Note 16. In fact, Portland cement was only made successfully in 1889, when static kilns were installed.

Note 17. This sieve size is pre-1931 180 mesh (96 μm). A modern process engineer would condemn this fineness as excessive.

Note 18. This antiquated arrangement continued in use until the plant closed in 1969.

Note 19. The capacity of the three plants had evolved as follows:

South Wales Clinker Capacity