1. In compliance with your direction, I have held a Formal Investigation under the provisions of Section 83 of the Coal Mines Act, 1911, and under the Ministry of Fuel and Power Act, 1945, into the causes of, and circumstances attending, the explosion at Ingham Colliery, Thornhill, Yorkshire, on the 9th September, 1947, causing the loss of 12 lives and injuries to one person. I have now the honor to submit my report.

2. By kind permission of the Mayor and Corporation of Dewsbury, the Inquiry was held in the Council Chamber of the Town Hall, Dewsbury, from the 11th to the 14th November, inclusive, and I desire to record my appreciation of their assistance in placing such suitable accommodation at my disposal.

3. The appearances at the Inquiry were as follows

(a) Ministry of Fuel and Power

Mr. I-I. J. Humphrys, H.M. Divisional Inspector of Mines.

Mr. E. S. Rees, H.M. District Inspector of Mines.

Mr. G. M. Harvey, H.M. Electrical Inspector of Mines.

Dr. H. F. Coward, Director of Safety in Mines Research and Testing Branch.

(b) National Coal Board

Mr. J. Hunter, Production Director, North Eastern Division.

Mr. C. H. M. Glover, Legal Adviser, North Eastern Division.

Mr. H. M. Hudspeth, Deputy Production Director, North Eastern Division.

Mr. J. A. Hall, President, Yorkshire Area.

Mr. J. H. Scargill, Secretary, Thornhill Branch.

(d) British Association of Colliery Management

Mr. A. S. Furniss, Solicitor.

(e) National Association of Colliery Managers

Mr. A. Holdsworth, President, Yorkshire Branch.

(f) Yorkshire Deputies Association

Mr. J. Howard.

4. A list of the 25 witnesses examined during the course of the Inquiry is ~i in Appendix I, and a list of the persons killed and injured in the explosion

is given in Appendix II.

II.- GENERAL INFORMATION

5. lngham Colliery is situated within the boundaries and on the south side of the County Borough of Dewsbury in West Yorkshire, and has been producing coal since about 1860. It is connected underground to Combs Colliery and there is also a surface connection by a tramway along which the coal produced at Combs is hauled to the screening plant at Ingham. Part of the underground venti1ation system is common to both mines. Despite their surface and underground connections and the partly common system of ventilation, Ingham and Combs arc worked as separate mines, being divided by properly delineated boundaries, under Section 25 of the Coal Mines Act, 1911.

6. At Ihgham Colliery there are two coal winding shafts, the No. I downcast,

13 feet in diameter, and the No. 2 up cast, 14 feet in diameter. Both shafts were sunk to the Black Bed Seam at a depth of 277 yards, and each has an inset ~at 138 yards in the beeston Seam. An output of 180 tons from the Black Bed and Blocking Bed Seams was wound daily from the Black Bed level in No. I shall, and an output of 450 tons from the Beeston and Wheatley Lime Seams was wound daily from the Beeston Seam inset in the No. 2 shaft, giving a total daily output for the colliery of 630 tons, 80 per cent, of which went to the coke ovens., The Wheatley Lime Seam has been worked for the past 85 years so that its characteristics were well known. It yields a coal for coking and industrial use.

7. At Combs Colliery the downcast shaft is 11 feet in diameter and is sunk to the Black Bed Seam at a depth of 369 yards. The daily output from this shaft IS about 140 tons per day. From an inset in this shaft in the Beeston Seam at a depth of 224 yards, a road driven iii the seam forms the intake for the No. 2 South District, Wheatley Lime Seam, Ingham Colliery-the district in which the explosion occurred. There is also a pumping shaft at Combs, 12 feet 6 inches n diameter, sunk to the New Hards Seam, at a depth of 106 yards, from which there is a connection to a staple pit sunk to the Blocking Bed Seam. These water pits are not used in connection with the working of the mine, apart from

drainage purposes.

