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| The Beginning. | Safety Inspections. | Lamp out. | Electric plant. | State of workings. | Rescue work. | Hartley Bank explosion. |
Edward Colliery. 1925. (5 Killed).owned by Wallsend and Hebburn Coal Co., Ltd., Northumberland Information taken from the Mines Inspectors Report. Peter Banks. Joseph Coxon. Reginald Hogg. Francis Matthews. John T. Young. The explosion occurred in the Yard Seam of the 9th. West District. Four men working with an electrically driven coal cutter. Peter Banks, Joseph Coxon, Reginald Hogg, and Francis Matthews, died from shock and burns injuries. John Young, died from carbon monoxide poisoning while travelling outbye. When the explosion occurred there were three electrically driven chain coal-cutting machines in use in the Yard Seam. The explosion occurred at No. 1 machine to the right of the 2nd. South Mother-gate. This was the last working place being served by the ventilating current; it being the furthest inbye, 650 yards from the downcast shaft. It was also the highest point in the working face. No. 1 machine was opening out a face on the rise side of a fault. The 9th. West engine plane was the intake, and the 2nd. South Mother-gate was the return. They were separated by a single brattice sheet in a short roadway, (about 8 yards long), between the main intake and main return. There was no airway through the fault to the right of No. 1 machine. Electric safety lamps were in general use at the colliery and leading machine-men carried flame safety lamps. Between 1 p.m., Saturday, 8th. August, and midnight no one was working in the mine. At midnight a shift of men, deputies, (working as coal-fillers) and other workers descended to fill off the cut coal and to prepare the face. Contents In contravention of the Coal Mines Act, 1911, safety inspections were not made before men started work. At 4 a.m. on Sunday morning, the 9th. August, an overman entered the mine to ensure that faces were clear for the machine men who were coming to cut the coal on the 6 a.m. shift. He travelled to the front of No. 1 machine, but did not make any inspection of the face to the right of the machine and towards the fault. After leaving this machine, he lost the light in his oil flame lamp between the face of the 2nd. South Mother-gate and No. 4 machine. Shortly afterwards he lost another light which he had procured, and proceeded to complete his inspection with an electric lamp. Electric lamps cannot detect gas. Men who had been at work from midnight to 6 a.m. between Nos. 1 and 4 machines, were all using electric lamps; they say they noticed nothing unusual in the atmosphere and heard no falls of roof. No unusual conditions as to roof weighting or disturbance of the ventilating system could be traced prior to the explosion. The roof in the neighbourhood of No. 1 machine was still standing a fortnight after the explosion. The 6 a.m.shift consisted of 23 miners, including three sets of machine men. Contents On the way inbye, No. 1 machine worker Joseph Coxon, told Lauder, who was going to No. 4 machine, that he had knocked out his flame lamp. No evidence existed of this lamp being re-lit. The last person to see the four machine-men alive was a driller named Mayne, who was drilling the canch in the first gateway to the left of the 2nd. South Mother-gate. About 15 to 20 minutes before the explosion Mayne went to No. 1 machine to get assistance to remove a full tub. He noticed the machine was running with the jib in its working position; Coxon was using a pick to kirve between the jib and bottom coal. Mayne's description of conditions on the face where No. 1 machine was working was; 'it was pretty warm'. After receiving assistance in removing the tub he commenced drilling. Shortly afterwards he felt a rush of hot air and dust coming from the direction of No. I machine. He made his way outbye without cutting off the air from his drill. He was later rescued in the 2nd. South Mother-gate by a machine-man named Turner. Turner was in charge of No. 2 machine, he says that at about 12 minutes to 7 o'clock he noticed a rush of air, and thought it was due to a big fall of roof; on going out to the landing he found the main separation sheet between intake and return on the 9th. West engine plane blown down and also noticed a smell of burning. He had all the switches for the coal cutter circuits opened and ran to the shaft to telephone the lamp man on the surface that "something had happened in the 9th. West district". It was now about 7.20 a.m. Investigations showed little evidence of violence or burning throughout the district; there was however, evidence of coking on timbers, and small roof falls in the Mother-gate. There was a fall on the face between the 2nd. South Mother-gate and the first left on Sunday night. Firedamp was present. This was not being cleared by the available ventilation, the machine and flexible cable were taken to the surface for examination on the following Wednesday. Contents The findings of the investigation of the electrical plant indicated the probability that the explosion was initiated by electric arcing or sparking between the current carrying parts of the plug connector, and the corresponding radiused edges of the contact tubes with which they engage to complete the electrical circuit between the machine and the trailing cable. As this electrical burning on the pins and tubes was at their outer extremities, it could only have been brought about in the act of inserting or withdrawing the plug while the circuit was otherwise complete between the source of supply and the coal cutting machine motor. In this connection it is very significant that Coxon's body was found with an India-rubber glove on the right hand and the other glove grasped in the left hand; also that undoubted signs of exactly similar burnings were found on two other trailing cable plugs examined on the surface. This points to the conclusion that the plug connector had been used to make or to break the circuit while the controlling switch on the machine was switched "on" and while the electrical pressure was on the trailing cable. Mr. C. A. Nelson, who first examined the No. 1 machine after the explosion, found the jib racked clear of the coal; the haulage rope laid out preparatory to turning the machine the plug inserted in the socket of the machine with the hinged bolts which are provided to secure the plug in position, and the controlling switch on the machine in the neutral position. Samples of dust