As usually happens on these occasions, those men still mobile after the explosion made their way from the area affected as quickly as possible. The distance to the shaft bottom was quite short and it was not long before all the burnt men arrived there. Some of them arrived clad in nothing more than boots and the remains of burnt pants and shirts. Some indeed had not been wearing shirts when the explosion occurred. One or two demanded blankets but although first-aid materials and blankets were available at a point 60 yards from the shaft on a road which had not been traversed by the men, a misunderstanding arose as to the ready availability of these materials and pressure was put on the onsetter to allow the men up the pit. Then, immediately afterwards on the surface, the burnt men had to walk from the top of the downcast shaft to the first-aid room, a distance of 80 yards.

The situation is not one on which a facile opinion can be passed. On the one hand there is the oft-repeated experience that burnt men will get as far away from the place where they have been burned as quickly as possible. It is also accepted that cases of bad burns are always serious emergencies requiring the swiftest possible transfer to the nearest point at which highly specialised treatment is available. At the same time it is most important that the victims should not be allowed to exert themselves unduly, in order not to prejudice in any respect the possibility of their ultimate recovery. No matter, then, how men escape from a district in which an explosion has occurred, I think it is desirable that immediate arrangements should be made for their rapid examination at the pit bottom, where facilities should be available for swiftly covering burns, however extensive, with sufficiently large, sterile, non-medicated dressings. At times this could best be done merely by wrapping the victim in a sheet. Hot bottles are not really needed. There should be no unnecessary delay in raising badly burnt men to the surface. Carrying is essential and should be insisted upon.

It is a pleasure to close this section of my report with a tribute to the skill of the doctors attached to and the staff of Wythenshawe Hospital. The five injured men who were transferred there were very severely burned and the fact that three of them recovered — one with burns extending over more than half his body surface, some of the burns being of the third degree — reflects great credit on the care and patience with which the injured men were treated.

Whilst the failure to detect the body of gas concerned in this explosion may be looked upon as caused by lack of imagination and the casual nature of the inspections made, the part played by the electricians is more reprehensible. Through the construction of the control switch, the main enclosure had to be dead before the front cover could be taken off; it was, therefore, safe to examine the main enclosure when the front cover had been removed. This principle could not be applied to the busbar chamber, and to make this chamber dead it was necessary to switch off at the section switch outbye. This was not done and therefore the busbar chamber was still alive when the men worked on it.

Regulation 8 (3) of the Coal and Other Mines (Mechanics and Electricians) Regulations, 1956, which, though a new Regulation, nevertheless re-enacts what has been in force since 1913 (No. 131(g) of the General Code of Regulations, 1913) states perfectly plainly that "No person shall commence any work upon any conductor, or in proximity to an exposed conductor, being in either case a conductor in a circuit in which the voltage exceeds 25, until an electrician of the mine has ensured that such conductor has been made dead and has taken any necessary steps by earthing or otherwise to ensure that it will remain dead until he is satisfied that it is safe to restore the current." The qualified electricians concerned must have known that they had not carried out this Regulation. If any further reminder as to what they should have done was needed, it was provided by the words "Warning Isolate Supply Elsewhere Before Removing Cover" which were cast on the top of the very cover they loosened and twisted around.

The isolating switch which would have made the busbar chamber dead was only 90 yards away from the place where the electricians were working.

The majority of electrical accidents occur when men work on exposed live apparatus either deliberately or accidentally and the high number of accidents indicates the prevalence of these dangerous practices. The more likely hazard, of course, is that of electrical shock, but if gas is present the risks are vastly increased, with the possible dreadful result which accrued on this occasion. There is no doubt that an improvement in the conduct of some electricians is urgently needed. There is no need to provide more Regulations — if the present ones were carried out the number of accidents would undoubtedly fall. What is required on the part of some electricians is a greater sense of responsibility. Comparatively recent legislation, by requiring electricians to have higher qualifications, should be a stimulus towards this end. Indeed any step in that direction, for instance the joining of a professional society, would be advantageous. In my opinion it is for electricians themselves, by their own efforts, to eradicate the type of conduct which led to the present disaster.

