VI. COMMENTS

(a) On the Examination of the Shot-hole for Breaks

59. Clause 6 (d) of the principal Explosives in Coal Mines Order requires that, before a hole is charged, the shot-firer shall examine it for breaks running along or across it. No scraper or other tool for detecting breaks was found in the vicinity of the No. 2 Dip Face and I can only conclude that, contrary to the Regulations, the shot-firer who charged and fired the fatal shot, and who lost his life in the explosion, had not examined the shot-hole for breaks. This was a grave omission. The condition of shot-hole No. 3, as examined several days after the explosion, has already been described and is illustrated in Fig. 3. Its condition then was such as would suggest that the presence of a break could readily have been detected had a proper tool been used for the purpose. Whether the condition of the shot-hole before the firing of the shot was such that a break could have been detected had the type of tool normally supplied at the colliery for detecting breaks been in fact used, is a matter for conjecture, but it does seem probable.

60. In mines where firedamp is a hazard, the examination of shot-holes for breaks seldom receives the close attention it merits, possibly in some measure due to the failure to use a properly designed and maintained break-detector. In view of the number of explosions of firedamp in recent years caused by shot-firing with permitted explosives in holes crossed by breaks, I am of the opinion that the use of a break-detector made to an approved specification and properly maintained should be made compulsory. Reference to this and other matters relevant to shot-firing practice is made later.

(b) On the Examination for Inflammable Gas Before Shot-firing

61. Clause 6 (f) (i) of the principal Explosives in Coal Mines Order requires that :–

62. In my Interim Report I pointed out that because of the words within the brackets in the above clause, it was permissible in law for a shot-firer to charge and fire a shot in close proximity to any inaccessible waste whether or not it contained or was likely to contain inflammable gas in such quantity as to be indicative of danger. I also stated that whilst I would not for one moment suggest that a shot-firer would fire a shot if he thought that shot would ignite inflammable gas, nevertheless I considered that the clause allowed too much latitude and that the statutory requirements of the firing of shots in all coal mines where inflammable gas was not unknown should be strengthened in such a way as to restrict the latitude allowed. The normal interpretation of "inaccessible" as used in Clause 6 (f) (i) is that the place cannot be examined by the shot-firer using his flame safety lamp. There is no doubt, however, that by means of, say, an aspirator attached to a thin tube or pipe, samples can be collected for examination so as to ascertain whether or not a so-called "inaccessible" waste in the immediate vicinity of a shot-hole does or does not normally contain inflammable gas in such quantity as to be indicative of danger. After all, inflammable gas in an "inaccessible" place in close proximity to a shot is no less dangerous than if it had been found in an accessible place near the shot.

(c) On the Use of Sheathed Permitted Explosives

63. Only sheathed permitted explosives were used in the shots fired on the No. 2 Dip Face on the shift in which the explosion occurred. There seems to be a view in some quarters-a view unwarranted by the facts-that the use of a permitted sheathed explosive surmounts the potential danger of ignition of inflammable gas by shot-firing. It has been known, however, for many years, that it is potentially dangerous to fire a shot in a hole which passes through a break connected with a bed-separation cavity or a waste in a gassy mine, even when permitted and sheathed explosives are used and where the general ventilation of the mine is considered good in terms of Section 29 of the Act. Nevertheless, the exact conditions necessary for ignitions in these circumstances cannot yet be defined. With a view to their determination, a series of experiments was conducted several years ago at the Laboratories of the Safety in Mines Research Board, but they proved inconclusive because of the limitations of the "Break Gallery" in which the experiments were conducted. Plans have been prepared for the provision of a new "Break Gallery" which will permit a greater range of experimental conditions. In view of the number of ignitions and explosions initiated by the firing of shots in holes associated with breaks and open partings, it is essential in the interests of safety that research on this problem should be undertaken without further delay. I recommend, therefore, that immediate steps be taken to expedite this investigation. In this connexion, bearing in mind the practical difficulty of ensuring at all times that a shot-hole is not associated with breaks or partings, and other matters relevant to this explosion, I cannot do better than quote, in full, Safety Circular No. 137, issued on the 24th October, 1945, by my predecessor, Sir John R. Felton. It was addressed to the Owners and Managers of all Mines under the Coal Mines Act, 1911, and the Secretaries of National and Local Associations of Owners, Officials and Workmen. It reads :–