8. The ventilation was produced by a steam-driven Walker fan, 7 feet in diameter, situated on the surface at the lngham up cast shaft, and passing

140,000 cubic feet of air per minute at a water gauge of 3.6 inches. Safety

lamps were used throughout. The types of lamp provided for general under ground use were Ceag 2-volt electric cap lamps an(l Ceag 4-volt electric hand lamps.~ For gas testing, the workmen were issued with Davis-Kirkby flame safety lamps, magnetically locked, and the officials used the Prestwich type No. 6 flame safety lamps, fitted with internal relighters and' lead rivet locks. To meet the requirements of the General Regulations in respect of precautions against coal dust, and to facilitate systematic cleaning-up, stone-dusting and sampling, the roadways were apportioned in numbered zones. Gypsum dust was used for stone dusting throughout the colliery. The amount used was a little over 20 lb. per ton of coal output.

9. The Agent and Manager of lngham Colliery was Mr. E. E. Cleaver. The Under-manager for the No. I Pit was Mr. C. Walshaw, and for No. 2 Pit, Mr. B.

Aston. Mr. Cleaver was also agent for Combs Colliery, which had a separate manager but no under-manager. There were no overmen at either colliery, the deputies coming directly under the under-manager. Mr. Cleaver came under the -direction of the Area General Manager, Mr. j. Scoular who, in turn, came under Mr. H. M. Hudspeth, the Deputy Production Director and Mr.. J. Hunter, production Director for the North Eastern Division of the National Coal Board.

10. It is perhaps proper to recall that there is a history of firedamp in this area for, in the year 1893, an explosion of firedamp occurred at the bottom of the Combs downcast shaft, by which 139 persons lost their lives. The shaft was I hen sunk only to the Blocking Bed Coal at a depth of 165 yards; but the seam being worked at the time was the Wheatley Lime, which was entered from an inset 34 yards higher up the shaft across which a wooden staging had been fixed, leaving a four-foot space at one side for the passage of air down to the Blocking Bed seam. Safety lamps were used throughout, except in the immediate vicinity of the shaft where six open paraffin lamps were used to illuminate the shaft inset. A joint report on this disaster was made by the late Mr. F. N. Wardell, H.M. District inspector and the late Sir Henry Hall, who concluded that firedamp accumulated below the staging and communicated with a feeder of Firedamp behind the brick shaft walling. The gas was ignited by one of the open paraffin lamps. The explosion was mild and not extensive. The heavy death toll resulted from suffocation by smoke from the wooden fittings in the shaft and the wooden staging at the Wheatley Lime seam inset, which had been set on fire by the explosion. The shaft passed through a fault and an attempt had previously been made to pipe the gas made there to light the inset. Gas had, however, been ignited at this point some months before the explosion.

11. The area of coal in the Wheatley Lime Seam in which the present explosion occurred was opened out some years ago from two stone drifts driven from the Beeston Seam, through a 40 yards downthrow fault. One drift was driven at an inclination of 1 in 7 in line with, and as a continuation of, the evison Board in the Beeston Seam, and this roadway was used as a return airway, travelling and haulage road to the workings in the Wheatley Lime Seam. The other drift, which was used as the intake airway, was driven at an inclination of 1 in 2. The extent of the workings in this area from that time until the explosion is shown in Plan No. 2.

12. The seam is 2 ft. 11 ins, thick and the immediate roof is a strong bind with well-defined bedding planes. The floor is a hard fireclay. The only district working at the time was the No. 2 South. The method of working was advancing longwall with gates at each extremity of the face, which served as the intake and return airways. Three dummy gates were also driven to provide material to pack the waste. The face at the tune of the explosion was 140 yards in length. The coal was undercut by longwall coal cutters to a depth of 4 ft. 6 ins, and was loaded on to a face conveyor which discharged to a conveyor in the return gate known as South 2 Conveyor Gate. Belt conveyers in tandem in this gate delivered the coal to a conveyor on the main haulage road which discharged the coal into tubs at a loading point near the lop of the I in 7 drift. From this point the coal was hauled to the No. 2 upcast shaft in tubs of 4 1/2 and 6 1/2 cwt. capacity by an endless-rope haulage running at 1 1/2 miles per hour. The first 1500 yards of this haulage road was the Evison board, including the 1 in 7 drift. Then, 500 yards from the shaft the haulage passed round a right—angle bend into the South Ending, where it received coal coming from time South districts in the Beeston Seam. thus the haulage and conveyor roads were all in the return airway, which was also the travelling road into the No. 2 South District. The deputies’ meeting station (see Plan No. 2) was near the top of the 1 in 7 drift and was also in the return airway. Throughout the district, the conditions generally were slightly damp and water collected at certain parts and had to be pumped outbye. Electricity was used for operating coal-cutters, conveyers, pumps, drills for coal and stone, signalling system and for the telephone circuit, which extended almost In to working face.

