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II. PARTICULARS OF THE COLLIERY AND ITS BACKGROUND
6. The "William" Pit is one of a group of pits sunk near the coast-line adjacent to the port and town of Whitehaven in the County of Cumberland. The pits in this group were sunk to work the rich seams of under-sea coal at the southern end of the Cumberland Coalfield. The "William" is situated on a ledge between the cliffs and the sea, 49 feet above sea level and 400 yards north of Whitehaven L.M.S. Railway Station. There are two circular shafts. The downcast shaft is 12 feet in diameter and is used for the winding of men, mineral and other materials. The upcast shaft, 14 feet in diameter, is a second means of egress and is not used for winding mineral. Both shafts were sunk about the year 1806 to the Six Quarters Seam at a depth of 891 feet. Many years ago, however, the lower length of the shafts was abandoned, and winding has since been carried on from an inset 30 feet below the Main Band Seam which is intersected by the shafts at a depth of 624 feet. There is, in addition, a third means of egress, by way of a roadway connecting the workings of the "William" Pit with the adjoining Haig Pit through the Wellington Pit, shown on Plan No. 1.
7. It is well to remember that this group of pits at Whitehaven, including the "William", has had a somewhat chequered history in recent years in respect of ownership and a sombre record of disastrous explosions. In the past fifteen years ownership has changed no less than four times. In 1933 the Whitehaven Coal Company, Ltd., sold the pits to Messrs. Priestman Whitehaven Collieries, Ltd. In 1936, the pits were acquired by the Cumberland Coal Company (Whitehaven), Ltd. At this time the "William" had been standing idle for two years and was re-opened by the new Owners. With the nationalization of the coal mines, the ownership passed to the National Coal Board, and the "William" Pit became a unit in the No. 10 or Cumberland Area of the Northern Division of the Board.
8. So far as explosions are concerned, the group has probably the blackest record in the annals of coal mining. Since the advent of the present century, its record of explosions, involving the loss of ten or more lives, is as follows :–
| Persons | ||
| Date | Colliery | Killed |
| 11th May, 1910 | Wellington | 136 |
| 5th September, 1922 | Haig | 39 |
| 12th February, 1928 | Haig | 13 |
| 29th January, 1931 | Haig | 27 |
| 3rd June, 1941 | William | 12 |
| 15th August, 1947 | William | 104 |
9. Nor is that all. The "William" Pit has a considerable history of trouble from heatings and fires due to spontaneous combustion. Indeed, the explosion in 1941 occurred in connexion with a large sealed off area of workings in the Main Band Seam, which had been abandoned in 1928 and in which at some time previously there was known to exist an active fire due to spontaneous combustion. There is an extensive area of abandoned bord and pillar workings in this 10 feet thick Main Band Seam, in which, although there had been much splitting and robbing of the pillars, there had been little "broken" working. In his Report* on this explosion, the late Mr. F. H. Wynne, C.B.E., B.Sc., stated: "Having regard to the thickness of the seam and the method of working, it is perhaps not surprising to find a history of trouble from time to time due to spontaneous combustion. Definite colliery records of trouble from this cause are, however, somewhat meagre and confined to comparatively recent years." Consideration of this present explosion, in some of its aspects at least, as well as of future precautions to be taken at the colliery, cannot be divorced from this background of explosions and fires.
(b) Seams Worked and Method of Working
10. Three of the principal seams, the Bannock Band, the Main Band and the Six Quarters, have been more or less extensively worked at the "William" Pit during its long history. As might be expected, the workings in the richest of them-the Main Band-are the most extensive. This seam lies about 25 fathoms below the Bannock Band and 42 fathoms above the Six Quarters Seam and was worked by the bord and pillar method. Largely because of the liability to spontaneous combustion which gave rise to heatings and fires which had to be sealed off, the seam was abandoned many years ago. From the re-opening of the pit in 1937 until June, 1941, the output came from longwall workings in the Bannock Band, but the workings in this seam were also sealed off and abandoned at that time, following the explosion which occurred in a sealed-off area of old workings in the Main Band Seam and which seriously affected the workings in the Bannock Band. Work was then started in the Six Quarters Seam from a cross-measures drift which had previously been driven to catch this seam. Thereafter it was from the Six Quarters Seam that practically the whole of the coal output since 1941 was obtained.