(d) On the Storage, Use and Handling of Explosives, and Shot-Firing Practice in General

64. It was clear from the evidence of various witnesses in regard to such matters as (i) lack of agreement between the records of explosives and detonators issued from and returned to the surface store and the records of explosives and detonators issued to and used by shot-firers and deputies underground; (ii) the finding of cartridges of explosives underground in places other than in secure cases or canisters; (iii) the finding of detonators in places other than suitable and securely locked cases or boxes; (iv) the finding of sheathing removed from cartridges; (v) the siting of shot-holes; (vi) the record of the number of shots fired by a deputy with statutory duties to perform; (vii) the apparent failure of a shot-firer to comply with certain requirements of the Explosives in Coal Mines Order before firing a shot; and (viii) the high quantity of explosive used per ton of coal got; that the whole business of storage, use and handling of explosives and shot-firing practice in general was not given enough care and attention.

65. It was disclosed, for example, that on the day-shift preceding the shift on which the explosion occurred, the No. 2 Dip Face deputy had fired forty-two shots in addition to performing his statutory duties. Plainly his statutory duties, or his shot-firing duties, or perhaps both, could only have been carried out in a very perfunctory manner. It was also disclosed that the position and number of shot-holes required were left too much to the discretion of the holeborer. Although a shot-firer need not charge every shot-hole, and certainly ought not to charge and fire a shot in a hole that is not properly placed, nevertheless it is a sore temptation to him to make use of all shot-holes that are drilled.

66. This whole business of the use and handling of explosives, and all operations connected therewith, is of vital importance to the safe working of a colliery. It is essential for the management, therefore, not only to see that an efficient system governing all phases is laid down, but also that the necessary supervision is given to see that it is properly carried out. As so often happens, what is the business of everybody becomes in the end the business of nobody. I suggest, therefore, that at all collieries where explosives are used, a thorough investigation should be made into this matter with the object of devising the most efficient system appropriate to the circumstances; and that, thereafter, a superior and responsible official of the mine should be given the direct responsibility of seeing that the approved system is efficiently applied and operated in practice on all three shifts. In my Interim Report I also recommended that it should be made a statutory requirement that the maximum number of shots which it is permissible for shot-firers and deputies, respectively, to fire, should be fixed for each district of the mine after a trial made under working conditions, both in respect of the number of shots per statutory shift and per hour during the shift, the trials to have regard, in the case of a deputy, to his primary responsibility to carry out his statutory duties and, in the case of both shot-firers and deputies, to any additional duties which may be assigned to them, and any assistance given to them.

(e) On the Practice of Firing Roof Shots on Longwall Faces to Obtain Packing Material

67. As already explained, this explosion originated with the firing of a shot in a hole drilled at an angle into the roof on a long-wall face and directed towards the waste behind and immediately contiguous to the face. The purpose of this shot, and of several others fired that night on the No. 2 Dip Face, was to obtain packing material to extend the strip packs in the waste. Such shots are variously known as "cuckoos", "uppers" or "upper-cuts". The practice of firing them is (or was) common in several collieries in different parts of the country. Since, by definition, the practice applies only to shots fired at or near the edges of wastes on longwall faces, it is a practice fraught with grave risk and danger in many mines. It will not be denied that in a mine where firedamp is not unknown, a waste behind a longwall face is a place where inflammable gas is most likely to be found and is, morever, a place which cannot be examined for the presence of inflammable gas in the normal way by a deputy or shot-firer using his flame safety lamp. Further, the roof at or near the edge of a waste is just the place where breaks and bed-separation cavities are extremely prevalent and most liable to occur. This combination of dangerous factors, inflammable gas in conj unction with breaks or cavities, clearly indicates that the practice of firing "cuckoo" shots should be avoided like the plague.

