CHAIRMAN'S ADDRESS - Coke Oven Managers Association

226. THE COKE OVEN MANAGERS’ YEAR-BOOK 

SIMPLEX COKE OVENS: THEIR HISTORY (PART 1) 

By 

Dr D G Edwards 

Introduction 

Coke ovens of Simplex design formed a small but significant proportion 

of the by-product coking plants erected in Britain in the first three decades 

of the twentieth century. Such plants were built at nine sites in England and 

two in Wales, but none in Scotland. The total number of by-product ovens 

constructed was 817, of which 473 were of the waste-heat type and 344 

were regenerative (Table 1) 1 . At five sites - Chilton, Newton Cap, 

Upholland, Ackton Hall and Clay Cross - Simplex ovens were the only 

type of by-product oven ever built. 

According to official figures 2 , the largest number of Simplex byproduct 

ovens actually in use during any calendar year was 523, in 1921. 

This was out of a total of 8146 by-product ovens in Britain, with Simplex 

ovens fifth in numerical order, after Otto-Hilgenstock (1993 ovens), 

Koppers and Simon-Carves (1707 each) and Semet-Solvay (1124), but 

ahead of Coppée (384), Huessener (379), Collin (126) and Still (72), with 

smaller numbers of other types making up the total. In 1938, Simplex, with 

375 ovens out of 5575 in use, occupied sixth place behind Otto- 

Hilgenstock, Simon-Carves, Koppers, Becker and Coppée. 

Simplex non-recovery ovens were also built at at least two sites in 

South Wales, evidently as an alternative to the more usual Coppée ovens: 

the Maritime plant had 130 such ovens by 1910 3 , and Rhymney Iron Co. 

had 50 built as late as 1915 4 . By 1920, only 58 of these ovens were 

reported 2 to be still in use, and none at all in succeeding years. 

Simplex ovens were also built in continental Europe. By-product plants 

which it has been possible to identify 5 were as follows: in Belgium, at 

Frameries (near Mons, installation destroyed in the Great War) and 

Selzaete (= present-day Zelzate near Ghent, 44 ovens started up 1926, 

visited by a C.O.M.A. group in 1927); in France, at Flers-en-Escrebieux 

(Douai, 88 ovens replacing an earlier Simplex plant destroyed in the Great 

War), Quiévrechain (near Valenciennes, 80 ovens) and Moyeuvre (NW of 

Metz, 60 ovens); and in the Netherlands, at Maastricht (90 ovens). One was 

Dr Edwards, now retired, was Information Officer, British Carbonization Research 

Association, 1962-1983 and is a freelance scientific editor.

SIMPLEX COKE OVENS: THEIR HISTORY (PART 1) - EDWARDS 227. 

also built at an unidentified site in Russia/Ukraine but was left 

uncompleted on the outbreak of war in 1914 6 . At least two non-recovery 

plants were also erected: at the ironworks begun in 1900 at Portoferraio on 

the Isle of Elba, Italy (104 ovens) 7 and at Enakievo in Ukraine (52 ovens 

built by 1903) 8 . 

County Plant NGR a 

Owners 

Ovens b 

Durham Chilton NZ2730 H Stobart & Co. 52 WH c 

Start-up 

date 

Final 

closure 

date 

1909 1938/9 

Fishburn NZ3631 H Stobart & Co. 50 R 1919 1954 

Lambton NZ3151 Lambton [&c.] Collieries d 35 R 1918/19 1938/9 

Newton Cap NZ2030 H Stobart & Co. 44 R 1914 1918 e 

Lancs. Upholland SD5003 Mountain Mine Colliery Co. f 35 WH c.1914 1930 

Yorks. Ackton Hall SE4220 Ackton Hall Colliery Co. 50 WH 1914 1939-45 

Hemsworth SE4115 South Kirkby [&c.] Collieries g 44 WH 1904/5 1929/30 

Derbys. Clay Cross SK4064 Clay Cross Co. h 34 WH 1905 c.1930 

16 WH 1907 c.1930 

23 R 1928/9 1953 

32 R 1932 1952 

Staveley SK4274 Staveley Coal & Iron Co. i 100 WH 1907 c.1922 

Glam. Bargoed ST1599/ 

SO1500 

Powell Duffryn Steam Coal 

Co. 

Trehafod ST0390 Lewis Merthyr Consolidated 

Collieries 

100 WH 1922 1965/6 

70 R 1925 1966 

50 R 1914 1920 j 

50 R k 1909 1919 

40 WH 1919/20 1929/30 

a National Grid Reference of 1 km square in which the plant lay; some uncertainty remains about the NGRs for 

Newton Cap, Hemsworth and Bargoed. b WH = waste-heat, R = regenerative. c Originally 50, rebuilt as 52 in 1920- 

2. d 1910, Lambton Collieries; 1913, Lambton & Hetton Colleries; 1930, Lambton, Hetton & Joicey Collieries. 

e Listed in the COMA Year-Book 1917 but not thereafter, inferred from ref. 68 to be still in operation at the end of 

1917. f 1916, Bispham Hall Colliery Co.; 1925, Upholland Coking & By-Products Co. g South Kirkby, Hemsworth 

& Featherstone Colleries Ltd. h 1913, Clay Cross Iron & Coal Co.; 1929, Clay Cross Coal & Iron Co. i 1950, 

Staveley Iron & Chemical Co.; 1962, Stanton & Staveley. j Rebuilt to Still design that year. k Originally 40. 

