Wyllie (ST 1764 9335)

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The colliery was originally planned for Gelligroes a mile further up the valley but this site was abandoned due to excessive water during the sinking, this delay, and then the outbreak of war made Wylie Colliery the last deep mine to be sunk in Monmouthshire, and one of the last in south Wales. There was no proper road to the site and one nearly a mile in length was constructed between December 1923 and the end of 1924 when work started on the surface of the mine.

In July 1924 the report on Wyllie Colliery was;

Good progress has been made, despite the bad weather, with the preparatory work connected with the company’s new sinkings, which the directors have been good enough to honour me by naming the Wyllie Colliery. An approach road about two miles in length has been completed and gives access to the colliery on the west side of the Sirhowy River. The junction connecting the colliery sidings with the London Midland and Scottish Railway have been laid down and will shortly be available for use. This will enable us to proceed with the erection of the necessary sinking equipment for the two shafts it is our intention to proceed with at once. The somewhat heavy excavation work for the colliery surface works and sidings is well advanced. We expect to commence actual sinking work during the next few months. The colliery will be electrically equipped throughout, and the laying of the necessary power cables connecting the colliery to our Oakdale power station is well in hand. Provision has been made for a colliery village near the pits, and it is expected that a certain number of houses will be commenced this autumn.

 The Tredegar Iron and Coal Company’s prospectus for July 1926 reported that the pit had been sunk to 386 yards and it had reached the Big Vein seam which was 73 inches thick at a depth of 323 yards. The Upper Rhas Las had just been reached and this was the seam that they intended to work first. Although they were carried on down to the Old Coal seam so as to prove all the seams. The surface workings had been completed with the powerhouse finished, two electric winding engines, compressors, ventilating fans and switchgear all in working order. The headgear frames had been erected and the power lines from Oakdale Colliery completed.

The sinking of the South Shaft began on the 7th of November 1924 and was completed on the 30th of August 1926. Fifty yards to the north, the North Pit was sunk between the 13th of January 1925 and the 21st of September 1926. The South shaft was 629 yards deep and was the upcast ventilation pit and the North shaft was 598 yards deep and was the downcast ventilation pit, both were 20 feet in diameter with the headgear being 68 feet high and the sheaves 16 feet in diameter. Winding capacity was two trams per wind. Electric winders were installed from the onset. They were constructed by Siemens & Chucker (electrical parts) and Markham & Co (mechanical parts). The winding motors were 1,562 h.p. at 6,600 volts. The electrical generator had a 22.2 ton flywheel which produced 6.600 volts. Its diameter was 14.5 feet. The winders were designed for an ultimate output of 171 tons per hour at a maximum speed of 61.6 feet per second. The main electrical supply for this colliery was by underground cable from Oakdale Colliery 3.5 miles away. Ventilation was by two Oerlikon cascade-connected motors of 550 hp driving a Sirocco fan of 140-inch diameter which gave out 403,000 cubic feet of air per minute.

The colliery was equipped with a storeroom, electricians, fitters, smiths and carpenters shops. A Lamproom was constructed with provision for 200 oil and 2,000 electric lamps. The screening plant consisted of three tumblers with two picking belts. The winding engines, fan motors, air compressors, etc, were housed in one building 283 feet long and 41 feet high. Two 450 hp centrifugal pumps capable of pumping 42,000 gallons of water per hour were installed in the 390 Yard seam lodge room, at the 570 Yard level there was a 75 h.p. Sulzer pump capable of pumping 15,000 gallons per hour plus a compressed air pump as a standby.

Due to the difficult geology encountered the company found great difficulty in identifying the coal seams in relation to other local collieries. Initially, they were named after the depth that they were found. Therefore the Four-Feet seam was called the 510 Yard, the Six-Feet seam was called the 520 Yard, the Nine-Feet seam was called the 530 Yard, the Bute seam was the Yard, the Yard/Seven-Feet was the 570 Yard and the Five-Feet/Gellideg seam was called the 580 Yard seam.

The TIC prospectus for July 1927 reported that most of the steel used to build Wyllie colliery was made at their own works. The shafts had just been completed and they were opening out ‘vigorously’ and winding coal from the 570 yards seam. The north shaft by then was completely equipped.