68. In evidence, the Manager not only stated that he was unaware that "cuckoo" shots were being fired but that he had given instructions that such shots were not to be fired. Either these instructions had not been clearly given or understood, or the supervision was insufficient to see that his instructions were properly carried out. The fact remains that "cuckoo" shots were fired and that the firing of one of them originated the explosion. Nevertheless, the Manager did not regard the practice as a dangerous one, provided, as he said, "it was properly carried out". As I have already made plain, I regard the practice as one which should be prohibited in mines where firedamp is a hazard. In my Interim Report I suggested that, until the present statutory requirements in relation to shot-firing had been suitably amended or extended in all coal mines where there was firing of "cuckoo" shots in close proximity to wastes containing or likely to contain inflammable gas in such quantities as to be indicative of danger, the management should consider immediately the taking of one or other or all of the following steps

69. I am satisfied that much can be done by the application of efficient roof control measures to eliminate entirely the necessity for firing "cuckoo" shots. After all, there are whole areas in the country where this practice is unnecessary even where roof beds are equally as hard as those in areas where the practice exists. Strong straight rows of supports applied along the edges of wastes and well-built packs of good quality, suitably dimensioned and spaced, would in most, if not all, cases concentrate force sufficient to cause the roof to break down in the wastes. Moreover, effective roof control measures may do much to control and even reduce the rate of emission of firedamp at or near working faces and also prevent the formation of open breaks which often contain inflammable gas. Such breaks often communicate with and provide paths for draining off accumulations of firedamp in bed-separation cavities and wastes, or for the leakage of the air necessary to produce an inflammable mixture in such places. Further, with effective roof control there would be less tendency for the formation of bed-separation cavities, for the sudden issue or migration of accumulations of gas from the waste into the roadways and working faces, due to excessive weighting and heavy falls in wastes, and for uncontrolled leakage of air to places where such leakage may be dangerous. Indeed, quite apart from its probable beneficial effect on production, I can think of no other matter likely to pay greater dividends in relation to safety in mines generally than proper attention to roof control.

70. Since adequate ventilation is the first and by far the most important defence against explosions of inflammable gas, it was not surprising that many questions at the Inquiry were directed towards establishing whether or not the ventilation was adequate at the time of the explosion. Although it was clearly established, as will be evident from the air measurements recorded on Plan No. 1, that there was a considerable drop in the quantity of air reaching the working faces in the Six-Quarters Seam as compared with the quantity passing in both the main intake and return airways near the shafts, nevertheless there was no evidence to support any view that the quantity reaching the working faces was insufficient to ensure adequate ventilation under normal conditions. This conclusion was supported by the few instances where small percentages of inflammable gas were detected and recorded by the deputies and also by the results of analyses of air samples. It was also clear, however, that the ventilation was capable of improvement by a further reduction of leakage, by some re-arrangement of the inbye air-circuits and by enlargement of certain airways. and, indeed, work towards effecting improvements in all of these was in actual progress at the time.

71. The trouble in this explosion was that the inflammable gas had collected in a part of the mine, namely the goaf or waste behind the No. 2 Dip Face, and bed-separation cavities associated with that waste, where the gas was out of direct contact with the general ventilation. Consequently, any increase in the quantity of air passing along the No. 2 Dip Face would not have materially changed the condition or lessened the potential danger from this accumulation of inflammable gas. A reservoir of inflammable gas anywhere in a mine is always a potential source of danger; but it becomes a lively hazard if it is near, or may react upon, a working place, or near any possible source of ignition. And in these circumstances it is clear that the more the gas accumulation is out of the direct path or sweep of the general air current, the more difficult does it become to take effective steps to guard against the danger from it by means of direct ventilation. In all coal mines where inflammable gas is not unknown it is therefore incumbent upon all responsible for the management to see that, quite apart from any other steps they may take to overcome the potential danger, all ignition hazards are eliminated in proximity to wastes unless it is known that the wastes are free from dangerous accumulations of inflammable gas.