Table 1 

Simplex By-Product Coking Plants Built in Britain


The Simplex Companies 

The parent firm responsible for constructing Simplex ovens was 

established in Brussels on 16 June 1900 under the long-winded name of 

Entreprise de Construction de Fours à Coke et d’Usines Métallurgiques 

S.A. 9 . The name was changed on 9 August 1913 to Société de 

Construction de Fours à Coke ‘Simplex’. It was a public limited company, 

with an initial share capital of BF 648,000, which was increased in stages 

in 1906, 1920 and 1925 to BF 5 million (in 10,000 shares of BF 500 each). 

Its registered office was located at various addresses in Brussels from time 

to time. Like other such contracting firms, it had no fixed assets properly 

speaking; the plants that it built for clients were paid for either in 

instalments or out of the proceeds of the coke oven products over a period 

(the latter being a common arrangement for financing early by-product 

coking plants 10 ). It has not been possible so far to identify the original 

directors of the company, but in 1921, J.-H. Regnier-Oury was president 

and Frans Schepens, Ernest Druart and Firmin Linard were directors; all 

were apparently Belgian nationals. The present author has found only 

Linard’s name elsewhere in the literature (see later). The company was 

liquidated on 14 January 1930. It had never properly recovered its trade 

after the depression of the 1920s, having made substantial losses in each of 

the years 1926 to 1929 and not having paid any dividend to shareholders 

since 1925. No doubt its designs could no longer compete with those 

recently developed by other firms, such as those then offered by Coppée, 

Otto, Koppers, Simon-Carves and Woodall-Duckham: for example, the 

Wilputte ovens started up by Coppée at Consett in 1924 and the Becker 

ovens installed at several European plants in the 1920s. Such firms no 

doubt had a better marketing strategy and superior technical capability than 

the Simplex organisation possessed. It seems significant that another 

Belgian-controlled company, Chemicals & Coke Ovens Ltd, which offered 

the similarly outmoded Semet-Solvay oven design, was also wound up not 

long afterwards, in December 1932 11 . As regards the Simplex design, the 

words of no less an authority than Joseph Becker may be noted: in the early 

1920s he poured scorn on the Staveley Coal & Iron Company for installing 

a second plant of 100 Simplex ovens (see Table 1) which had if anything a 

lower coal throughput than the first 100, built 15 years earlier! 12 

This article deals more particularly with the British subsidiary of the 

Belgian firm, the Simplex Coke Oven and Engineering Company Ltd, 

whose coke oven building activities were at least equal in importance to the 

whole of the continental European Simplex activities. It was first 

incorporated in this country 13 on 14 May 1903 as a private limited


company, registered no. 77377, with its registered office at Temple Bar 

House (49 Cannon Street 8 ) in the City of London. Its Memorandum of 

Articles of Association 14 stated as its first object ‘To carry on in Great 

Britain and elsewhere the trades or businesses of manufacturers of coke, 

the manufacture or recovery of bye-products, oven builders, dealers in, 

builders and makers of machinery for washing, crushing, compressing and 

coking coal, and of other machinery and articles of any description in 

relation to which any process for the manufacture of coke or recovery of 

bye-products may for the time being be used or applied, the business of 

general engineers and contractors, and any other trade or business 

incidental to or arising out of the same or any of them ...‘. The nominal 

capital of the company was £5000, in 500 shares of £10 each, of which 

only £2 was initially taken up (and the same was true in 1908) 15 . The 

names of the shareholders and their holdings in 1903 and 1908 are given in 

Appendix 1 below. The present author has found none of their names in 

any other connection with coke ovens, so their interest in the Simplex firm 

was presumably purely financial. The first directors were three of the 

shareholders: Sigismund Charles Witting, Henry Robert Witting and 

Ludwig Wiese 16 . Of these, only H.R. Witting was still a director in 1908, 

together with Walter William White 17 . The company secretary in 1903 was 

another shareholder, Arthur Leopold White, and in 1908 was Tom 

L. Castle. 

In an article published in 1908, the firm was stated to be the agency for 

the Belgian company 18 . An office, apparently under the Belgian firm’s 

name, was also in existence in 1908 in Chesterfield, at 4 Glumangate 19 , 

which is explained by the company’s recent activity at Clay Cross and 

Staveley. In May 1909 the registered office was transferred to 

9 Southampton Street in Holborn 20 , and on 7 August that year it was 

resolved at an EGM that the company be wound up voluntarily, 

H.R. Witting being appointed liquidator 21 . This was evidently a 

restructuring measure, perhaps initiated by the Belgian parent firm, for on 

25 August Witting gave the Registrar of Joint Stock Companies notice that 

it had been agreed to register a new company under the same name of 

Simplex Coke Oven and Engineering Co. Ltd 22 . The formation of the new 

company was announced in the technical press in October; it was again a 

private limited company with a capital of £5000, but this time in £1 shares, 

4990 of which were held by the Belgian parent firm 23 . The new registered 

number was 105225 24 . Unfortunately the Companies House file on the 

resuscitated company appears to be one of those that have been destroyed 

as part of official policy, so information similar to that quoted above from 

the Board of Trade file on the original firm is unavailable.