13. As previously indicated, the intake air to the No. 2 South District came [rein the Combs shaft by way of a roadway in the Beeston Seam. This roadway,although small in parts was, nevertheless, well regulated. The intake air then passed up the 1 in 2 drift parallel to the 1 in 7 return drift through the 40-yard fault and thus entered the Wheatley Lime Seam. A statutory air measurement taken at the top of the intake drift on 26th August, 1947, a fortnight before the explosion, showed 15,500 cubic feet of air per minute to be entering the district. Other air measurements, however, showed that of this quantity only 5,950 cubic feet reached the face of No. 2 South, so that leakages—which occurred mainly at three points—were very heavy and will be referred to later in more detail.

14. On the 5th June, 1947, the No. 2 South Face was 185 yards in length. At that time the right hand side of the face extended 30 yards beyond the No. 2 South Conveyor Gate to a fault (which was being stripped at that time). The left side of the face extended for a shorter distance beyond the intake airway tail gate. In this 30 yards of face between the No. 2 South Conveyor Gate and the fault, a subsidiary tail gate was packed 9 yards from the fault side. On the 5th June, 1947, when the third and last of a series of ripping shots was being fired in this subsidiary tail gate, firedamp was ignited in a break which crossed the shot-hole and the flame passed 64 yards back along the side of the fault. In consequence, the face was shortened in order to concentrate and improve the ventilation, and a 9-inch brick wall, with a two-yard dirt pack on the outside of it, was built in the crossgate to seal off the subsidiary tail gate. The ignition of gas was investigated at the time by H.M. Inspectors of Mines and Officers of the Safety in Mines Research and Testing Branch. Following the present explosion, which blew the 9-inch brick stopping and the two-yard pack inwards towards the fault, the locality was again inspected by the same investigators to see if the previous ignition of gas had any bearing on the present explosion, but it was considered that there was no connection between the two events.

111.—THE EXPLOSION AND EVENTS LEADING UP TO IT

15. The explosion occurred in the No. 2 South District of the Wheatley Lime Seam on Tuesday, 9th September, 1947, at 11.15 p.m. during the first hour of the night shift. The number of persons normally employed during the 24 hours in this district was 105 but, owing to a wages dispute, the No. 2 South Face had not been filled off since the previous Friday and, in consequence, the normal sequence of work was interrupted.

16. On the day shift of the 9th September, men other than the usual colliers were employed filling coal off the face and boring shot-holes in the coal as the filling proceeded. At the end of the shift, however, there were 30 to 40 yards of face still to fill off. Other workmen were employed in enlarging the intake airway near to, and on the outbye side of, the Gledhill Crossgate (see Plan No. 2), and one man was attending the pump in the intake tail gate. Apart from a broken belt, which was repaired, in the outbye conveyor in the South 2 Conveyor Gate, the shift was uneventful.

17. On the afternoon shift, five men were at work erecting bars at the face of the South 2 Conveyor Gate and one man was again attending the pump. Seven others were engaged enlarging the intake at a point near Old North 2 District. The deputy on this shift said he made tests with his flame safety lamp for firedamp at numerous points in the district but found none. He ascended the shaft at 10.30 p.m. with the five men who had been working in the South 2 Conveyor Gate, leaving the district, so far as he knew, ill perfectly normal condition and certainly not anticipating danger of any kind, let alone the disaster which was to follow so soon afterwards. The remainder of the men on the shift had left the mine about an hour before the deputy.

18. The night-shift for the South 2 District consisted of 13 persons, 12 of whom perished in the explosion. The one survivor, Jesse Clarke, a shot-firer, was discharged from hospital on 5th November, 1947, apparently fit and unharmed, apart from the scars of burns, but unfortunately suffering from a loss of memory and quite unable to remember anything of the events of the tragic night. Had he been able to recall what happened, he would have been a most valuable witness and would undoubtedly have shed light on many points which arose at the Inquiry when various witnesses were endeavoring to explain the course of events that night.