The insulation tester which was found near the control switch was not of an intrinsically safe type; such instruments should not be used in safety lamp mines where inflammable gas is likely to occur.

Until the fall on the east side face on 28th February — 1st March the ventilation in the Plodder district complied fully with the requirements of the law. The fact that from such a simple occurrence as a fall on the face there developed a chain of circumstances resulting in an explosion sufficient in extent to kill eight persons makes it necessary to study closely the full implications of the system of ventilation in vogue. After a careful consideration of all the factors involved I have come to the conclusion that the feature most to blame for the subsequent failure of the ventilation in No. 2 circuit was the practice of having two intakes to the face of the dip development district.

The practice of having two intakes extended up to a double unit face may sometimes appear attractive, since the building of an air crossing and the making of another connection to the return airway may thereby be eliminated. Furthermore, following a recommendation contained in Sir Andrew Bryan's report on the formal investigation which he held on the fire at Creswell Colliery, Derbyshire, in 1950, the practice has been recommended by the National Coal Board in certain cases, as a step designed to reduce the risks arising in the event of fires on intake airways.*

Experience, however, has shown that when two intake airways are taken to the face, difficulty may be experienced in balancing the two splits of air, one of which has often to be regulated. Difficulty may also be experienced in maintaining a constant flow of fresh air in each split since, through the normal hazards in the pit, such as falls on the face, on the roads, and the disturbances which can be caused to regulators if coal is hauled or conveyed through them, an unbalance in the two air flows can easily arise. Pressure and quantity variations are undesirable in any road but particularly so in intake airways where electricity is often in use. Furthermore, in the regulated road, the velocity of the air passing may be low, particularly near the face ripping of a large modern loading gate (closely adjacent to which may be one or more electric motors) and may become insufficient to sweep away gas from the lip which, through open breaks, may connect with gas accumulations in the wastes. A low air velocity might even be insufficient to prevent gas from a ripping lip travelling outbye against the air current.

The inherent difficulties of dealing with such a system of double intakes were seen at Chanters; for instance when, after the explosion, the instinctive step of regulating the unaffected split (No. 1) was taken in order to force more air up No. 2, gas appeared in No. 1 split in considerable quantity. It must be concluded that when this type of ventilation difficulty arises, an increase in the total quantity flowing is necessary to keep all places clear.

Another hazard, which did not arise at Chanters, but which nevertheless is a very real one, is that on the length of face between the two intakes the pressure difference is often small and the ventilation on this part of the face may be little more than stagnant. Indeed, recent work in the Division in connection with the avoidance of danger from gas in the waste, a matter dealt with in Section 56 of the Mines and Quarries Act, 1954, has shown that the inflammable fringe of the gas in the waste may be nearer to the coal face and consequently could be a greater hazard on a length of face between two intakes than in other cases where pressure differences between adjacent roads are greater. This experience confirms that found in the Division on those faces where unventilated dummy gates are in use — there is much more likelihood of gas being found in dummy gates between two intakes than where the dummy gates are on a length of face between an intake and a return.

For all these reasons I consider that the practice of having two intakes and one return for a double unit face, particularly a face where the roads are advancing on the strike and the face is on a gradient, should be regarded with suspicion. I am very much aware that the practice has been a feature of Lancashire mining for many years and that the alternative on such a face — descensional ventilation on part of the face — may sound unorthodox and unattractive, but a few successful cases of this practice have been put into operation and I recommend that the possibilities of further using this method be closely studied. Indeed I understand that some mining engineers are already looking upon the practice of descensional ventilation with more favour for other reasons. On a level face no descensional ventilation difficulties arise and the system of a middle intake and two return gates should normally be adopted as the standard and best practice.