Fig. 1 

The White Building, Fitzalan Square, in the centre of Sheffield 

(photograph by the author, 1991) 

On the 26th of November 1909, the first of a series of regular Simplex 

advertisements appeared in the Colliery Guardian, giving the address now 

as The White Building, Fitzalan Square, Sheffield. Occupying suite 36-40, 

the firm appears to have moved there since April that year. That large 

office block (Fig. 1) had been erected only recently (c.1908); it is a grade-II 

listed building and is faced with faience, including relief panels 

representing Sheffield crafts 25 . The company continued there for the next 

two decades, but its activity seems to have been wound down in 1928, 

when the then manager left the firm (see Personnel, below) and the 

business was transferred to agents, Chemical Engineering & Wilton’s


Patent Furnace Co. Ltd, which thereby acquired the rights to the 

construction of Simplex coke ovens in Britain and Australasia 26 . All the 

same, Simplex Coke Oven & Engineering Co. continued to place its own 

advertisement in the C.O.M.A. Year-Book in 1929 and 1930, though 

quoting both the Sheffield address and that of Wilton’s (Fig. 2). In the 

1931 Year-Book, Wilton’s no longer advertised Simplex ovens; the 

technology was evidently allowed to ‘die’ soon after the liquidation of the 

Belgian parent firm, although it was to be another year before the last 

Simplex ovens would be started up at Clay Cross (Table 1). 

Fig. 2 

Simplex Advertisement in the C.O.M.A. Year-Book, 1929


Simplex Personnel 

One of the directors of the Belgian parent company in 1921, as 

mentioned above, was Firmin Linard. Little is known of him at present, but 

more might be discovered. He was closely associated with René Fabry (see 

below) in the development of the earliest Simplex non-recovery and byproduct 

coke ovens, to the extent that these designs were sometimes 

referred to by the name ‘Fabry-Linard’; in fact, the company letterhead 27 in 

1904 read ‘The Simplex Coke Oven & Engineering Co. Ltd, Fabry-Linard 

System’. In a British patent specification (no. 23,056 of 1901) in the joint 

names of Fabry and Linard, describing the basic design of their nonrecovery 

ovens, Linard’s address is quoted as ‘Porto Ferraio (Island of 

Elba) Italy’. As mentioned above, 104 such ovens were erected about that 

time at the Elba ironworks; evidently Linard was supervising their 

construction and start-up. That is the only British patent with which his 

name seems to have been associated, and he receives no mention in the two 

main published histories of the coking industry 28 ’ 29 . 

Fig. 3 

René Fabry (from a photograph in Staveley News, April 1954)


Of Linard’s partner in those designs, René François Ferdinand Fabry 

(Fig. 3), we know a great deal more. He was born on 16 May 1877 in 

St Niklaas (St Nicolas), a town between Ghent and Antwerp; his parents 

were Edmond François and Leontine Victoire Fabry, Belgian citizens 30 . He 

was educated in Belgium, evidently qualifying as a civil engineer (which is 

how he described himself in many of his patent specifications), and in 1900 

was appointed constructional engineer with the firm of Dury & Bernard in 

Brussels, for whom he was engaged in the erection of coke ovens, coal 

washeries and blast furnaces in several countries before being appointed 

resident engineer in Britain for the Simplex company (although he 

obviously had a previous connection with it, through his association with 

Linard) 31 . The coke ovens built by Dury & Bernard (which became Dury & 

Piette in 1901) were non-recovery, of the modified Coppée type designed 

by Clément Bernard, an engineer who had earlier been employed by the 

Evence Coppée firm in Brussels 32 . In the 1901 patent specification referred 

to above, Fabry’s address appeared as ‘St Gilles Brussels’ (St Gilles is a 

district of the city, south of the centre), but whether that was his residence 

or the location of Dury & Bernard remains to be settled. 

In 1904, the year of Fabry’s appointment in Britain, the Clay Cross 

Company had eight trial coke ovens built by the Simplex firm to discover 

the most suitable chamber width for carbonising the slack from the Clay 

Cross collieries 33 . No doubt René Fabry supervised the erection and 

operation of these ovens and the construction the following year of the 

battery of 34 Simplex by-product ovens of a width chosen from the results 

of the trials. Evidently dating from this time is a picture postcard of Clay 

Cross Works, of which the present author has a commercially produced 

enlargement, bearing the following handwritten message in Flemish at the 

top of the picture: ‘Sister Marie. Clay-Cross / This is a view of the district, 

very fine. / Here is my office. [with an arrow pointing to a building more or 

less on the coke oven site]’ 34 . Fabry must have sent, or intended to send, 

the original postcard to his sister back home. About the same time, too, he 

would have been supervising the erection of the 44 Simplex by-product 

ovens at Hemsworth in south Yorkshire, and a little later, 1906-7, the 100 

such ovens in four blocks at the new Devonshire Works of Staveley Coal 

and Iron Company, north-east of Chesterfield. 