19. The night-shift deputy, F. W. Pearson, two shot-firers, Bernard Hewitt and Jesse Clarke, and two beltmen, Arthur Wilson and Clifford Howarth, descended the mine at 10 p.m. This was half-an-hour before the normal time for the descent of the night-shift proper. At 10.5 p.m., before proceeding inbye, Pearson consulted with his opposite number on the afternoon shift. About 10.15 p.m. workmen on the afternoon shift, while on their way outbye from the No. 2 South District, met Pearson and his men at the outbye end of the Evison Board on their way inbye to work. The bellmen, Wilson and Howarth, had been instructed to run the conveyor belts and, after the explosion, their bodies were found in the position they would have occupied had they been performing this task. The switch in the switch-box controlling the conveyor motor was found in the “on” position but a pilot switch alongside one of the dead men was in the “off’~ position. It is possible that the men may have had time to open the pilot switch. On the other hand, the conveyor may not have been started up. What exactly happened will never be known, but, in my opinion, the question is not material.

20. The dead bodies of deputy Pearson and shot-firer Hewitt, and the unconscious Clarke, were found after the explosion at the deputies’ meeting station near the top of the return drift. The time required to walk from the shaft bottom to the meeting station was 25 to 30 minutes so that these three officials may have arrived there about 10.30 or 10.35 p.m. Their movements after arrival are a matter of deduction and to some extent of surmise. It is unfortunate that this is so, since these movements are vital to the correct explanation of what happened on the night of this explosion. It is known, however, that deputy Pearson telephoned from the meeting station to the night onsetter, Herbert Collomosse, in the shaft bottom at a time which Collomosse put at 10.50 p.m. It was an inquiry as to the number of persons on the regular night-shift, which descended the shaft at 10.30 p.m., and who were coming to work in the No. 2 South District in the Wheatley Lime Seam. The conversation, however, extended to general topics and did not conclude until 11.5 p.m. Collomosse said Pearson sounded very cheery and certainly not like a man who had any thought of impending danger. Immediately after his talk with Pearson, Collomosse received a telephone call from a deputy in another district who also inquired about the number of night-shift men likely to proceed to his district. This conversation finished about 11.10 p.m.

21. What followed soon after that is best described in the words Collomosse used at the Inquiry. “Well, at 11.15 p.m., there was a thud. That was the time it happened as far as I can say. I went out of the office and looked round the pit bottom, and I could see there was something unusual had happened. There were clouds of smoke and things coming into the pit bottom which should not have been.” After unsuccessfully trying to get into communication with the inbye districts, he then telephoned to the surface to raise the alarm.

22. Four night-shift byeworkers were travelling the South Ending when the explosion occurred. They had reached a point about 350 yards from the upcast

shaft, where two doors led into an intake airway along which they customarily

travelled to their work in the Beeston Seam. One of these byeworkers in giving evidence at the Inquiry said he saw “ a terrible flash” and heard a report, and he was thrown a distance of 5 or 6 yards. He described how the air became so thick with smoke and dust that he could not see his hand before him as he stood upright. It was very hot but it was clearer and cooler near the floor. After that, he and his mates pulled themselves together and assisted each other through the doors into the intake where the air seemed to be stagnant but quite clear. They then travelled outbye along the intake and through the separation doors to No. 2 Shaft. A deputy, who was at West Board 3 in the Beeston Seam intake 480 yards inbye from the junction of the Evison Board with the South Ending, said that at the time of the explosion he noticed a “swell of dust” which blew open separation doors between the intake and return. This deputy also stated that he parted from deputy Pearson and his two shot-firers at the junction of the Evison Board at 10.15 p.m., as they proceeded on their respective ways, thus establishing the time when Pearson and his mates left the junction of the Evison Board with the South Ending.

23. The night-shift proper for No. 2 South District in the Wheatley Lime Seam descended the shaft about 10.30 p.m. and consisted of eight persons. They were still on their way inbye and were travelling up the 1 in 7 Drift, but had not reached the meeting station, when the explosion occurred. They met its full violence and were all instantly killed by it. This brought the toll of the explosion to twelve killed and one injured.