Where, for other reasons, it is essential that dual intakes should be provided to ventilate double unit faces, a special study should be made of the ventilation in the "scale" gate and of the face between the two intakes with a view to ensuring that at all times and under all conditions the ventilation is constant and adequate; furthermore, in view of the dangers of low velocity air currents it is necessary that particularly careful examinations be made if electricity is in use and shots are fired.

Another issue which requires careful consideration is the practice of making use of adjacent mines either as the primary source of fresh air for any given mine being worked, or as the means for providing a return from the workings. It will be recalled that in his published report** on the accident at Knochshinnoch Castle Colliery on 7th September, 1950, Sir Andrew Bryan recommended that where practicable the provision of an escape roadway giving direct access to an adjacent mine should be considered. Following this recommendation, H.M. Inspectors and the National Coal Board encouraged the policy of providing connecting roads between neighbouring mines. It is essential, however, that the position and arrangement of any interconnecting roadways should be planned with great care, as otherwise proper control of the ventilation may prove to be difficult. The chief point to be criticised in this case was the decision to take the return air from Chanters Plodder district to Gibfield colliery; the use of intake air from St. George's and Bedford shafts was almost inevitable until a way had been found to induce air to flow down Chanters No. 1 shaft below the Trencherbone level. Chanters Plodder district should have been given its own return from the start; as soon as a connection to Gibfield No. 1 East level had been made, a separate connection to Chanters No. 2 pit (a connection 120 yards long was put through with considerable despatch after the explosion) should have been started. Further, to divert Chanters air to Gibfield along two roads (one of which was untravellable on account of falls which presumably could have become worse suddenly at any time), some of the air going into a return and the rest into an intake, and later to "fiddle about" with 80 yards of two feet tubing to cool Gibfield 21's Plodder district can only be described as "improvisation at its very highest". A serious weakness in planning is indicated. It might be argued "if the steps taken provided nearly 10,000 cubic feet of air in Chanters Plodder district, surely the end was achieved". There must be considered, however, particularly in ventilation practice, the dependability of any scheme, and it is on this test that interconnecting must be judged. The 21's district in Gibfield is a long way from Gibfield shafts and the differences of pressure in the district are slight. In these circumstances the amount and perhaps the direction of the ventilation flowing is apt to be disturbed by the opening and shutting of doors, the movement of tubs, etc. These factors, together with possible disturbances of a similar type near St. George's and Bedford shafts (which could arise in areas outside the responsibility of the Chanters manager) may have been the unknown factor which contributed to the drop in quantity found to be passing after the explosion. Another disadvantage of multiple interconnecting is that afterdamp, as well, incidentally, as gas and dust, may be carried into the workings of other pits, with consequences which can be well imagined. On this occasion, even before the nature of the emergency was fully clear, it was necessary to warn all men at Gibfield and St. George's to be withdrawn from the mine; and later, when, for some unexplained reason, the air flow from Bedford was reversed and traces of carbon monoxide were found in Bedford No. 3 shaft, men had to be alerted in part of that colliery also. I have come to the conclusion, therefore, that a complete ventilation survey of this complicated and interconnected system of ventilation should be made with a view to overcoming the known difficulties, such as the failure of air to flow down Chanters No. 1 shaft below the Trencherbone level, and ensuring that the ventilation provided on all faces concerned would have the primary asset of reliability.

I would like to record my sincere thanks to the representatives of all organisations who assisted in the investigation of this explosion; in particular I have to thank Mr. G. Smith, Sub-Area Surveyor of No. 2 (Wigan) Area of the National Coal Board, and his staff for much preliminary work in the preparation of the plans. Special thanks are due to the Technical Information Section of the Safety in Mines Research Establishment who prepared the outstanding pictorial drawing of the group of collieries (Plate I) and arranged the presentation of the illustrations.

I have the honour to be, my Lord,

Your Lordship's obedient servant,

G. Hoyle.