Wyllie Colliery only worked the 570 seam for the first five years of its life. It then continued to work this seam but also ventured into the 520 seam. By the 6th of July 1928, output had risen to 7,000 tons of coal a week with the coal being of ‘excellent quality’, the company was particularly proud that no horses were employed at the colliery. The Tredegar Iron and Coal Company prospectus in June 1928 stated that:

The output at the Wyllie Colliery is now 7,000 tons per week. The seam is of excellent quality, and it is really a first-class colliery. Its development is proceeding satisfactorily, and the second shaft is completely equipped for winding.

On the 9th of March 1928, Joseph G. Haines, Age: 17 years and a colliers helper, died under a fall of roof.

On the 18th of September 1929, two hundred members of the South Wales Institute of Engineers visited this pit to examine its modern layout. A year later and the depression in the demand for coal caused the Tredegar Company to introduce short-time workings in all their pits bar Markham, with over a thousand men being laid off. On top of this, the 1,200 men at Wyllie Colliery came out on strike over the dismissal of two men and a boy. Both their own union and management refused to talk to them until they returned to work and the dispute fizzled out. The washery was installed in 1930 and had the capacity to wash 125 tons of coal each hour.

On the 25th of May 1933, Ronald Baldwin, aged 20 years, and a colliers helper died under a Fall of the roof.

By 1935 the colliery was managed by AM. Strong and employed 91 men working on the surface and 870 men working underground.

In 1938 and 1945 the manager was D.H. Thomas. In August 1939 this colliery was working the 570 yards seam from the West, New East and North East Districts which gave a daily output of coal of 881/1,400 and 789 tons respectively. The 530 yards seam was worked from the North West and West Districts which produced 685/1,079 tons of coal daily. The 520 yards seam was worked from the East District and produced 266 tons of coal daily.

In 1943 it employed 616 men working underground in the 5/20, 5/30 and 5/70 seams and 113 men working at the surface of the mine.

In 1944 a canteen was constructed with funds granted from the Miners Welfare Committee.

In 1946 the underground electrical haulage engines consisted of two 300 hp engines, one 100 h.p. engine and five 40 h.p. engines. There were also seventy compressed air haulages which varied between 25 to 80 h.p.

In a series of leaflets detailing all their collieries, the TIC had this to say about Wyllie Colliery;


April, 1946


Wyllie colliery situated in the Sirhowy valley, about one mile south of Pontllanfraith, is the property of the Tredegar (Southern) Collieries Ltd., which is a subsidiary company of the Tredegar Iron and Coal Co. Ltd.

The sinking was commenced in 1924 and completed in 1926.

There are two shafts. South (upcast) and North (downcast) are both 20 ft. diameter and sunk to a depth of 598 and 627 yards respectively. Coal is wound from the 570 yard level in the North pit, and from the 520 Yard level in South pit.

The equipment of each shaft is identical.

The headframes of lattice steel are 60’ high to the centre of the sheave and are by Messrs. Rees & Kirby, Morriston. Sheaves are 16’ in diameter and built in halves. Guides are locked coil 1½” diameter, four to each cage, and there are also two 1¾” rubbing guides between the cages. Cages are single deck, two trams on the deck, each holding 27 to 28 cwts of coal. Winding ropes are flattened strand 1¾” in diameter. Bein keps are also fitted at each shaft.

The Colliery is electrically equipped throughout. The principal supply is obtained from Oakdale Colliery, some 3½ miles to the north, by means of two 6-core split conductor underground cables with cores of 0.125 sq.in. section, current being transmitted at 6,600 volts, 50 cycles, 3-phase. The system is also connected with the South Wales Power Co. there being installed 11,000:6,000 volt transformer.

Main Enginehouse


This is entirely electrical and on the Ligner system with Ward Leonard control. The electrical portions are by Messrs. Siemens Shuckert and the mechanical parts by \Messrs Markham & Co.. Chesterfield. On each winder, a spare motor is installed. Both converter sets run at 570:490 r.p.m. and each consists of an alternating current motor, 1,562 h.p. , 6,600 volt, variable voltage D.C. generator and a 20.2 ton flywheel of 14.45’ diameter. The winding motors are direct current 1,590 h.p. maximum speed 65.4 r.p.m. The winding drums are semi-conical rising from 12’ to 18’ in diameter.


