The explosion occurred at 11.55 p.m. during the first and second hours of the fourth or night shift of Friday, 22nd August, 1947.

All the twenty-four persons at work in the district were involved: nineteen were found dead, and of the five recovered alive two subsequently died. None of the other 192 persons employed elsewhere in the mine at the time were affected. A full list of the casualties is given in Appendix I.

Discovery and Rescue Work. The first persons to raise the alarm and to reach the scene of the explosion were a party of three deputies, W. Younger, J. Shanley and Hy. Robinson, all trained rescue men, who were regularly employed in the adjacent fire area previously mentioned. This party usually carried a canary and flame lamp detectors, and they had with them a reviving apparatus for use in case of emergency. They had examined the fire stoppings alongside the 4th North Low Main Main Road on their way inbye from Morrison North shaft and had just reached their station in the fire area about 250 yards to the south of and beyond the offtakes for the 4th North District, when they felt a momentary cessation of the intake air, followed immediately by a rush of dust laden air coming in a normal direction from Morrison North shaft. This occurred at 11.55 p.m. according to Younger's watch. They realised fully what this denoted, and they picked up the canary and their flame lamps and ran northwards in the direction of the Morrison North shaft towards the seat of the trouble, which they soon discovered was in the 4th North District. Shanley then returned to the 4th Bankhead and telephoned this information to the surface, while Younger and Robinson entered the 4th North District, taking the canary with them. They went first into the Straight East gate through the heavy canvas cloth (which they state positively was intact), where they saw a light and heard moaning sounds ahead, and about thirty yards farther on they found one man (Minto) alive but unconscious and two others (Bailey and Talbot) apparently dead.

Robinson went back to the 4th North offtakes to telephone urgently for help and to get a stretcher for the injured man Minto, with whom Younger remained. It was then 12.20 a.m. by Younger's watch. Younger discovered that another of the men (Bailey) was alive, so he went to meet Robinson returning with the stretcher and sent him to fetch the reviving apparatus from the fire area. Robinson soon returned with Shanley and the fore-overman, John Hutchinson, who had descended Morrison North shaft at midnight and had been informed of Shanley's telephone message.

Younger and Shanley then recovered the three men in the Straight East gate, while Hutchinson and Robinson attempted to explore the South Heading, but the air was at that time too hot and thick with fumes to enable them to proceed very far. However, a little later on, and without effecting any repairs to canvas cloths, these four men were able to get along this Heading as far as the 2nd East loading point and up the 2nd East loading gate as far as the face line. The cloths across the old East gate had been disarranged and the one across the 2nd East gate had been destroyed. They came across the two drillers, Johnson and Kilgallon, both alive but unconscious at the deputies' kist, and they brought them out to fresh air.

By the time the first rescue team arrived in the district, at about 1.30 a.m., these men had also recovered deputy Estell still alive at the kist and had brought out five dead bodies from the South Heading, and they had located four bodies in the 2nd East loading gate. An attempt was also made by them to get to the loading point on the Straight East gate, where they could see signs of fire, but the fumes were too heavy for them to make any progress. They were not at that time aware there were any men on the West side, but in any event the canvas cloth across the South Heading to divert the air current into No. 1 West bord had been destroyed and this side was consequently fouled with afterdamp.

About this time the Undermanager, Mr. Peel, arrived on the scene and took charge of the operations. Rescue teams quickly located the remaining bodies on the South Heading beyond the 2nd East loading point, on the 2nd East loading gate beyond the face line, and on the West side; while another rescue team entered the Straight East gate, where they came across Westgarth, with his clothing on fire, just beyond the loading point. Other clothing there and a wood chock carrying the conveyor gearhead were smouldering. They extinguished these incipient fires with sand and brought out the body of Westgarth, after which the fumes in the gate quickly dissipated.

There were no falls of ground seriously impeding the ventilation, which was speedily restored by re-erecting the cloths across the South Heading and the 2nd East loading gate and renewing those on the old East gates, and the remaining bodies were recovered without the aid of rescue apparatus.