Early in 1906, René Fabry was elected a member of the Midland 

Counties Institution of Engineers 35 , his address being given as 24 Rue des 

Minimes, Brussels, a street in the city centre. It is uncertain whether that 

was a residence of his (implying that he did not yet consider himself 

permanently settled in England) or an office of the Belgian parent firm,


whose headquarters in 1908 however were at 9 Rue de la Régence, 

Brussels 36 , a street very near Rue des Minimes. Whichever is true, by 1907 

Fabry had made his home in Chesterfield, at Springwood House, 

3 Fairfield Road, a double-fronted detached house, still standing, only a 

short walk from Glumangate where the firm’s office was situated. When 

the office moved to Sheffield, Fabry went to live at Claremont, 

31 Devonshire Road, Totley Rise, now a suburb of the city but then in the 

parish of Dore, which was part of Derbyshire until 1934. In White’s 

Directory of Sheffield for 1910 he was named as managing director of the 

Simplex firm, and in that capacity he was responsible for dealing with 

further orders for Simplex coking plants: at Chilton, Fishburn, Lambton 

and Newton Cap in Co. Durham, Upholland in Lancashire, Ackton Hall in 

the West Riding, and Bargoed and Trehafod in South Wales, as well as a 

repeat order from Staveley and the non-recovery ovens at Maritime and 

Rhymney. And it was mainly from the Sheffield office that his patented 

designs emanated, all the specifications being in his own name, not that of 

the company; these concerned not only coke ovens and associated plant, as 

discussed later, but also the regulation of fuel supply to internal 

combustion engines (Brit. Pat. 14,416 of 1914), a four-stroke system for 

steam engines (Brit. Pat. 16,145 of 1914) and a linkage for motorcycle 

sidecars (Brit. Pat. 170,492 of 1920), but he was not the inventor of the 

Sheffield-built Simplex motorcar! Fabry never joined the Coke Oven 

Managers’ Association; perhaps he did not consider himself eligible. 

Neither René Fabry nor the Simplex firm appears in a list of donors for 

the relief of Belgian war refugees accommodated in Sheffield shortly after 

the Great War began in 1914, although it is possible that he was the 

anonymous ‘Friend of the Belgians’ who headed the list with the generous 

gift of £100 for the refugees and £100 for wounded Belgian soldiers at 

St John’s Hospital, Dore 37 . The Coke Oven Construction Co. (the then 

name of the British firm offering Semet-Solvay ovens, and based in 

Sheffield), with its obvious Belgian connection, donated £25. According to 

his obituary 31 , in 1922 Fabry was appointed general manager of the parent 

firm in Brussels, but whether this is correct or not, the following year his 

Simplex connection came to an end when he was approached by the 

Staveley Coal & Iron Co., with which he was of course already well 

acquainted, to become a technical adviser; later, in 1927, he became the 

firm’s chief design engineer, initially with the task of developing processes 

for cast iron pipe manufacture 38 . In conjunction with the Staveley 

company, he had two further patent specifications issued, one dealing with 

the coating of pipes with plastics (Brit. Pat. 416,967 of 1934) and the other


with regulation of the heating of annealing furnaces (Brit. Pat. 460,822 of 

1936). 

On taking up employment with Staveley, René Fabry moved home 

once again, this time to Dunmallet, 19 Cromwell Road, Chesterfield. While 

living there, on 30 March 1926 he became naturalised as a British citizen 30 . 

He was still there when the Chesterfield electoral register for 1931-2 was 

drawn up, with his wife Alice. Their daughter Vera was apparently born in 

late l912 39 and married Henry Bendy at Chesterfield parish church on 

14 March 1931 40 . By the time the electoral register of 1932-3 was drawn 

up, however, René Fabry and his wife had moved back to Devonshire 

Road, Totley Rise, this time to no.7. He died there at the age of 76 on 

2 January 1954 41 ; the funeral took place at Sheffield Crematorium on 

6 January (his ashes were scattered, and no memorial exists 42 ). According 

to his obituary 31 , up to his death he had remained technical adviser to the 

Staveley company, and had been ‘a man who lived for his work, a man 

whose ability and energy commanded wide respect, yet a charming 

companion who is sincerely missed’. 

Fabry’s successor at the Sheffield office of the Simplex company was 

H.O.H. Cerckel 43 , who was also of Belgian origin, it seems; he had been in 

charge of a Belgian coking plant in the first decade of the 20th century 44 , 

and before coming to Simplex he had been coke oven manager at 

Pinxton 45 . He left the company in 1928 to set up a consultancy at Alfreton 

in Derbyshire 46 - a move which presumably coincided with the transfer of 

the Simplex rights to Chemical Engineering & Wilton’s (see above). One 

of his interests was the manufacture of domestic coke in coke ovens 47 . He 

died in 1940 or 1941 48 . 

Another of the Simplex company’s engineers, who was perhaps 

second-in-command to Fabry and Cerckel, and possibly kept the Sheffield 

office running nominally for a couple of years after 1928, was Charles 

Auguste Baglin, a Frenchman. He joined the company in 1905, having 

previously been employed on coke oven projects by the Société Anonyme 

de Carbonisation (which built Carvès ovens) in Paris and then by the Otto- 

Hilgenstock Coke Oven Company in Britain 49 . He was evidently working 

for the latter firm by 1903, when a patent specification in his name (Brit. 

Pat. 7,448 of 1903, dealing with the gas/air supply to the heating flues in a 

Coppée-type oven) gave his address as 34 Fieldhouse Road, Balham, 

Surrey. In 1908-9 he was living at 14 Spring Bank Road, Chesterfield 50 , so 

he evidently had a hand in establishing the Staveley and Clay Cross coking 

plants. By 1912 he had moved to Sheffield, where he lived for many years


at 55 Dunkeld Road, Ecclesall. Whilst in Sheffield, he acted as French 

consular agent in the city from at least 1917 to 1944, in addition to his 

engineering career 51 . The date of his death has not been discovered. 