11. The Six Quarters Seam has an average thickness of 2 ft. 9 in. of clean coal with a volatile matter content of approximately 37 per cent. The floor is a fairly strong fireclay, and the immediate roof consists of 2 ft. of shale overlain by a band of coal 20 in. thick. Above this lies more shale until another thin seam of coal, with a fireclay floor, is reached, about 12 ft. up. The full dip of the seam is 1 in 10 in a westerly direction. The under-sea cover in the area concerned is about 120 fathoms.
12. The first districts to be developed and worked from the Six Quarters Drift were No. 1 South and what are now called the old Nos. 1 and 2 North Districts (see Plan No. 1). They were advancing machine-cut conveyor longwall faces. Old No. 2 District finished in 1946, but coal production in old No. 1 District continued until April, 1947. The dismantling of plant and withdrawal of materials from this district had not been completed at the date of the explosion. In the meantime, in anticipation of the decline of output from these districts and also in accordance with the general development plan for the working of the Six Quarters Seam, further development work was carried on seawards in a north-westerly direction. At the date of the explosion, the lay-out and full extent of the workings completed and still in progress in this area were as shown in Plan No. 2. These workings comprised No. 1 Rise, No. 2 Rise and No. 2 Dip District, all advancing double-unit longwall machine-cut conveyor faces; the continuation of No. 3 Trunk Road known as Skelly's Heading; a Shortwall Face known as No. 1 Dip off No. 3 Trunk Road; the Back-End Shortwall Face; No. 2 Dip Heading (Allen's Drift), which had been driven in stone to connect with the seam on the inbye side of a fault; and, finally, Brannon's Heading, which was being driven in coal from No. 2 Dip Heading to connect with the return airway from No. 2 Dip Longwall. Except for No. 1 Rise District which had ceased production in January, 1947, on striking a fault, work was proceeding in all of these places at the date of the explosion. Because of faulted ground, the left face of No. 1 Rise District lagged considerably behind the right side face.
13. With the exception of No. 2 Dip Heading (Allen's Drift), in which pneumatic picks were used in coal-getting, all coal was undercut by compressed-air driven chain coal-cutting machines, the machine employed on the No. 2 Dip face being fitted for wet-cutting. The coal was transported from the faces by conveyors to a central loading point near the outbye end of No. 3 Trunk Road beyond its junction with No. 2 Dip Trunk Road. The face and inbye gate conveyors were operated by compressed-air, while the main trunk belt conveyors were electrically driven. From the central loading point the coal was taken in 10 cwt. capacity hutches by under-rope endless haulage to the shaft fully two miles outbye, by way of the main intake airway.
14. Shot-firing was practised in the coal on all faces, in the rippings or brushings and, on the No. 2 Dip face at least, also in the roof along the face opposite the wastes, in order to get stone for strip packs. The shot-holes were bored by compressed-air driven rotary drills. Permitted sheathed explosive (Polar Ajax) and sand-clay stemming were used throughout.
15. The method of roof support on roadways was mainly by steel arches, while wood props and lids were used at the actual working face. The system of support and roof control on the No. 2 Dip double-unit longwall face-the face on which the explosion started-consisted of wood props and lids at the coal face, roadside packs along the gateways and strip packs of varying widths built in the wastes and having between them varying widths of wastes, opposite which wood chocks were set.
16. The types of lamp provided for general use underground were Ceag 2.5-volt Alkaline Superlite electric cap lamps, with ordinary Protector flame safety lamps for gas detection by the workmen where required by the General Regulations, and Protector No. 6 flame safety lamps for the officials. In addition, six Nife 2.5-volt Alkaline cap lamps were in use. Fixed electric lights from the mains were also provided at the central loading point and at certain parts of the main haulage road.