(g) On the High Death Roll

72. It will be seen from Appendix III, prepared by Dr. A. Roberts, H.M. Mines Medical Officer for the Northern Region, that forty-five of the victims whose bodies were found on the inbye-side of the air-crossing on No. 3 Trunk Road, died of carbon monoxide poisoning. None of these bodies showed any sign of burning and only one showed any mark of physical violence-a fractured skull, probably sustained after the occurrence of the explosion. These victims had all been employed in that part of the workings comprising Skelly's Heading, No.2 Rise District and No. 1 Dip off No. 3 Trunk Road. It is clear that these men had not been in an area traversed by flame or subject to serious violence, that they must have survived the actual explosion, that they had travelled some distance after the event before they were subsequently overcome by the deadly afterdamp of the explosion, and that they had a more or less equal chance of survival to the three survivors, Birkett, Hinde and Weighman, who were employed in the same area of the mine.

73. While it was unfortunate that none of these forty-five men went back with the three survivors, nevertheless it is probable that if these men, some of whom must certainly have known that an explosion had occurred and who had some opportunity to determine their course of action, had been provided with a ready means of protection against carbon monoxide, the death roll might well have been reduced. It is seldom that the oxygen content of the afterdamp of an explosion is so low as to be unable to support life. Largely because of stone-dusting and more effective ventilation systems, it is a feature of most explosions in recent years that they are less violent and are confined to smaller areas of the pit than were the explosions of earlier years, but that, due to the higher concentration of men demanded by modern mining, the death roll per unit of area covered is larger than formerly. Nevertheless, a high proportion of the deaths is still due to carbon monoxide poisoning. Following the considerable research during recent war years into means of protection against poisonous gases, it may be well worth while reconsidering the design of self-rescue respirators, with a view to providing miners with a more suitable form of protection against an atmosphere containing sufficient oxygen to support life but contaminated by carbon monoxide-such as often occurs in the after-damp of an explosion-and thus enabling the wearer to reach a place of safety.

(h) On the Operation and Organisation of the Trained Rescue Brigades

74. As might be expected in such large-scale operations as took place on this occasion, where things had to be done and arranged with the least possible delay, it was not surprising that a careful review of all that happened revealed a few weaknesses in the organisation. My object in directing attention to this matter is not for the purpose of suggesting that blame attached to anyone-for all gave of their very best and their conduct was most praiseworthy-but with a view to effecting improvements in the organisation in future. Two weaknesses were the failure to observe the need at an earlier stage in the operations (i) for additional Proto Apparatus and instructors trained in its use, with the result that the staff of the local Brigham Rescue Station was overworked and the fresh air base was not at all times under the supervision of a man of instructor status ; and (ii) for a rest for some of the members of the teams whose efficiency was beginning to be affected by overwork. Further, the accommodation available for the large number of rescue men and for the handling of the necessary equipment was inadequate. One small room was provided for the "Proto" and one for the "Liquid Air" apparatus. This was certainly a fair share of the total available accommodation at the colliery for all purposes, but the desirability of providing temporary erections, such as tents or prefabricated structures, is well worthy of consideration at such times.

75. Another weakness was the use of two different types of self-contained breathing apparatus. It so happens that the Brigham Rescue Station, in common with the majority of Central Rescue Stations in this country, is equipped with "Proto" apparatus using compressed oxygen, whereas the Durham and Northumberland Stations, which supplied many teams, are equipped with "Liquid Air" apparatus. The use of these two different types of apparatus was undoubtedly a complication. From the points of view of supervision, standardization, efficiency and interchangeability, it is eminently desirable that all Central Rescue Stations in a Division should be equipped with the same type of apparatus. Experience gained in this disaster also shows the need for the management at every colliery to be provided beforehand with a detailed plan of operations for dealing with any serious emergency that may arise at the colliery.

