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November, 1952

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The disaster which occurred at Easington colliery in May of last year and which resulted in the loss of 83 lives is now the subject of a report* by Mr. H. C. W. Roberts, M.B.E., M.C., H.M. Chief Inspector of Mines. The explosion spread through 16,000 yards of roadway and was initiated by a firedamp ignition caused by cutter picks striking against iron pyrites in the Duckbill district of the Five Quarter seam. which was being worked on the retreating system, the wastes being caved. Including three stone bands totalling 13 in., this seam is 6 ft. 2 in. thick and lies at a depth of 1,050 ft. below the surface. As the debris which fell from the immediate roof was insufficient to form an arresting support it seems pretty clear that the beam strength of the higher beds caused heavy pressures to be exerted on the abutments forming the limits of the retreating face at the sides and on the unworked coal ahead of the face. The origin of the firedamp in sufficient quantity to sustain an explosion appears to be a matter of doubt, but the extra pressure on the seam would naturally tend to increase the rate of emission and, of course, there would be no ventilation across the waste because of the solid side, and it is reasonable to suppose that a considerable fall in the goaf would cause a surge of gas to be thrown on the face with disconcerting suddenness.

The erratic nature of the falls which occurred before the accident suggests that the nature of the roof strata did not favour caving and this circumstance combined with a system of multiple fans that was in use to ventilate the district, gave rise to the conditions in which an ignition was possible. Mr. Roberts is emphatic that caving should not be attempted unless the nature of the roof and the method of edge support favour falls that are both regular in incidence and carried to a sufficient height to relieve the pressure on the adjacent coal, and he also condemns the use of multiple fans wherever there is a possibility of inducing recirculation, or of not providing adequate ventilation for all other working places. He also considers that the emission of firedamp from the wastes of retreating faces should be investigated with a view to devising means of drawing off dangerous accumulations.

Pending further investigations he recommends that wherever coalcutters are in use, or are going to be used, a survey should be made with the object of selecting a cutting horizon which is as clear as practicable from any material likely to cause sparks when abraded by a cutter pick. Having regard to both the dust and sparking dangers, he asserts that the avoidance of dry cutting should be adopted as a general policy. In pursuing this point, he advocates that all possible should be done to prevent the formation of dust and to suppress, as close to the place of origin as is practicable, any dust that may be formed. He would also recommend water infusion to be investigated with a view to extending its applicability to working coal, and he suggests that a Committee should be appointed to determine the limits to which roadway conveyors may be safely employed.

An alarming feature of the report is the extent to which the explosion was sustained or aggravated by coal dust, as the routine sampling indicated that a large majority of the samples contained more than 75 per cent, of inert matter. This percentage, well within the limits of the statutory requirements and hitherto regarded as safe, suggests that something more is required and Mr. Roberts calls attention to barriers. Research should be directed, he adds, to the development of improved types of dust and water barriers, with a recommendation that shelf type barriers should, in the meantime, be adopted on conveyor roads. The rate of dust deposition should also be determined and colliery managements should call in the aid of the scientific staff in organising their sampling and dust distributing techniques. Optical methods of assessment are recommended for eliminating the time lag between sampling and analysis.

The most controversial recommendation brought forward by Mr. Roberts concerns a quickened tempo for the development of those types of coal getting and loading machines which are operated by slow moving forces. Not all seams, however, have been proved to be workable by ploughs — at least with the types at present available — and the time taken to evolve improved types with more catholic abilities will necessarily be long and the results subject to much uncertainty. The central' principle of all accidents of this kind, it would seem to us, rests with the ventilation and admittedly the ventilation of the Duckbill district at Easington colliery constituted a problem of unusual complexity. As the effects of using auxiliary fans are difficult to gauge, the strictures which Mr. Roberts places on their use are wholly sound and justified.

* "Explosion at Easington Colliery." Price 4s. 6d. H.M. Stationery Office, York House, Kingsway, London. W.C.2.