Two other names associated with the Simplex firm have been noted. 

Paul Parkinson, manager of the Shotton (Durham) coking plant, who died 

on 5 April 1918 aged 41, was said to have formerly been ‘guarantee’ 

foreman for Simplex, and to have spent four years in that capacity at the 

Staveley ovens 52 . In a description of the Staveley plant in 1909, it was 

stated that the Simplex company’s engineer was a Mr Wallis 53 , but no other 

reference to him has been found. Neither man is listed in Kelly’s Directory 

of Derbyshire for 1908, in contrast to Fabry and Baglin. 

Simplex Designs 

Unfortunately, no documents - tenders, contracts, drawings or 

correspondence - seem to have survived from the Sheffield office of the 

Simplex firm in local or national archives, and no trade literature from the 

company is held in the collections at the British Library (former Patent 

Office Library), Science Museum Library or any repository in the Sheffield 

region. For information on Simplex designs and plants we therefore have to 

rely on published articles, books and patent specifications. The company 

presumably relied on bricklayers, foremen etc. employed on an ad hoc 

basis for the construction of its ovens, as well as on other firms to provide 

and fabricate ancillary plant and structures. 

Coke ovens 

The Fabry-Linard design of non-recovery oven 8 (covered by Brit. Pat. 

23,056 of 1901) installed at the Elba ironworks, and presumably also in 

South Wales, was particularly intended for carbonising low-volatile coals, 

which (it was thought) needed a higher temperature (i.e. faster heating) to 

develop their coking capacity properly. At Elba the coal was of 18-23 per 

cent volatile matter, similar to that of South Wales coking coals. In this 

modified Coppée design (Fig. 4), with vertical heating flues in which the 

crude gas leaving the ovens was burnt directly, pairs of adjacent ovens 

were operated in tandem, one being charged half way through the 

carbonising period of the other. The gas leaving the top of the charge in 

one oven - the ‘heated’ oven - passed over into the free space of the other 

oven - the ‘heating’ oven - via ducts connecting the charge holes of the two 

ovens. The mixture of crude gas from the two ovens, which was


supposedly of constant quality (richer gas from one oven mixed with leaner 

gas from the other), then passed into the top of the heating flues in the wall 

on each side of the ‘heating’ oven, where it was burnt with air admitted via 

galleries in the roof of the battery. The waste gas made its exit through sole 

flues to the collecting flue and chimney. The ovens were thereby heated 

more intensively and uniformly, it was claimed. Dampers in the ducts 

between the charge holes could be closed while one of the ovens was being 

discharged, to avoid ingress of air into the other oven. With higher-volatile 

coals, it was suggested 8 , this type of oven would become too hot; for such 

coals, a design more similar to the conventional Coppée non-recovery oven 

would be recommended. 

Fig. 4 

Fabry-Linard non-recovery oven: simplified transverse section (based on Fig. 7 of ref. 8). 

Key: a ‘heated’ oven’ b, ‘heating’ oven; c, cross-over duct below chargeholes; d, combustion 

flues; e, air inlet ducts; f, sole flue. Note that the sections through the left- and right-hand 

pairs of ovens are taken at different points on the oven length.


The early Simplex by-product ovens installed at Clay Cross, 

Hemsworth, Staveley, Chilton, Ackton Hall, Trehafod (second plant) and 

Upholland were all of the waste-heat type, with horizontal heating flues 

(although this remains to be confirmed for Upholland), but there were 

some differences in detail. We shall take the Clay Cross ovens of 1905 as 

an example 33 . These had three horizontal flues, divided by a mid-feather 

half way along the heating wall (Fig. 5). Purified gas was conveyed from 

pipes running along the two sides of the battery top, to burners at the outer 

ends of the top and centre flues, as well as through the roof to the inner 

ends of the top flues. Combustion air was admitted around the upper burner 

nozzles at the battery sides, and through three openings in the roof, as 

shown. The waste gas left through openings at the inner ends of the bottom 

flues; that from the pusher side passed via a sole flue direct to the 

collecting duct leading to waste-heat boilers, whereas that from the coke 

side travelled via the sole flue of the adjacent heating wall. Three charge 

holes were provided for each oven chamber, although at Clay Cross, 

Hemsworth, Staveley and Ackton Hall (as well as the later Lambton plant) 

the coal was in fact stamp-charged. There was a single, central crude-gas 

offtake leading to a hydraulic main elevated above the battery. The arched 

oven chambers were 10 m long, 2 m high to the crown of the arch, and 

540 mm in mean width, with 38 mm taper. 

A similar design, but with fuel gas admitted only to the top flue via a 

gas-air mixing chamber, air admitted also to the bottom flue, preheating of 

the air by passage through the battery substructure, and two crude-gas 

offtakes, had been described previously 8 . The ovens at Hemsworth 54 and 

the first 100 at Staveley 55 seem to have been of much the same design as 

those at Clay Cross. However, at Chilton 56 the heating wall was nearer in 

design to that patented by Fabry in 1907 (Brit. Pat. 21,593), evidently 

representing another attempt to attain uniform heating with horizontal 

flues. A three-flue system was retained, but the mid-feather crossed only 

the two lower flues. Combustion proceeded from the outer end of the 

bottom flue on one side, via the centre flue on that side and the undivided 

top flue, to the centre and bottom flues on the other side. The flow was 

reversed periodically, the previous air inlet then serving as the waste gas 

exit. Coke oven gas burners were fitted at several points on the end walls to 

achieve uniform temperature over the heating wall.