IV.—EXPLORATION, RESCUE AND RECOVERY OPERATIONS

24. Mr. B. Aston, Under-Manager of No. 2 Pit, arrived at the colliery about

11.45 p.m. on the night of the explosion and was told by the Manager that smoke was coming from the fan drift. He descended the No. 1 downcast shaft and saw a number of workmen, from districts other than the No. 2 South in the Wheatley Lime Seam, congregated in the office near the bottom of the upcast shaft. He withdrew them into the intake, which he then proceeded to explore with a small party of deputies and workmen. On arriving at the separation doors about 350 yards inbye from the pit bottom, they found both doors damaged, the one nearest to the return airway being the most seriously damaged. They temporarily repaired one of the doors and then proceeded along the intake to the separation doors near the outbye end of the Evison Board. They found these doors completely blown out and considerable smoke and fumes issuing from the Evison Board. Realising that the explosion had occurred in the No. 2 South District of the Wheatley Lime Seam, the Under-Manager saw at once that exploration of the district at that time by way of the Evison Board was impossible. He returned to the shaft and ascended to report the position to the Manager, leaving instructions with the deputies to erect brattice sheets in the connection between the intake and return at the outbye end of the Evison Board.

25. After consultation, it was decided to explore by way of the intake airway to the district from the Combs shaft, and at 1.40 a.m, on the 10th September, Mr. Aston, accompanied by Mr. 11. Keeton, Assistant Superintendent of the Wakefield Rescue Station and a Rescue Brigade, descended Combs shaft and reached the stricken district by way of the intake airway. Although apparently undamaged by the explosion, this intake airway was not a good travelling way because of low height, rough floor, and the steepness of the 1 in 2 intake drift. On reaching the slit between the intake and return just beyond the intake drift, they found the two separation doors and their frames completely blown out in a direction away from the return airway. In traveling through the slit they thought they heard a moan and on going forward they found Jesse Clarke, the shot-firer, in the return haulage and traveling road with his head resting on the full-side rope (the side remote from the intake) which was elevated a little from the floor. It was then about 2.10 a.m., or about three hours after the explosion. The reason for Clarke’s survival has probably an important bearing on the cause of the explosion and will be more fully discussed later in this Report. The Rescue Brigade coupled up and brought Clarke out into the intake, where he received first-aid and was kept warm. They went back again and in the slit beyond the haulage road at the meeting station from which deputy Pearson had conducted his last telephone conversation, and within a few yards of the position where Clarke was found, they recovered the bodies of Pearson and the shot-firer, Hewitt. Mr. Keeton then returned to the surface for first-aid material, blankets, brattice cloth and to summon further assistance, including another Rescue Brigade, as there was no means of telephonic communication available. He returned to the fresh air base at the top of the intake drift about 3 p.m. To restore the normal ventilation circuit, brattice sheets were then erected in the slit already mentioned between intake and return and in the next slit further inbye, where the stoppings had been blown out. The party then explored further inbye along the intake to the inbye end of the Evison Board and then back along the Board to the junction of South 2 Conveyor Gate, where they found the dead bodies of the beltmen, Wilson and Howarth. They found the doors and brattice sheets erected in the continuation of the Evison Board beyond the junction with the South 2 Conveyor Gate had also been blown out and in an inbye direction. Meantime, the sole survivor, Clarke, had been wrapped up and transported to the surface and thence to the hospital.

26. In continuance of the work of restoring the normal ventilation, a start was made to erect sheets in the Evison Board beyond the junction with South 2 Conveyor Gate. While this was in progress Mr. Keeton went outbye to obtain still more assistance. At the second inbye slit, he met a party consisting of Mr. H. J. Humphrys, I-l.M. Divisional Inspector of Mines, Mr. I. G. E. Leek, H.M. District Inspector and Rescue Apparatus Testing Officer, Mr. H. M. Hudspeth, Deputy Production Director, and Dr. H. L. Willett, Head of the Safety and Research Department of the North Eastern Division of the National Coal Board. This party had descended the Combs shaft at 6.15 a.m. and had reached the district by way of the intake airway. On passing through the second slit to the Evison Board they detected a trace of firedamp, rising to about 3 per cent, at the entrance to the old road opposite and on the far side of the Evison Bord. They also detected about 3 per cent. firedamp at the outbye end of South 2 Conveyor Gate. They returned to the intake, and at a point on this roadway about 30 yards inbye of South 3 they encountered a fall which blocked their way, although a small quantity of air was passing through. It was then about 7.30 a.m. The Under-manager was left at this fall with instruction to get a traveling road made through it and the party returned to the outbye end of South 2 Conveyor Gate, where the firedamp content gradually diminished to 1 per cent, as the quantity of air passing increased. About this time Mr. J. Hunter, Production Director, Mr. W, E. Jones, Secretary of the Yorkshire Area of the National Union of Mineworkers, and Mr. Cleaver, the Colliery Agent and Manager, arrived. After consultation, an exploration of South 2 Conveyor Gate was undertaken by a party, some of whom were not wearing rescue apparatus although, as it turned out—despite the fact that the canary carried by Dr. Willett was not affected—the percentage of carbon monoxide in the air proved to be harmful, for several members of the party suffered slightly from carbon monoxide poisoning and the party was forced to retire. Their exertion, and hence their breathing, must have been heavy, due to the roadway being badly obstructed by falls several feet in height.