The screening plant is of Messrs Plowright Bros., Chesterfield, manufacture and consists of three coal tumblers, with two picking belts of standard South Wales type and a third fitted with jigging screen for production of special coals. Conveyors are so arranged that small coal can be delivered direct to wagons or sent to washery.


This is on the “Baum” principle and was erected by Messrs. Simon Carves in 1930. The plant has a capacity of 125 tons per hour of all coals up to and including 2 ¼”, and extensive sizing and mixing arrangements are incorporated.


No locomotive is required, all sidings being worked by gravity. Wagons required on pit bank are handled by rope haulage.


The shaft cables consist of two 3,300 volt, 3 phase power cables of 0.15 sq. in section, one in each pit. Each pit also has a separate shaft signalling and telephone cable, An additional two core 220 volt cable in the North shaft provides for underground lighting.


The main makes of water are met above 390 yard seam, and at this level are installed two 8-stage Mather & Platt centrifugal pumps, each of 42,000 g.p.h. capacity driven by 450 h.p. motors.

At the 570 Yard level one 7-stage Sulzer centrifugal pump of 15,000 g.p.h. capacity and driven by a 75 h.p. motor, is installed for pumping into the 390 Yard standage. Also at this level is one 15” . 6” . 24” Joseph Evans compressed air reciprocating pump which acts as a standbye. It has a capacity of 7,340 g.p.h. and also delivers into the 390 yard standage.


The main haulages are electrical principally of Messrs. Markham & Co., construction with Oerlikon or E.E.C. motors.

There are in use:-

2 – 300 h.p. haulages

1 – 100 h.p. haulage

5 – 40 h.p. haulages.

Electrical and mechanical portions of each of the above sizes are standardised. There are 70 compressed air haulages of 25 to 80 h.p. capacity also in use inbye.

A third M.G. set without flywheel acts as a standby that can be connected to do service with each winding gear.


Two Oerlikon cascade-connected 5-speed motors, maximum h.p. 550, driving Sirocco type fan 140” diameter, built by Messrs. Davidson, capable of producing 403,000 c.f.p.m. of air at 5.05” w.g. The ventilating plant is therefore completely duplicated.


Three 3,000 c.f.p.m. Bellis & Morcom direct coupled to 600 h.p. E.E.C. motor. Cooling of circulating water is maintained by a Visco cooling tower.

There are also installed several motor-generators for lighting and for charging miners’ lamps and the storage battery which is installed as a standby for lighting and other purposes.


This is installed in an annexe at the front of the main building and consists of 6,600 volt., 3,300 volt., 550 volt., and 220 a.c. boards of the Reyrolle ironclad totally enclosed mining type.

The necessary transformers for reducing current are placed in a separate building external to the power house. The transformers consist of two step-down transformers, 6,600/3,300 volts, each of 1,000 k.v.a. capacity, all of Metro-Vickers manufacture; and one transformer 11,000/6,600 volts of 2,500 k.v.a. capacity of E.E.C. manufacture.

Surface Arrangements

Colliery Stores.

There is a provision for both heavy and light stores under the eye of the storekeeper.


These include electricians shop, fitting shop with lathes, drilling and screwing machines etc. Smiths shop with shears, steam hammer etc., and carpenters shop.


This contains provision for 200 oil and 2,000 electrical lamps. Concordia electric lamps and Thomas & Williams No.1 flame lamps are in use.

Underground Workings

At present, due to depletion of manpower, all work is concentrated in two highly mechanised districts of the 530 Yard seam, and one of these is shortly to be installed with a large electrically driven trunk conveyor.

The entire output, for the first 4 or 5 years of the colliery, was obtained from the 570 yard seam, and both this and the 530 yard seam are made readily available for future development.

The colliery has been fully mechanised for some years, the entire output being hauled by conveyors and a large proportion of it machine cut.

The colliery remained in the hands of the Tredegar Company until Nationalisation in 1947 when the colliery was placed in the National Coal Board South Western Division’s, No.6 (Monmouthshire) Area, Group No.3, and at that time employed 126 men working on the surface of the mine and 639 men underground working the Five-Thirty- Yards, and Five-Twenty-Yards seams. The manager at that time was PG. Weekes. This did little to improve industrial relations at the colliery, though, and almost immediately 800 men at Wyllie went out on strike because five men didn’t receive their bonus due to arriving late for their shift. They were then paid, it came to £5 between the five of them.