Fig. 5 

Simplex by-product ovens at Clay Cross, 1905: simplified longitudinal section through heating wall (based on 

Fig. 1 of ref. 33). Key: a, fuel gas main; b, main burner; c, d, subsidiary burners; e, air inlet; f, g, h, combustion 

flues; j, waste gas exits; k, sole flue; l, connections from adjacent sole flue; m, main waste gas duct to boilers.


At Ackton Hall 57 and Trehafod 58 a ‘four-high’ flue system was used, 

with a mid-feather at the former (as at Clay Cross) but not at the latter. At 

Trehafod therefore, the combustion gases travelled the whole length of the 

heating wall in zigzag fashion from the top to the bottom flue; there were 

two gas burners in each end wall, but all the combustion air was introduced 

at the inlet end of the top flue. Better temperature regulation was claimed 

for this system, which was also featured in Christopher and Byrom’s 

book 59 with wording identical in part to that of ref 58, probably taken from 

a Simplex brochure. 

A peculiar attempt to improve the uniformity of heating in horizontally 

flued ovens was tried out at Hemsworth 60 and covered by one of Fabry’s 

patents (Brit. Pat. 5,801 of 1908; Fr. Pat. 400,849 of 1909). A cylindrical 

housing inserted into the fuel gas supply main contained a shutter rotating 

about an axis transverse to the main. This shutter interrupted the gas flow 

for two-thirds of each revolution, causing a series of alternate combustion 

and air zones to travel along the heating flues; it also caused pulsating air 

admission to the flues. The speed of rotation could be adjusted, to control 

the lengths of the combustion and air zones to achieve the best heating 

regime. Three such pulsators were installed at Hemsworth and were 

reported to be a success, enabling the coking time to be reduced from 38 to 

33 hours (for comparison, the coking time at Clay Cross in 1907 was 

36 hours 33 ). Best results, it was claimed, would be obtained by using the 

pulsators in combination with baffle plates at the ends of the flues, or with 

another feature patented by Fabry (Brit. Pat. 8,920 of 1909; Fr. Pat. 

413,301 of 1910). This latter feature involved widening of the flues 

towards the end away from the burner; the reduction in flow rate was 

supposed to aid combustion and mixing as the air and fuel gas became 

increasingly diluted by the combustion products. It is not known whether 

this feature was ever incorporated in any Simplex ovens. Moreover, the use 

of the pulsators was probably soon abandoned, although as late as 1919 it 

was apparently regarded by Eugène and Louis Lecocq 61 as an integral part 

of the Simplex horizontal-flue system, albeit one they seemed to find rather 

ridiculous. 

A waste-heat oven with vertical heating flues was also offered by 

Simplex 62 and was used in the second installation at Staveley: the 100 

ovens started up in 1922 63 . This was one of the earliest designs of underjet 

oven, with 28-32 vertical flues. Fuel gas burners were fitted in alternate 

flues and the combustion products flowed down through the adjacent flues, 

via a top horizontal flue. Extra gas burners at the ends of the top flue


maintained additional combustion in the end descender flues to avoid black 

ends. 

As seen in Table 1, Simplex regenerative ovens were built at five 

British plants in the second decade of the twentieth century, and later also 

at two other plants. No design details have been found for the Bargoed or 

Trehafod ovens, so which of the various heating arrangements were 

installed there is unknown. The Lecocq book 64 described the Simplex 

regenerative oven as having horizontal heating flues, but it is doubtful 

whether any British plant had such a design installed, unless the first ovens 

at Trehafod were of that type (if so, it is perhaps unsurprising that they 

lasted barely 10 years). One design of the more usual vertically flued 

regenerative oven was described by Christopher and Byrom 65 (Fig. 6). The 

regenerators ran the length of the battery, one at each side, separated by 

two air/waste gas ducts. The heating wall was divided half way along into 

two sets of 14 flues each, with a common top channel for each set. Fuel gas 

burners were located in the roof, one above each alternate flue division 

wall. Heated air from one regenerator ascended in alternate flues of one 

half-wall and the combustion products, containing excess air, descended 

the adjacent ones to a sole flue, from which they ascended alternate flues in 

the other half-wall, meeting further fuel gas in the top flue, and descending 

to the other regenerator. Thus a system of fractional combustion was 

maintained in the heating wall. No British Patent appears to have been 

taken out for exactly this design, which seems to have been the one 

installed at Lambton 66 , Newton Cap 67 and Fishburn 68 . It was also referred 

to by Mott 69 and by Blake Walker 70 . 

No details have yet been found of the Simplex regenerative oven 

designs installed at Clay Cross and Staveley in the 1920s and early 1930s, 

but those at Staveley had vertical flues 63 , and that was doubtless true of 

Clay Cross also. Possibly those at Clay Cross - or at least the final battery 

of 32 ovens - incorporated the heating system patented by Charles Baglin 

(Brit. Pat. 259,078 of 1926) and described in the technical press 71 . This was 

a hairpin (twin) vertical flue system with regenerators parallel to the long 

axis of the ovens, one under each oven chamber. Each pair of flues had 

three gas burners: one at the base of each flue and one at the top, in line 

with the dividing wall. Gas and air were admitted to the bottom of alternate 

flues in successive reversal periods, but gas was supplied continuously to 

the top burners, the. resulting secondary flames being drawn into the 

descending flue by the chimney draught. Thus in effect each flue was 

heated continuously, with the direction of combustion periodically 

reversed. The aim was to achieve more uniform and more intense heating.