27. In the meantime, another party, under the charge of Mr. J. G. Bond, Deputy Area General Manager, and accompanied, by Mr. M. McCarthy, H.M. Assistant Inspector of Mines, and two rescue brigades under the charge of Mr. ‘‘. C. Riley, Superintendent of the Brierley Rescue Station, commenced an exploration of the Evison Board from the outbye end. They descended the No. 1 downcast shaft at Ingham Colliery at 9.45 a.m. on the 10th September, and travelled inbye by way of the intake airway until they reached the recently erected sheets which replaced the separation doors destroyed by the explosion at the outbye end of the Evison Board. On passing through the sheets into the Evison Board, they were unable to detect firedamp, and the canary carried by the party was not affected. On travelling up the Evison Board they found the dead bodies of five men near the bottom of the 1 in 7 drift which was heavily fallen. They were unable to find the bodies of the other three victims, which were recovered later in the day farther up the drift under heavy falls which almost blocked the entire roadway near the top of the drift. Rescue Station Superintendent Riley, after working in the drift for three hours without rescue apparatus, felt giddy and had heart palpitation, although the canary beside him showed no signs of being affected.

28. With the restoration of the ventilation and travelling conditions in the affected area, careful examination was made of the district by experts on behalf of the Ministry of Fuel and Power, the National Coal Board and the National Union of Mineworkers. Careful notes were made of conditions as found following the explosion and are shown in some detail on Plan No. 1. I, personally, made an underground inspection of the scene of the disaster, accompanied by representatives of H.M. Inspectorate, the National Coal Board and the National Union of Mineworkers.

29. Dr. F. V. Tideswell of the Safety in Mines Research and Testing Branch of the Ministry of Fuel and Power made a particularly careful survey of the area affected by the explosion and examined a large number of specimens collected by himself and others for indications of burning. Where appropriate, the specimens were also subjected to chemical analysis or other examinations. As a result, positive signs of burning were observed at a point on Evison Board haulage road, 200 yards from the outbye end, and thence inbye along the road to its junction with South 3 disused conveyor road, a distance of about 1,500 yards; on South 2 Conveyor Gate to the face, a distance of 600 yards; on South 2 longwall face, 120 yards; along the left intake tail gate, 350 yards; on Gledhill Crossgate, 140 yards; along the intake between Gledhill Crossgate and Evison Bord; and along the intake airway outbye the Evison Board to a point about 100 yards short of the right-hand gate of North 1 District. He also found signs of burning in parts of the disused districts between South 2 Conveyor Gate and Evison Board. He considered that these signs of burning indicated that the flame of the explosion traversed a distance of over 3,000 yards. In his view the explosion developed moderate violence on South 2 Conveyor Gate where there were heavy falls of ground and damage to the conveyors, and on the Evison Board where there were heavy falls on the 1 in 7 Drift, and tubs were badly damaged. Elsewhere the explosion was mild in character and the damage was not great.

V.—CAUSE OF THE EXPLOSION

30. All the expert witnesses to the Inquiry were of the opinion, and I agree, that the explosion started as a substantial explosion of firedamp. Two questions arise. What was the source of ignition ? How did there come to be an accumulation of firedamp ? I will deal with these two questions separately.

(a) Source of Ignition

31. During the course of the Inquiry only one possible source of ignition was put forward. It was the Prestwich type 6 flame safety lamp No. 9, fitted with an internal relighter and locked with a lead rivet. This lamp was issued to Bernard Hewitt, the shot-firer, before he descended the shaft at 10 p.m. on the night of the explosion. After the explosion, the lamp was found in two parts. The oil vessel, an opened pocket knife, and two portions of a lead rivet were found close to the telephone at the meeting station where Hewitt’s body was found. The top of the lamp was found on the haulage road close to where the body of Deputy Pearson was found. Both parts of the lamp, the two parts of the lead rivet and the open knife were within 5 or 6 yards of Hewitt’s body.