17. The main ventilation was produced by a steam-driven Walker Indestructible fan placed near the top of the upcast shaft. The fan, erected in 1903, was said to be designed to pass 150,000 cub. ft. of air per minute with an 8 in. water-gauge when running at 275 revolutions per minute. An air measurement taken in the fan drift some weeks before the explosion showed that approximately 60,000 cub. ft. of air per minute was passing with the fan running at 240 revolutions per minute, with a water-gauge of 5.8 in. The general direction of the ventilation, the air splits and the quantities passing at various points as recorded in the air measurement book for the month of July, and the firedamp content of the air at several points in the circuit, as revealed by analyses of air samples taken shortly before the explosion, are shown in Plan No. 1.
18. It will be seen from Plans Nos. 1 and 2 that the intake air was split at No. 3 Junction. The air in the rise split travelled inbye along No. 3 Trunk Road and was coursed round No. 1 Dip Shortwall face, and the left and right faces of No. 2 Rise District, before passing to the return airway. The air in the second split passed part way along No. 2 Dip Trunk Road and was coursed around No. 2 Dip Face, entered the Back-End Shortwall from No. 2 Dip Heading and then passed to the main return by way of an overcast over No. 3 Trunk Road. The face of No. 2 Dip Heading (Allen's Drift) was ventilated by fresh intake air by means of two small compressed-air driven auxiliary fans placed in series inside tubing, the outer length of which passed through the three brattice doors on No. 2 Dip Trunk Road. A second air-crossing at the junction of the return from the No. 1 Dip Shortwall Face with No. 3 Trunk Road was due to be completed on the night of the explosion, with a view to providing a separate ventilation split for this face.
(e) Output and Persons Employed
19. During the three months prior to the explosion, the output of the colliery was just over 2,000 tons per week. In addition to normal coal production, a considerable amount of development and repair work was also being done at this pit. Work was organized on three shifts. Coal filling, haulage and coal winding were done on the day-shift, pan-shifting, brushing and packing, and coal cutting on the back-shift, and back brushing and general repairs on the nightshift. The normal complement of workmen on the three shifts was 177, 159 and 104 persons, respectively. On the 15th August, the day of the explosion, 166 persons had been working underground on the day-shift and 133 persons on the back-shift-the shift on which the explosion occurred. Of these back-shift workmen, however, 14 persons were on a "staggered" shift and had all ascended the shaft by 5.40 p.m. and, because of illness, another back-shift worker had also ascended by that time. This left 118 persons underground at the actual time of the explosion.
20. The mine was under the daily supervision of Mr. W. H. McAllister who, after being Under-Manager at the colliery for over 3 years, was promoted to be Manager, in November, 1946. To assist him he had one senior oversman on the day-shift, a back-shift oversman, three sectional oversmen, an official designated as a ventilation engineer, and a number of deputies and shot-firers. The Manager was supervised by a Colliery Group Agent, Mr. D. McPherson, who, in turn, came under the direction of the Area General Manager for Cumberland, Mr. J. G. Helps, and of a Deputy Production Director for the Division, Mr. J. A. Nimmo. The Agent, Mr. McPherson, had taken up his duties at the end of March, 1947, in succession to Mr. A. B. MacDonald, the former General Manager of the Cumberland Coal Co. (Whitehaven) Ltd., while Mr. Helps and Mr. Nimmo commenced their supervisory duties at the William Pit on 1st January, 1947, on the advent of Nationalization.
(g) Precautions Against Coal Dust
21. Suitable arrangements were made to meet the requirements of the General Regulations in respect of precautions against coal dust. The roadways were apportioned in numbered zones to enable systematic cleaning-up, stone-dusting and sampling to be done. Several persons were employed daily in cleaning-up dust accumulations, special attention being given to conveyor transfer and loading points. The duties of the "ventilation engineer" included the supervision of this work, the collection of the necessary samples for analysis, and the recording of the required information in the prescribed book. Contrary to the statutory requirements, dust samples were not collected during the month of July. About 3½ lb. of stone dust per ton of coal output were used underground for stone-dusting on roadways and before shot-firing. The incombustible dust used was produced from limestone obtained from quarries in Cumberland. The results of the analyses of roadway dust samples collected after the explosion and over a period of months before the explosion showed that, on the whole, stone-dusting had been satisfactory from the view-point of the standard laid down by the Regulations. So far as the coal face was concerned, the longwall coal cutter working on the face in the No. 2 Dip District was fitted for wet cutting and there was little evidence of coal dust to be seen on the face in this district.
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