Fig. 6 

Simplified cross-section of heating wall of vertically flued Simplex regenerative oven as installed at Lambton and Newton Cap 

(based on Fig. 68 of ref. 65). Key: a, fuel gas main; b, burners; c, rising combustion air flue; d, descending first-stage 

combustion flue; e, rising first-stage combustion products flue; f, descending second-stage combustion flue; g, transfer port from 

one half-wall to the other; h, air regenerator; j, waste gas regenerator; k, main air flue; l, main waste gas flue. After reversal, the 

functions of c and f, d and e, h and j, and k and l are interchanged.. 

(To be continued)


As at 2 June 1930: 

Appendix 1 

Shareholders in the Simplex company 

No. of 

shares 

Frederick Charles, Littlegrove, East Barnet, Herts., merchant 1* 

G.H. Cornelson, 16 Rue St Marc, Paris, merchant 40 

Cornelius Deronde, 45 Marmora Road, Honor Oak, London SE, accountant 1 

Alfred Cecil Eborall, Kirkstall Lodge, [115] Tulse Hill, London SW, engineer 20 

Arthur Leopold White, Seymour House, Acton, London W, clerk 1 

Walter William White, Seymour House, Acton, London W, chemist 1 

Ludwig Wiese, 4 Whitehall Court, London SW, merchant 50 

Henry Robert Witting, Seymour House, Acton, London W, company secretary 200 

Sigismund Charles Witting, Hollingbury Copse, Patcham, Sussex, merchant 186 

As at 13 October 1908: 

Henry Robert Witting, Grange Park, Ealing, London W, company director 443 

Walter William White, 6 Lyncroft Gardens, Ealing, London W, engineer 51 

Tom L. Castle, 152 Upper Richmond Road, East Sheen, London SW 4** 

Mrs Alice F. Witting (same address as H.R. Witting) 1 

Mrs Lilian F. White (same address as W.W. White) 1 

* Transferred on 2 July 1903 to Sigismund Charles Witting. 

** Until 29 September 1908 these shares had been held one each by Edwin L. Mitchell 

(Yalding House, Acton, London W, civil servant), Charles W. Hogg (20 Anson Road, 

Cricklewood, company director), Dangan E. Wagenreider (8 Inglis Road, Ealing, 

London W, occupation unstated) and Arthur Leopold White (144 Vincent Street, Glasgow, 

traveller; evidently the same man as in 1903). 

Acknowledgements 

I am very grateful to M. Pascal Lefèbvre, Directeur, Maison de la 

Métallurgie, Liège, for kindly supplying me with photocopies of references 

6 and 9. I also thank Mr Philip Riden for enquiring at Companies House 

for records of the Simplex firm (ref 24), and for examining René Fabry’s 

naturalisation certificate at the Public Record Office (ref. 30). 

Miss S.E. Clarke at the Home Office kindly consulted Fabry’s 

naturalisation file (not yet available to the public), which did not yield any 

further information of substance. Ms Diane Gascoyne, whose article on the 

Belgian refugees in Sheffield appeared in Sheffield History Reporter 

Annual, 1998, 51-8, was good enough to send me a copy of ref. 37.


I have made considerable use of the library facilities at several places, 

particularly BCRA Scientific & Technical Services Ltd, Wingerworth, the 

University of Sheffield and Leeds City Patents Information Unit, to which I 

am indebted for much of the information in this article. 

References 

1. D.G. Edwards, A Historical Gazetteer and Bibliography of By-product Coking 

Plants in the UK, Merton Priory Press, 2001 

2. Secretary for Mines, Annual Reports, 1905-1938, HMSO, London 

3. Iron Coal Trades Rev., vol.80, 13 May 1910, 769 

4. Gas World, Coking Sect., 1 Jan. 1916,20 

5. C.O.M.A. Year-Book, 1924-5 and 1935 (lists of plants) 

6. Recueil Financier (Bruxelles), 28th year, 1921, 711 

7. Iron Coal Trades Rev., vol.66, 20 Mar. 1903, 751-2; J. Nebelung, Z. Ver. Dtsch. 

Ing., vol.47 no.43, 1903, 1559-67 (in German) 

8. Iron Coal Trades Rev., as in ref 7 

9. Recueil Financier (Bruxelles,), 28th year, 1921, 711-12; 37th year, 1930, vol.11, 

697-9 (sources for much of the information in this paragraph) 