(i) On the Need to take Special Measures to Safeguard Against Explosions and Fires in the Whitehaven Group of Collieries

76. In the light of this explosion and of previous disasters in the collieries immediately in and around Whitehaven, it is clear that this part of the Cumberland Coalfield presents abnormal difficulties and special problems, and that additional precautions are called for if the dangers of underground explosions and fires are to be surmounted.

77. There are several adverse factors which affect the safe working of collieries in this area where coal has been worked for at least two centuries. The collieries are relatively gassy, dry and dusty; there are extensive areas of goaf or waste in many of the seams; there are several areas sealed off because of previous underground fires; the pits are very "one-sided" because most of the districts are working under-sea coal; many of the working districts are a long distance inbye from the shafts there are still large areas of distant under-sea coal to be worked; and there is a history of underground fires due to the liability of some of the seams to spontaneous combustion.

78. These adverse factors call for (i) a high standard of ventilation; (ii) adequate dust prevention and suppression measures; (iii) the elimination as far as practicable of all possible sources of ignition ; (iv) continuous and close supervision by responsible officials of all operations on all shifts; and (v) the maintenance of a high standard of discipline. Whilst the need for all of these is well appreciated by the managements, I am satisfied that there is still room for improvement in respect of each of them. History shows that the standards which must be maintained in these matters in the Whitehaven pits need to be well above the average. In regard to item (iv), for some months prior to the explosion there was no under-manager at William Pit, due to the difficulty of securing a suitable man for the post. But in respect of each Whitehaven pit, not only should there be an under-manager, there should also be a responsible official in charge of the mine on shifts when neither the manager nor the under-manager is on duty, who should exercise the responsibilities of, and be not less qualified than, an under-manager.

79. There is no doubt whatever that the adverse factors just enumerated also make the ventilation problem at the Whitehaven pits especially difficult. They call for the provision of sufficient, well-maintained airways of ample dimensions; the elimination of all unnecessary resistance to the passage of air through the airways; the judicious splitting of the air current and the careful balancing of air splits; comfortable air velocities and reasonable pressures; close and constant watch on all development work to ensure not only that efficient and adequate ventilation is provided in the development work, but also to see that the balance between the various splits is properly maintained; the elimination of all unnecessary leakage and control of any leakages considered necessary; a very high standard of practice in relation to the construction and maintenance of doors, sheets, stoppings, etc., because of the high ventilation pressure necessitated by long airways; and last, but not least, the provision of efficient means to ensure the circulation of an adequate volume of air throughout the workings. Accurate information on most of these factors requires regular ventilation surveys for quality, quantity and pressure. Here again, although the necessity for all of these things is also appreciated and a high standard is maintained in respect of some of these items, nevertheless I feel sure there is room for further improvement in regard to most of them.

80. In my view the whole problem is so important, complex and difficult that it cannot properly be left solely to the mining engineers and managers responsible for day to day coal production. I am of the opinion that it requires the full-time services of a mining engineer, highly qualified in the science and practice of mine ventilation, who has also an intimate knowledge of explosion and fire hazards, particularly in the Whitehaven area. I suggest this specialist engineer should be employed not only for the major planning and continuous development of the system of ventilation but also that he should have a direct responsibility along with the management at each colliery for seeing that the plans are properly carried out, and that any tendency to deviate from them is immediately checked and corrected. It should also be part of the responsibility of the specialist engineer, as well as of the management, to see that all practicable steps are taken to eliminate or safeguard against all possible explosion or fire risks. And he should be allotted sufficient assistance to enable him to carry out his duties efficiently. A prime essential to the successful working of the under-sea coalfield of Cumberland, and a major problem to be solved if success is to be assured, is the provision and maintenance of adequate ventilation, for upon this depend the amount of output, the type of machinery and the system of mechanisation that can be adopted and, above all, the health and safety of the persons employed. No doubt the lessons to be learned from past experience at Whitehaven have been carefully noted by those now engaged in the planning of new ventures to work the remaining under-sea coal in this coalfield.