32. The lamp, lead rivet and knife, as found, were submitted to Mr. C. B. Platt, Superintending Testing Officer for the Ministry of Fuel and Power, and

he submitted a report to the Inquiry with the following conclusions

(1) There is as factual evidence

(a) The lamp was received in two parts and unlocked.

(b) The lamp frame passed flame when the relighter was operated in air containing firedamp. ............(Note Under cross-examination the witness said no adjustment was made to the relighter .............before the test.)

(c) Owing to the design of the lamp, the spirit vessel could not be removed from the lamp ............without extinguishing the lamp flame in the process.

(d) The screw threads between the lamp frame and the spirit vessel were in good condition ............and free from damage by force.

(e) The spirit vessel could not be replaced on the lamp frame in the condition of receipt, ............as the wick tube was bent.

(f) The wick tube could not have been bent whilst the spirit vessel was assembled on the ............lamp.

(g) The dust in and which completely filled the grooves of the screw threads of the spirit ............vessel contained traces of coked particles of coal dust this dust could not have ............accumulated in the screw threads to ‘the extent observed if the vessel had been ............assembled on the frame prior to and during the explosion.

(2) As circumstantial evidence, there is

(h) The presence of an open jack-knife which was stated to have been found near the lamp.

(i) The remains of a lead rivet also stated to have been found in the vicinity of the lamp.

The conclusions to be drawn from the evidence are that :-

(i) The spirit vessel must, of necessity, have been removed from the lamp frame prior to ............the explosion and that it was removed by unscrewing it and not by force.

(ii) The lamp would have ignited firedamp if the relighter were operated in an inflammable ............atmosphere whilst the spirit vessel was removed from the lamp frame for, in a test, the ............spark of the relighter ignited the firedamp and flame passed through the wick tube ............sleeve into the outer atmosphere.

(iii) The fact that an open jack-knife and the remains of a lead rivet were found near the ............lamp is significant but the tests to establish that the knife had been used to cut the ............rivet were inconclusive, nor could it be established that the lead rivet was, in fact, ............the rivet with which the lamp was presumably locked when it was issued for use.

33. All the other lamps, flame and electric, in use in the district were carefully examined. Two only were damaged but as they were found in places where it was considered the damage was the result of the explosion, they were not considered to be possible sources of ignitions.

34. The electric plant came under suspicion in the early stages of the examination of the district since it was known that current was on the cables when the explosion occurred and at least one switch-box was damaged. The telephone system extended almost to the face along the South 2 Conveyor Gate and the possibility that it might have been in use when the explosion occurred was considered, although the inner length of the telephone system was controlled by a switch which was probably open at the time.

35. Mr. R. L. Parker, H.M. Assistant Electrical Inspector of Mines, said in evidence that, in conjunction with officials of the National Coal Board, he had spent 26 days in the inspection and testing of the electrical apparatus in the area traversed by the explosion. There were 130 items of electrical equipment in use in the district, all of which had been examin&1 underground and most of which were later brought to the surface for further special and exhaustive test. Further, the telephones and signalling apparatus from the district were tested and reported upon by the appropriate officers of the Ministry’s Safety in Mines Research and Testing Branch. The conclusion reached was that the electrical equipment, including telephones and signalling apparatus, was very well installed and maintained and that it had played no part whatever in originating the explosion.

36. Other possible sources of ignition were examined, and, in particular, reports were made by specialist officers of the Ministry’s Safety in Mines Research and Testing Branch on the possibilities of ignition by (i) the flame of the June ignition which might possibly have continued to burn feebly at a feeder coming into a roof break or cavity and (ii) the friction of falling rock at the coal face or elsewhere. As the opinions expressed in the reports were negative, no evidence was called in respect of them.