were taken by the Inspectors of Mines after the explosion, within a 5 yard radius of each of the machines, and also samples from the roof, sides and floor over a length of 50 yards in each adjacent roadway, which showed on analysis that the combustible matter in the dust at the face was slightly over 50 per cent., but that in the roadways it was well within the required standard. The possible sources of ignition were flame safety lamps, matches, abrasive sparking of the cutter picks, and electricity. In the entire absence of other evidence the investigation of this explosion points to the conclusions that an accumulation of firedamp was ignited, probably by electrical arcing at the plug connector on No. 1 machine; that the limitations were fixed by the volume of the explosive atmosphere, and that coal dust took practically no part in the explosion. Contents In discussing this accident, it is difficult to understand how longwall workings could drift into the state shown by a glance if proper supervision had been exercised by the management. A longwall face, about 550 yards in length, on which three electrical coal-cutting machines were at work, depended for its ventilation on a single brattice sheet at the bottom of the 2nd. South Mother-gate, across a short roadway about 8 yards in length, between the main intake and return airway, along which pony putters and men were continually passing during the working day. With the open cross-cuts to the left of the Mother-gate it appears obvious that very little air would traverse the working face, and that practically none would reach the of No. 1 machine. The return airway was very tortuous and upon examination was found to be rough and in some places of very restricted cross-sectional area. With the district in this condition and in a seam that gave off firedamp, it is not difficult to account for gas accumulating in the neighbourhood of the 2nd. South Mother-gate and No. 1 machine. An air measurement taken in the ninth west engine plane five days after the explosion, showed that all the air then entering the district was 3,217 cubic ft. per minute. In the 2nd. South Mother-gate, 26 yards from the last working place, the quantity was found to be approximately 215 cubic ft. per minute, whilst at the regulator in the main return the measurement was 5,868 cubic ft. per minute. This latter measurement showed an increased volume for the seam of 74 percent over the measurement made prior to the explosion. The ventilation was increased after the accident by cutting off the air from other districts and opening the Yard Seam regulator. Even with this addition, assisted as well by compressed air, it took nearly seven hours to clear the afterdamp from the 2nd. South Mother-gate, which is only about 200 yards in length. As previously stated, no inspection of the district was made before the midnight shift commenced work. Later, the overman failed to make an inspection of the face between No. 1 machine and the fault and, indeed, it is doubtful if he made an examination for firedamp anywhere in the district. There seems little doubt that he lost his light on the two occasions previously mentioned, due to the presence of firedamp. It can be stated without hesitation that the laxity of the officials in neglecting to make proper inspections and tests for firedamp was the primary cause of the disaster. The investigation also showed that no effective use was made of the flame lamps supplied to the machine-men, who, in any case, had very vague ideas as to where to make tests for firedamp. It was generally admitted that the flame lamp was hung at the gate-end switch on arrival at the commencement of the shift, and allowed to remain there. Contents The rescue work was carried on courageously by the personal efforts of the workmen and officials and all persons who took part deserve unstinted praise. It is, however, necessary to point out that the Central Rescue Station was not notified until more than two hours after the explosion, and even after this loss of valuable time there was complete lack of direction on the part of the management, with the result that effective work by the rescue brigades did not commence at the advanced base until 11.15 a.m., nearly 4½ hours after the explosion occurred. A superior official of the mine should be appointed to take charge of the advanced base to receive reports, collect information from survivors and rescuers, and organise the rescue work, and such an official would have been invaluable in this case. It was also unfortunate that there were no trained local men available to act as guides to the rescue teams. Five rescue teams in all took part in the recovery of the bodies, and the reports of the leaders show that they were keen and accurate observers under difficult conditions, pointing to efficient training. The importance of organisation of rescue work cannot be over-emphasised. On this occasion it was about 2.30 p.m., or 7 hours and 40 minutes before the last body was brought to the base, and the loss of time would have been particularly serious if it could have been shown that the men had lived an appreciable period after the occurrence. Using the time periods actually taken by the rescue brigades on different phases of work, and assuming that the Central Rescue Station was notified half an hour after the explosion, the first body could have been brought out to the base two hours after the occurrence, and the remaining three bodies in the next hour, employing four rescue teams in the work. It should also be borne in mind that numbers of rescuers unnecessarily risked their lives, and in several cases had themselves to be rescued. Contents Attention should be drawn to the very remarkable similarity between this explosion and the explosion which occurred at Hartley Bank Colliery, Netherton, Yorkshire, on 23rd May, 1924. The report by Henry Walker, C.B.E., H.M. Chief Inspector of Mines on the Hartley Bank Colliery, Netherton, Yorkshire, contains recommendations for the prevention of accidents of this character. The Agent and Manager of the Edward pit, both admitted they had not read the report. It would therefore appear to be opportune to direct attention to that report and to the concluding general remarks in it. Proceedings were instituted against the agent and manager, alleging a large number of breaches of the Mines Act or General Regulations. The agent was fined £40 and ordered to pay £14 4s. 4d. in costs, and the manager was fined £50 and ordered to pay £14 16s. 4d. in costs.  |