The colliery was the property of Messrs. Vivian and Sons who had worked it for forty years. It employed about three hundred men and boys underground and had a daily output of about 460 tons. Mr. Thomas Gray, mining and civil engineer, was the resident manager and agent. Mr. William Barras, the undermanager, John Morris, the overman, Richard Maddox, the overman and there were two fireman on the day shift, two on the night shift and Thomas Barras, the son of the undermanager, acted as assistant undermanager.
There were two shafts 297 yards apart. One of these was called the Grange pit, sunk to 410 yards and passing through all the seams from the North Fawr to the Cribbwr Fach which was the lowest workable seam, and was used for winding and pumping, and there was also the downcast shaft. The Nine feet Seam was passed at 226 yards and the Cribbwr at 306 yards. The other was to the rise and called the Albert pit and was used exclusively as an upcast shaft and was sunk to the Cribbwr at a depth of 193 yards passing through the Nine Feet Seam at 127 yards. The size of the Grange pit varied from 10 feet by 8 feet with a minimum of 9 feet 1 inch by 8 feet. The upcast also varied and the smallest diameter of 8 feet.
In descending order the seams that were worked were the Four Feet, the Nine Feet, the Cribbwr and the Cribbwr Fach. Two months before the explosion, the Four Feet was discontinued on account of numerous faults having been encountered after about nine acres had been worked by the longwall method. In the Cribbwr Fach vein, two headings had been driven 350 yards to a fault on the west side were being re-opened. The Nine Feet and the Cribbwr veins were being worked at the time of the disaster. These two seams had originally been worked to the rise of the upcast shaft towards the outcrop which was under the sea but for many years the workings in both seams had been confined to the dip of the downcast shaft and approached by cross measure drifts from the same level at a depth of 400 yards from the surface. The Nine Feet had been worked farthest to the dip so that all the workings in the Cribbwr vein were below those in the Nine Feet vein.
The explosion and its results, so far as loss of life was concerned, were confined to the Cribbwr Seam workings and the drift leading from the downcast shaft to both seams. The cross measure drift referred to was the main road into the Cribbwr seam and started at a point about 20 yards to the east of the downcast shaft and was driven in a north easterly direction for 210 yards where it reached the seam. The first 63 yards were level and the remainder dipped at a rate of about 1 in 5. From this point the main road was continued in the seam in the same distance for 230 yards dipping at 1 in 4.2. From there it went due north for a further 435 yards dipping at 1 in 5. The road was called the engine plane and had reached a point 875 yards from the downcast shaft. The coal was worked on the pillar and stall method by driving headings level from the engine plane and stalls from these to the rise until they reached the heading above, forming pillars which were left to be worked later. The pillars to the east of the engine plane had been worked back and finished at about 90 yards from the engine plane above No.8. The last pillar was being worked back and finished to within about 90 yards down No.5 heading about 495 yards from the shaft. Below this point there were five headings at work in the uppermost of these, No.6 pillar was being worked about 200 yards in. In the next No. 6 ½, the pillar working was about 200 yards in. In No.7 the workings were 893 yards from the engine plane also taking out pillars. Nos. 8 and 8 ½ were headings that were advancing through solid coal and were 825 and 809 yards in respectively. Another heading had also been started at a point 57 yards below No. 8 ½. This headings, ‘Eley’s Heading’, had been driven 25 yards in, but was not working on the day of the explosion. The main road to the dip, a continuation of the engine plane, was also being extended.
The headings were about 9 feet wide and 8 feet high, which was the thickness of the seam, with the exception of Nos. 8 and 8 ½ which were 10 to 20 yards wide for 528 yards with the lower side being stowed with rubbish and stones for 7 to 9 yards. The stalls were from 9 to 12 feet wide, according to the condition of the roof, the first being only 6 feet wide. These were also 8 feet high and were driven to the full rise at distances varying from 30 to 40 yards at about 1 in 4.
In working the pillars, the usual practice was to drive a ‘jerkin’ through the middle of the pillar to the rise and then to drive ‘lifts’, 9 to 12 feet wide, right and left, beginning at the top end and working downwards. The roof was supported by double timbers over the roadways and props set singly at the sides until the lift was finished after which the timber was withdrawn and the roof allowed to fall, forming a goaf behind.
The Cribbwr Vein was a bituminous coal with the roof made of 15 feet of dark argillaceous shale, 9 inches of band sandstone and 8 feet of argillaceous shale and iron stone. The Cribbwr Vein itself was composed of 7 feet 6 inches of coal, a parting and another 6 inches of coal and the floor was 2 feet 3 inches of fireclay, 3 inches of black shale, 2 feet of fireclay and 10 feet of argillaceous shale and iron stone.