37. Having carefully considered the evidence, and being satisfied that all other sources of ignition could be eliminated, I have no hesitation in finding that the source of ignition was the operation of the relighting device of flame safety lamp No. 9, after the lamp had been taken apart, probably because the relighter was not working properly and needed adjustment. To open a safety lamp anywhere underground at this colliery, and especially in the return airway, was a grave misdemeanor and a serious contravention of Section 34 (1) (iii) of the Coal Mines Act, 1911, as amended by S.R. and 0. 1927, No. 1155. There is, however, no evidence to show who opened the lamp or who then operated the relighter.

(b) Accumulation of Firedamp

38. There were among the witnesses two conflicting schools of thought as to how there came to be in the workings an accumulation of firedamp at explosive point. The evidence is wholly circumstantial, but before I examine this in detail it is important that it should be realized that any explanation to be true must be consistent with the following facts

(i) The accumulation of gas was large.

(ii) It was brought about quickly, certainly in less than an hour, and most likely in about ............half an hour.

(iii) It was present at explosive point in the general body of the air current of the order ............of 15,000 cubic feet per minute, passing the meeting station when the relighter of the ............open flame lamp was operated there and started the explosion.

39. There was no suggestion at all that the seam was liable to outbursts of flredamp and no evidence of any such disturbance of the strata, e.g. in the wastes, as might have forced any large body of firedamp suddenly into the air current. The only considerable body of firedamp known to exist in the whole of the area concerned was a large accumulation in the Old North I District (see Plan. No. 2), which finished in December 1945. The one school of thought associated the explosion with this accumulation of firedamp: the other school with firedamp not known before the explosion but suspected afterwards to have bled off very freely from the fault which formed the boundary of the South 2 District on the right-hand side up to the time of the ignition of firedamp which occurred there in June, 1947. I am in general agreement with the first school of thought and shall now examine the evidence and give my considered reasons.

(c) Accumulation of Firedamp in Old North 1 District

40. This old district was situated alongside the intake airway as it entered the Wheatley Lime Seam and was entered by two roadways branching off at right angles from the intake. When the district was at work, air was caused to circulate in it by two doors erected in the main intake airway between the two roads. With the doors closed, the air passed up the left-hand road round the face and down the right-hand road, after which it ventilated the other workings inbye. It was, therefore, what is sometimes called “shunt ventilation”

—a system which has serious disadvantages. It would have been far more satisfactory if an air-crossing had been built and the district separately and continuously ventilated. After the Old North 1 was finished, the door frames and settings remained in position in the intake airway, but the doors were lifted off their hinges and placed against the side of the airway, one immediately inbye each of the door frames. .

41. After the explosion, the outbye door was found in the position just indicated but the inbye door was broken into many pieces scattered along the road inbye of the door frame. Photographs of the broken door were produced at the Inquiry and also of the door frame and setting. The sill of the door frame was made in three sections. Two of these were found turned over in an inbye direction, obviously by the fracture of the door, for a section of the broken door exactly corresponded in width with the two turned over sections of the sill. Moreover, the hanging post of the door frame was broken in half, and a piece of the door was found attached to the hook on each half of the door post.

42. Mr. E. S. Rees, H.M. District Inspector of Mines, expressed the opinion that the firedamp which caused the explosion was forced out of old North 1 District by the closing of the inbye door in the intake airway between the two roads. He considered the door was closed on the night-shift within 30 to 35 minutes of the occurrence of the explosion. Dr. Tideswell of the Ministry’s Safety in Mines Research Branch held the same view, except that he considered the door was only partly closed. Both considered that the inbye door was hanging in the intake airway when the explosion occurred and that it was broken into the condition in which it was found by the blast of the explosion.

43. A good deal of evidence, much of it contradictory, negative, inconclusive and unsatisfactory was given about these doors. The management admitted that for a few months after North 1 District was stopped in 1945, the doors were used from time to time to force air round the district whilst plant and materials were being withdrawn from it, but they disclaimed any knowledge of their subsequent use. Following the removal of the plant and materials, they said the doors were lifted off their hinges and were placed against the side of the intake airway and that they remained there month after month, apparently not being required for use elsewhere. So far as is known, the last living persons to travel the intake airway past the doors, before the explosion, was the party of backshift workmen who had been engaged in the enlargement of the intake airway near the Old North 2 District. They passed the position of the doors about 9 p.m. on their way outbye at the end of their shift. Two were called as witnesses. Strangely enough, they both said quite positively that they did not see any doors at this point, either standing at the side of the airway or hanging on posts.