The exact positions of the dead and injured persons when recovered are shown on Plan No. 1.

The clothing on the nineteen bodies was examined at the surface for contraband by a Police Inspector in the presence of an Inspector of Mines and representatives of the National Coal Board and the Miners' Lodge; and cigarettes and matches, including one pocket petrol lighter, were found on eight of them. I refer to this matter later in this report.

Exploration of the District. This was possible within a few hours of the explosion, at which time the Undermanager found a small accumulation of firedamp in a roof cavity at a 3 ft. fault at the roadhead of No. 4 West bord, which he describes as four per cent. at about one foot from the roof but which was not discernible in the general body of the air. This had dispersed by the following day.

It was soon evident that coal dust had played the major part in the explosion; indeed, in view of the amount of coking and of the previous history of the seam at this colliery, it was at first thought the explosion had been one of coal dust only and that firedamp had not entered into the matter at all. Investigation showed, however, there was no evidence that any preformed cloud of dust had been created at the outset or that there had been any igniting medium of sufficient intensity to initiate a coal dust explosion.

The details of the after-effects in the district are given on Plan No. 1, and the main indications of the passage of flame and blast are described below.

On the Straight East gate there was pronounced coking on the roof supports etc. from the roadhead back down the gate as far as the North Heading return airway, where the regulator door had been blown out. Minto, one of the survivors, stated that he and his mate Westgarth had just reached the loading point, 30 yards back from the coal face, at the commencement of their shift and that they were undressing when he "heard a bang", but he cannot recollect anything more. He was found afterwards 50 yards outbye and near to two other men, Talbot and Bailey. These men had not arrived there when Minto first entered the gate with Westgarth and he cannot explain how he came to be found at this point afterwards.

There were no signs of coking along the Straight East face or along the old East face line but there were deposits of burnt dust, indicating the passage of flame, which increased progressively in amount as far as and into the old roadhead of the 2nd East gate. The only signs of force along this face line were the complete shattering of the regulator door at the Wembley connection and the displacement of roof baulks with a fall of roof about the old roadhead, through which there was still a good passageway for the air current.

The tailgate of the Straight East face was unaffected, but the old East Motor bord conveyor gate was heavily coked, especially about its centre.

On the 2nd East loading gate from the old roadhead the burnt dust deposit merged into coking up to about 20 yards inbye the 2nd East face line. From this point outbye to the South Heading there was increasingly heavy coking on the inbye side of the props, and the delivery end of the face conveyor was heavily coked. The canvas cloth across the outbye end of this gate had been destroyed and the conveyor motor gear, switches and cables had been blown across the South Heading into the mouth of No. 4 West bord opposite. The bodies of Moore, Reed and Bell (No. 1) were found alongside the gate conveyor on this road, and two of them were lying with their heads outbye as if they had been caught by a blast coming down the gate; and the body of Hodgson was found with both legs fractured beyond the 2nd East face line.

On the West side there was no sign of the passage of flame or blast in the inbye tail gate, where the bodies of Grimley, Rutherford and Birtle, face canchmen from the 2nd East side, were found; they had sustained no violence and death was due to carbon monoxide poisoning only. The first signs of coking were beyond the roof canch which Brown and Simpson were taking from No, 5 West bord towards the tail gate, and the body of Simpson was found with burning injuries farther outbye along the face line. Down No, 5 West bord there was coking on the face side of the timbers and in this gate was found the body of Brown, also with burning injuries.

In No. 4 West bord, which is opposite the 2nd East loading gate, there was coking on the east side of the timbers but no signs of violence. Outbye along the face line there was again heavy coking on the south side of the props and lighter coking along the incompleted new return airway and down No, 1 West bord almost to its junction with the South Heading. There was also considerable sooting and slight coking in the old No, 2 West bord (which had a dirt stopping at its inbye end), in which the deputies' kist was situated. Here two survivors, Johnson and Kilgallon, after having completed their shift drilling shotholes in the East gates, had been sitting for a few minutes talking to deputy Estell when they were "attacked by flame"; but neither of them can recollect anything afterwards.