In 1951 a shortage of manpower at this, and Nine Mile Point Colliery prompted the NCB to place the following advertisement in the South Wales Argus:


Faceworkers/Miners earn £8 to £12 a week. The average earnings of skilled faceworkers in British coal mines are between £8 to £12 a week and many of these men were new to the industry only a few years ago. Mining today gives you every chance to train for a skilled job – in a vital industry that will always be wanted.

Good wages from the start.

Trainee of 21 years and over start at £5.10.0 a week rising to £6.70 after three weeks on transfer to underground work There are other advantages too – extra rations, good canteen and plenty of scope for sports and recreation. How about you

Talk it over now at your Employment Exchange or with the Training Officer at any of the Collieries where there are vacancies.

By 1954 the same seams were being worked but manpower had risen to 140 working on the surface of the mine and 723 men working underground. The manager was now H.L. Nash. In 1955 out of total colliery manpower of 857 men, 389 of them worked at the coalfaces, in 1961 these figures were 665/307 men respectively.

In 1964, and the aura of uncertainty caused by the apparently random way that collieries were closed created a despondency amongst the men that caused them to leave the industry in droves, with the resultant closure of potentially profitable pits so that their manpower could be used to fill empty places at neighbouring pits. In 1966 a grand plan, costing £217,000 was approved that entailed driving a roadway to Bedwas Colliery with all of Wyllie’s coal brought up the Bedwas shafts. This was never implemented. Wyllie Colliery was closed by the National Coal Board on the 23rd of March 1968. The shafts were filled and capped in November 1979.

It was claimed that it was losing £15,000 per month and its coals had a high sulphur content making them difficult to sell. Out of the 645 men on books at closure 419 were transferred mainly to Windsor Colliery 135, Marine, Britannia 11, Bargoed 59, Penallta 66, Nantgarw 54, Bedwas 16, Markham 12, Celynen North 9, Oakdale 7, Celynen South 6, Waterloo 2 and one each at Cwmcarn, Llanhilleth, Six Bells and Trelewis. Attempts by Oakdale Colliery to work the remaining reserves of coal in the Wyllie take in the 1980s ended in failure.

Based on the Nine-Feet seam this colliery’s coals were classed as types 203 and 204 Coking Steam Coals, the 203 was weak to medium caking, and the 204 was medium to strong caking. Both were low volatile, low sulphur and low ash in content. They were mainly used for steam raising in boilers, for foundry and blast furnace cokes, or for coking blends.

Some Statistics:

  • 1924: Manpower: 337.
  • 1927: Manpower: 696.
  • 1928: Manpower: 971
  • 1930: Manpower: 1,248. Output: 350,000 tons.
  • 1931: Manpower: 1,237.
  • 1932: Manpower: 1,400.
  • 1933: Manpower: 996.
  • 1934: Manpower: 1,406.
  • 1935: Manpower: 961. Output: 300,000 tons.
  • 1937: Manpower: 984.
  • 1938: Manpower: 840.
  • 1940: Manpower: 855. Output: 400,000 tons.
  • 1945: Manpower: 729.
  • 1947: Manpower: 765.
  • 1948: Manpower: 749. Output: 250,000 tons.
  • 1949: Manpower: 799. Output: 194,000 tons.
  • 1950: Manpower: 799.
  • 1951: Manpower: 830. Output: 194,140 tons.
  • 1953: Manpower: 915. Output: 252,000 tons.
  • 1954: Manpower: 863. Output: 213,000 tons.
  • 1955: Manpower: 857. Output: 214,381 tons.
  • 1956: Manpower: 868. Output: 227,417 tons.
  • 1957: Manpower: 845. Output: 220,166 tons.
  • 1958: Manpower: 803. Output: 239,854 tons.
  • 1960: Manpower: 643. Output: 161,748 tons.
  • 1961: Manpower: 665. Output: 173,698 tons.
  • 1962: Manpower: 672.

This information has been provided by Ray Lawrence, from books he has written, which contain much more information, including many photographs, maps and plans. Please contact him at welshminingbooks@gmail.com for availability.

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