10. D.G. Edwards, C.O.M.A. Year-Book, 1998, 260-8 

11. London Gazette, 1932, vol.4, 8244 & 8350 

12. C.O.M.A. Year-Book, 1922-3, 148-9 

13. Public Record Office, Board of Trade, Companies Registration Office, Files of 

Dissolved Companies, BT 31/10298/77377 

14. Ref 13, document 77377/4 

15. Ref 13, documents 77377/8,77377/16 

16. Ref 13, document 77377/7 

17. Ref 13, document 77377/16 

18. Iron Coal Trades Rev., vol.95, 26 June 1908, 1204 

19. Kelly’s Directory of Derbyshire, 1908 

20. Ref 13, document 77377/17 

21. Ref 13, document 77377/18 

22. Ref 13, document 77377/20


23. Colliery Guardian, vol.98, 15 Oct. 1909, 798 

24. Index at Companies House, Cardiff 

25. Department of National Heritage, Revised List of Buildings of Special Architectural 

or Historic Interest. City of Sheffield, South Yorkshire, 1995, pt.I, 315 

26. Iron Coal Trades Rev., 17 Aug. 1928, 246; Gas World, Coking Sect., 1 Sep. 1928, 

19 

27. Ref 13, unnumbered letter dated 1 October 1904 from H.R. Witting to the Registrar 

of Joint Stock Companies 

28. R.A. Mott, in The History of Coke Making and of The Coke Oven Managers’ 

Association, Cambridge, 1936 

29. F.M. Ress, Geschichte der Kokereitechnik, Essen, 1957 

30. Public Record Office, HO 334/102/13198 (Home Office copy of Fabry’s 

naturalisation certificate; information kindly supplied by Philip Riden) 

31. Staveley News, vol.3 no.2, April 1954, 94 (Fabry’s obituary) 

32. F.M. Ress, ref 29 above, 148 & 455 

33. W.B.M. Jackson, Trans. Fed Inst. Mining Engineers, vol.33, 1906-7, 386-97 

34. Print purchased from the stall of J.M. Roper, Chesterfield Market; unfortunately 

they seem to have lost or mislaid the original postcard, so whether there was a 

further message and/or address on the reverse is unknown 

35. Trans. Fed Inst. Mining Engineers, vol.30, 1905-6, 578 

36. As quoted in an article in Engineering on the Devonshire Works of Staveley Coal 

&. Iron Co. (ref 55 below) 

37. Sheffield Daily Independent, 24 Oct. 1914, Public Notices (information kindly 

supplied by Diane Gascoyne, whose article on the refugees appears in Sheffield 

History Reporter Annual, 1998, 51-8) 

38. S.D. Chapman, Stanton and Staveley: a Business History, Cambridge, 1981, 143-5 

39. General Register Office, microfiche index of births registered Oct.- Dec. 1912: Vera 

M. Fabry registered at Reading (ref. 2c, 640); mother’s maiden name quoted as 

Foster. No registration of René and Alice’s marriage appears in the GRO’s indexes 

for Britain or British consulates between 1901 and 1914 inclusive; where and when 

this marriage took place remains unknown so far. 

40. Chesterfield Public Library, Chesterfield Family History Society index (extract 

from Chesterfield Parish Church Magazine) 

41. The Times, Tuesday, 5 January 1954, 1 (classified announcements) 

42. Ascertained by personal enquiry at the crematorium office 

43. Gas World, Coking Sect., 2 Sep. 1922, 11; Kelly’s Directory of Sheffield, 1925 (the 

1923 edition mistakenly still names Fabry as manager) 

44. C.O.M.A. Year-Book, 1935, 84


45. C.O.M.A. Year-Book, lists of by-product coking plants each year 

46. Gas World, Coking Sect., 7 Jan. 1928, 10 

47. H.O.H. Cerckel, C.O.M.A. Year-Book, 1935, 82-105 

48. C.O.M.A. Bulletin, vol.XII, no.3, 1941; death also announced in C.O.M.A. Report 

of Council 1940-41 (year ended 30 September 1941) 

49. Iron Coal Trades Rev., vol.118, 11 Jan. 1929, 39 

50. KelIy’s Directory of Derbyshire, 1908; Brit. Pat. 9,405 of 1909 (discussed in the 

section on Simplex designs) 

51. Kelly’s Directory of Sheffield, various dates in the period mentioned 

52. Gas World, Coking Sect., 4 May 1918, 21 (obituary) 

53. Colliery Guardian, vol.98, 24 Dec. 1909, 1283 

54. Gas World, Coking Sect., 6 Sep. 1913, 15-17 

55. Engineering, vol.85, 1 May 1908, 571, 573-6, 586 + Plate XL 

56. Iron Coal Trades Rev., vol.79, 19 Nov. 1909, 816-17 

57. Gas World, Coking Sect., 3 Oct. 1914, 10-12 

58. W.T. Lane, Colliery Guardian, vol. 119, 25 June 1920, 1785-9 

59. J.E. Christopher and T.H. Byrom, Modern Coking Practice, 3rd. ed., London, 1921, 

vol.1, 107-8 

60. Iron Coal Trades Rev., vol.81, 15 July 1910, 81 

61. E. and L. Lecocq, Les Fours à Coke, Paris, 1919, 360 

62. J.E. Christopher and T.H. Byrom, ref 59 above, 109-10 

63. Iron Coal Trades Rev., vol.128, 6 Apr. 1934, 568-74 

64. E. and L. Lecocq, ref 61 above, 358-64 

65. J.E. Christopher and T.H. Byrom, ref. 59 above, 109-11 

66. G.P. Lishman, C.O.M.A. Year-Book, 1919, 108-10 

67. F.C. Coleman, Colliery Guardian, vol.108, 18 Dec. 1914, 1267-71 

68. Gas World, Coking Sect., 5 Jan. 1918, 18 

69. R.A. Mott, Fuel, vol.4, 1925, 310 

70. G.B. Walker, Min. Proc. Inst. Civil Engineers, vol.205, 1917-18, 114-16 

71. Iron Coal Trades Rev., vol.118, 11 Jan. 1929, 39

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