On the South Heading there was very slight intermittent coking on both sides of the timbers from No, 1 to No, West bords. Three empty tubs of a set standing on the landing Opposite No. 1 West bord had been tipped over on their sides towards the east, long timbers in the mouth of No. 5 West bord had been blown out against full tubs standing on the heading and four of these tubs had been forced off the rails and partly tipped over towards the east. The body of Chapman was found here in a crouching position facing outbye, crushed between one of the displaced tubs and the side and the bodies of his two mates, Fenwick and Bell (No. 2), were found a few yards outbye along the Heading. The driller Johnson recalls having passed these men on this part of the heading when he came outbye at the end of his shift ; they had partly completed the advancing of the conveyor along the 2nd East face and it can only be conjectured what they were doing on the heading at this time. Johnson thought they were looking for timber. The bodies of Appleby and Rowland were found just outbye the 2nd East loading point and those of McKever, Roe, and Martin about 30 yards outbye; all these men were lying as if they had been knocked down by an outward blast along the Heading.

The evidence was clear that the explosion had not traversed the 2nd East face or any part of the tub gateways or roadways at the inbye end of the South Heading. On the other hand it is significant that it had swept throughout all the conveyor roadways, both existing and disused (but still accessible).

The explosion had developed remarkably little violence, doubtless due to the relatively small quantity of combustible matter in the atmosphere, coupled with the absence of long lengths of roads along which pressure could build up and to the opportunity for dispersal of the force of an explosion, both in front of and behind the flame, provided by the South Heading and the West face line; and the comparatively slow travel of the flame had evidently caused the unusually extensive coking to be observed.

It is, I think, reasonable to deduce from this evidence that a mild firedamp explosion in which coal dust played no part at first had traversed the East face line between the Straight East loading gate and the 2nd East loading gate and had extended outbye along these gates and the intermediate East Motor bord, so as to open up several separate coal dust explosions ; one in each of the gates. The most violent of these dust explosions occurred on the 2nd East loading gate and this erupted violently into the South Heading and continued up No. 4 West bord opposite to the West face line, where it spread leftwards as far as the tailgate and to the right down No, 1 West bord to the South Heading, and there died out.

The Presence of Firedamp. It is necessary at this stage to discuss how inflammable gas came to be present in dangerous quantity in the 4th North District, having regard to the previous history of the seam at the colliery.

There was subsequent evidence of the presence of firedamp on the West side in the roof cavity already mentioned; and on 27th August, five days later, Inspectors of Mines and the Undermanager found a larger accumulation at the roadhead corner of the inbye West tailgate, which tailed out some yards along the face line and down the gate. About three hours later it was found this gas had been dispersed by the normal air current, and an unsuccessful endeavour was made by short-circuiting the air to ascertain its actual point of issue.

In view of the proximity of old workings on all sides of the 4th North District any emission of gas from the Hutton Seam itself can, I consider, be ruled out; and the Low Main Seam 30 ft. above had been pillared in the area for over twenty years and any gas occluded in the strata above the Hutton Seam would have drained away during this period.

The suggestion was made by the workmen's representatives that combustible gas other than methane from the fire area in the Low Main Seam distilled by the heat inside the area now sealed, where the temperature is known to be still very high, had found its way through the strata below into the district. This was extremely unlikely and moreover, Mr. E. W. Muddiman, Chief Scientist for No. 6 Area, was able to state positively at the Inquest that the air samples collected in the West tailgate on 27th August contained no combustible gas other than methane ; which disposes of this theory.

This leaves only the strata below the Hutton Seam to be considered.