The ventilation was produced by a Waddle fan, 40 feet in diameter at the top of the upcast shaft, which ran at 50 to 53 r.p.m. and was well maintained. It produced a total current of about 80,000 cubic feet per minute at a water gauge of 2.5 inches. There were 30,000 cubic feet going to the Cribbwr workings where 100 persons were usually employed during the day shift. A much smaller number were employed at night with a few colliers working the leading places and labourers doing repair work.
The ventilating current to seam passed down the engine plane to No. 8 ½ west heading, where it was split, about 5,000 cubic feet passing down to ventilate the main dip, Eley’s Heading, and the workings on the east side of the engine plane and returned by an air course on that side. About 20,000 cubic feet of air passed to the west by the No. 8 ½ heading, ventilating workings in heading, passing up to those in No.8 heading and from there to No.7 heading, returning to a point within 90 yards of engine plane. from their passed up to No. 6 ½ and then to No.6, entering a separate return near No.5 abandoned heading and from there to a point where it was joined by east split and finally by the Nine Feet and Four Feet return currents into the main return direct to upcast shaft.
The main dip below No.9 west level had no separate return airway and was not bratticed or provided with any means of effective ventilation. An attempt had been made to ventilate Eley’s Heading by a hand fan fixed at the entrance and air pipes leading from the fan to the face. The method had been adopted as no difficulty had been experienced in the ventilation of the main dip even though this had no return for 27 yards. The main dip, dipping one in five, was in line with the intake current. The current was taken into the face of each heading and stall to the rise by canvas brattice and in the stalls the brattice was kept within 5 or 6 yards of the face. Canvas doors on the headings were hung at the entrance to each stall. There were double doors made of wood, on each of the headings from No.6 to No.8 west and at the doors on No.8 west a considerable leakage of air was allowed in order to ventilate that heading and three stalls which were at work on the put half of it. This leakage air joined the main current after it had ventilated Nos. 8 and No. 8 ½ and some stalls to the rise of No.8, 233 yards from the No.8 face. A total of 329 yards were bratticed taking air to 15 places and there were 25 places occupied by colliers with 10 places at the side of the air course or stalls that turned away to places drive to the dip where brattice was not deemed necessary.
The seams were all deemed fiery but the Nine Feet had a reputation of being the most fiery. In the Cribbwr Vein, firedamp had not been found frequently either as accumulations or flowing from blowers. Some accumulations had been found, mainly in the stalls where the brattice had broken down or from a fall of roof. Since the beginning of the year four such cases had been encountered and these were reported. They were on 14th January in T. Miles’ place, on the 16th January in W. Rigby’s stall, on the 22nd January in W. Vanstone’s stall and on 24th February in Thomas Hopkin’s stall. The amounts were small in each case and had been cleared when the brattice was repaired. The only other place where gas had been reported was in Eley’s heading, in the place ventilated by the hand fan. Gas was reported there on the 21st February and on the 6th and 7th of March.
In February the place was about 15 yards in and gas was found by the night fireman, James Nettle while he was making his inspections. The gas extended about 3 yards back on the rise side, 1 yard across and 6 to 7 inches deep. The hand fan was put to work and the gas removed the following day. The place continued to work until the 6th Mar, when gas was again found by two colliers who had been appointed by the workmen under the 38th General Rule. It was found that the air pipes had become disconnected but when they were adjusted, the gas cleared and the place started to work again after it had been fenced off. The hand fan was kept working except on Saturday night, Sunday and Sunday night. It was working on the day of the explosion and the ventilation of the whole colliery seemed to be satisfactory.
The working places were generally dry and dust accumulated in parts of the headings. In some places the roadway was damp and in some places, wet. The engine plane was rather damp and the flow and a small quantity of water ran down it. In places to the dip of the lowest headings, water was encountered and at the date of the explosion, it was pumped by compressed air from the place parallel to the main deep, and from two other places by hand pumps. A feeder of water from the abandoned rise workings found its way to the dip, passing Nos. 7 and 8 headings and it reached No. 8 ½ not far from the face. This water made the floor of the No.7 heading wet or damp of the inbye half of its length and Nos. 8 and 8 ½ headings, damp for about 140 yards, beginning about 70 yards from the face.