In considering possible reasons for the presence of an inflammable mixture of firedamp and air on the East face line and the Straight East gate, two important factors have to be taken into account :-

	(1) The unsatisfactory arrangement of the single cloth across the outer end of the Straight East gate, on the short length separating the intake and return air at this rather vital point.
	Any derangement of this cloth would allow intake air to short-circuit to the return and affect adversely the ventilating pressure creating circulation of air in this part of the district. Alternatively, a similar disturbance of the regulator cloth at the Wembley connection would have the same effect; and either or both of these events would considerably reduce the quantity of air coursing this part of the district and could even produce stagnation of the air.
	There was no direct evidence of any failure of the ventilating arrangements, but they were sufficiently precarious to warrant being taken into consideration for this purpose.
	(2) Disturbance of the strata below the Hutton Seam by abutment pressure brought about by the working of the lower seams, which can cause firedamp to be liberated from these seams or wastes and at the same time provide a relatively easy upward path for the gas-a not unknown occurrence at other mines in this country. There were no indications of floor breaks, apart from fault slips in the 4th North District, but it is the fact that water made in the Hutton Seam percolates through to the Towneley workings below.

In this particular area the Towneley Seam, 26 ins, thick and 55 yds. below, had been worked since 1946 and a longwall face was being advanced northwards; and the Bottom Busty Seam, 3 ft. 1 in. thick and a further yds. below, had been worked in 1931 and again in 1946. There are also two thin unworked seams between the Busty and the Towneley Seam. A section of the seams is given on Plan No. 2.

The relative positions of the workings in the Hutton Seam and those of the two lower seams in the area are shown in Plan No. 2, from which it will be seen that those in the Towneley Seam had increased the span of the worked-out area from west to east and that a face advancing to the north was widening the span from south to north. At a certain stage in this expansion of the worked-out area an increased rate of general settlement was inevitable, and accompanying this there would be increased pressure at the abutments surrounding this area. These effects would be transmitted to the Busty Seam waste below. Furthermore, it will also be seen from the same plan that there had been an abutment in the Busty Seam from 1931 to 1946, which would have the effect of further disturbing the strata.

It seems probable that such action did occur and caused firedamp to issue from these lower seams and workings, and could account for the firedamp found on the West side after the explosion. The firedamp involved in the explosion may well have issued under the same influence on the East side, particularly where the various abutment pressures meet to the north of the Wembley return airway connection.

If this action caused only a very small rate of issue of firedamp of a few cubic feet per minute, which would not be detectable on the reduced flame of a safety lamp with the normal air current flowing, any interruption in the ventilating arrangements from one or other of the possible causes mentioned above (1) would in a comparatively short period bring about a firedamp-air mixture above the lower limit of inflammability in this part of the district.

I am not unmindful of the evidence that firedamp was found afterwards at two points on the West side before the ventilation was fully restored, but having regard to the fact there was something of the order of 9,000 cu. ft. of air per minute coursing this side and the inbye East side, it would be necessary to postulate a very high rate of emission of firedamp in this part of the district to bring about an explosive mixture in the air current-a most unlikely event in the circumstances. Any disturbance of the cloth on the Straight East gate would not affect seriously the amount of air coursing this part of the district, and any similar derangement of the cloth regulator at the Wembley connection would considerably increase this quantity.

I am therefore forced to the conclusion, in the absence of any other feasible explanation of the source and presence of this inflammable mixture on the East side, that the firedamp came from the lower workings and that the locus of the emission was on that part of the East face line immediately on the return side of the Wembley connection, where the area would be above the most in tense abutment pressure zone in the Towneley Seam. The evidence of increased violence at this place indicates a richer inflammable mixture there.

The colliery records of air samples show that the Towneley Seam gives off firedamp but that it cannot be described as a gassy seam, although occasionally trouble is experienced with firedamp in the workings of this seam; the Busty Seam, on the other hand, is rather gassy.

The colliery barograph shows that for some days prior to, and at the time of, the explosion the barometer had stood at a consistently high level.