The trams were called box-trams and were not loaded above the top and little dust was blown from the tubs as they were slowly drawn up the engine plane, certainly less than in other collieries in South Wales. There was dust which was cleared from the roadways with the rubbish from time to time and some part of the heading was cleared every night. There was no attempt to water the roadways and they were dry and dusty. Blasting was not generally allowed in the colliery as the manager was against shot firing and it had not been used for coal getting for a great number of years. In driving the Nos. 8 and 8 ½ headings, the coal was found to be much harder than usual and about the 30th January, permission was given by the manager to fire shots in these headings and the stalls driven from them into the hard coal. Before this, the colliers were paid more for working the hard coal and the permission to use shots was given reluctantly. There was seldom any need for shot firing in the stone work and the last occasion that this was used was in No.7 heading in 1886 when it was crossing a fault. Shot firing was thus restricted to a very limited area in the Cribbwr Seam where three or four shots had been fired in each of three places each week for about six weeks. The explosive used was gunpowder supplied to the colliers by the Company for which the colliers were not charged. It was made up into charges before it was taken down the mine and the only persons authorised to fire shots were the overman and the fireman in the Cribbwr Seam.
Open lights were permitted at the bottom of the downcast shaft and on the landing between the shaft and the top of the engine plane and at ‘stations’ appointed under General Rule 4. The station for the Cribbwr Seam was at the No.8 stage on the main engine plane and intake airway.
With these exceptions, the colliery was worked exclusively by safety lamps. The firemen used Hepplewhite-Gray lamps, a modified lamp invented by the manager and selected by the Royal Commission on Accidents in Mines as one of the four recommended lamps to replace the Davy and Clanny lamps. Everyone else used a Marsaut type lamp with only one gauze instead of two. They were bonneted and locked by a lead plug.
The depth of the lower workings of the Cribbwr vein varied from 490 yards at No.6 heading to 530 yards at the No. 8 ½ heading and the pressure was considerable which damaged the roadways and air courses which required continual repairing and enlarging which made a great amount of debris. This was stowed in two headings between Nos. 7 and 8 which were not numbered and which had been stowed for the greater part of their lengths.
The inspectors, Mr. Gray, Robson and Randall had inspected the colliery at different times and the methods used at the colliery and the procedures were well known to the Inspectors but until the explosion occurred, Mr. Robson was not aware that there was blasting in the Cribbwr vein.
The explosion occurred at 12.30 p.m. on Monday, 10th March and was distinctly heard at the surface and the immediate neighbourhood. The manager was in the office and he and all employed at the surface saw a cloud of smoke and dust rising from the mouth of the downcast shaft at a height of about 20 feet. The fan was working and the manager and five men got a cage ready and went down the downcast shaft with the object of repairing any damage that had been caused. They found that only two guides were broken near the bottom and they soon got the cages to work to bring up the men as soon as possible.
Out of the nine people who had been at the bottom of the shaft, or within 60 yards of it, four were found dead or dying. One hitcher was found fast among the woodwork in the shaft bottom, another hitcher was slightly injured, an old man slightly burned and two escaped unscathed. In the course of two hours every man and boy, about 150 in all, who had been in the Nine Feet Seam, were safely got out.
It was apparent from the first, that the explosion had happened in the Cribbwr workings, the engine plane was blocked by falls while in the Nine Feet nothing had been seen except for some afterdamp on the main dip which was carried in by the fresh air immediately after the explosion.
Mr. Robson received a telegram from Mr. Gray at 3.30 p.m. and he arrived at the colliery about 5 o’clock and went down immediately. Every possible effort was made to clear the large falls so that they could be bypassed and penetrate the workings. During the same night three men and a boy, who were making their way over the falls on the engine plane were found and brought to safety, uninjured.
One of the explorers, Daniel Brownsil, who went down soon after the explosion, ventured too far into the return airway where it was heavily charged with afterdamp and it was not until the following morning that he was rescued and brought to the surface. The medical staff did what they could but he never rallied and died on Tuesday evening. Two other explorers who had been with the same party had near escapes.
On Tuesday morning another man, John Francis, who was in the Cribbwr Seam when the explosion occurred was rescued from No 6 ½ west. He was accompanied by three men and a boy named Olds, who were recovered alive from their working places in No.7 west as far as the return airway but were affected by the afterdamp and could not reach the engine plane and creep over the falls and so had been left in the belief that they would succumb. These five were the only ones that were recovered alive from the Cribbwr workings.
On Tuesday a fire was discovered in a stall to the rise of the No.6 heading. This was extinguished with great difficulty on Wednesday evening. A second fire was found by Mr. Gray, the manager and others on Saturday evening. This was in a position 1,200 yards from the shaft where it could not easily be dealt with without exposing everyone in the pit to great danger. After a consultation with the owners, the manager decided to flood the dip workings to a point between the Nos. 7 and 8 west headings. This was done during the week and all other operations were suspended.
No one was allowed to descend the shaft for nine days as another explosion might have occurred at any moment. When operations commenced, ten horses which had been in the Nine Feet Seam were brought out. They had been without food for ten days. The water which was sent flood the lower workings had reached the stables in the drift approaching the Nine Feet and this water had kept them alive and well. Frequent visits and inspections were made, day and night and the work of exploration went on until 15th March when every part of the workings had been examined.