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Opinions And Recommendations Of The Consultative Committee.

GOB-STINK. All the members of the Committee have had experience of gob-stink, gob-fires, and explosions in the Bullhurst or other seams in North Staffordshire. From their own observations alone, they are able to affirm that gob-stink was undoubtedly present as set out in the foregoing summary of their inspections, a conclusion further supported by the evidence of experienced witnesses, to which evidence due importance must be given.

SOURCE OF GOB-STINK. It is possible that the gob-stink observed was caused by:

1st. Communication through breaks or fissures in the pillar of coal between the new district and the old district in which explosions occurred three years ago, or (but less likely) the old district which exploded and was set on fire twenty years ago.

2nd. By an undiscovered gob-fire which occurred in the new district and caused the explosion of January 12th, 1918.

3rd. By spontaneous heating in the goaf or working places, or falls of coal and debris in the roadways, subsequent to the explosion.

With regard to the last possibility it now appears, contrary to what was at first believed, that some circulation of air was going on in the Bullhurst cruts from the day of the explosion up to the moment of the discovery of gob-stink.

DANGER OF GOB-STINK. At the time of discovery of gob-stink and the erection of the stoppings, conditions of extreme danger existed, there being a development of spontaneous heating, and at the same time an explosive atmosphere in the main crut.

SUSPENSION OF OPERATIONS. The erection of stoppings and the suspension of operations for the purpose of producing an extinctive atmosphere, needs therefore no further justification.

RESTORATION OF CONDITIONS OF SAFETY. The erection of the stoppings resulted in producing an enclosed atmosphere containing less than 5 per cent, of Oxygen at the various stoppings, and the disappearance of gob-stink on March 27th.

At the date of writing this report, there is less than 1 per cent. of Oxygen at the stoppings F, B and C*.

MAINTENANCE OF CONDITIONS OF SAFETY. Spontaneous heating has, however, only been arrested. Time is required for the cooling down of any heated mass, and if air is allowed to re-enter, dangerous conditions will in all probability be restored. The extinctive atmosphere must therefore be maintained.

RE-OPENING OF GOB-FIRE DISTRICTS GENERALLY. The common experience in North Staffordshire is that attempts to re-open districts once closed against gob-fire lead to a recurrence, and only in extremely rare cases, and after the lapse of considerable time have such attempts been successful.

RE-OPENING OF THE MINNIE PIT, BULLHURST. It will be realised, therefore, that the Committee regard the re-opening of these workings, so soon after established evidence of gobstink, as an operation requiring the utmost care. The carrying out of the work with the minimum of risk to officials, rescue teams and workmen, calls for the highest degree of skill and experience, and the application of the best methods and appliances known in mining science and practice.

EXTENT or RISK. This can only be stated in general terms. The working capacity of rescue teams is often over-estimated. The distances they can safely travel beyond their fresh air base is limited by the obstructions and difficulties met with in the roadways, especially after explosions, and laborious work, such as clearing falls, timbering unsafe roof, carrying material, and building stoppings, involves physical distress not fully appreciated by those having no personal experience in the use of rescue apparatus. The work of the rescue teams in the operations now proposed will be difficult, and a certain measure of risk is unavoidable.

A further risk not only to the rescue teams but to all persons underground, will be the inadvertent admission of air beyond the points explored. The consequence would be the revival of heating and gob-stink, possibly in the presence of an explosive mixture of firedamp and air.

SCHEMES FOR RE-OPENING. Of the three schemes submitted, those of the Miners' Representatives, and of Mr. Saint, have much in common. Exploration in sections after rescue teams have sealed the forward areas by advanced stoppings is the only possible method. This is the more fully set out by Mr. Saint, and in addition his scheme includes details, qualifications, and safeguards which are absent in the other proposals.

MR. SAINT'S SCHEME is therefore, in the opinion of the Committee, the one to be recommended as offering the best prospects of success.

In addition to the foregoing notes on his proposals, the Committee make the following further observations.

SUPERVISION. It is advisable that the operations should be under the control of competent officials who have had experience in gob-fire and rescue work.

RESCUE TEAMS AND APPARATUS. These should be provided by the owners of the mine, thus obviating the necessity of calling upon the Colliery Owners' Central Rescue Station. It is important in the interests of the North Staffordshire Mining district, that the men and apparatus of the Central Station should be available at all times, and at short notice, for emergencies elsewhere.

WORK OF RESCUE TEAMS. Under the difficulties they may be expected to encounter, it is important that their tasks should not be made too strenuous. Much must be left to the judgment and discretion of the leaders. Such working distances from the base as are proposed in the scheme of the Miners' Representatives (10) and (12) will, in the opinion of the Committee, be impossible under the circumstances. A second team fully equipped must in all cases be "standing by,, at the base when the working team goes forward. Means of signalling to the base must be provided.

RESTORING VENTILATION. Before any section is ventilated, a competent person must examine the advanced stoppings and 'assure himself that they are substantially built and airtight. Falls, or accumulations of coal and debris, must be examined for evidence of spontaneous heating, and removed if doubtful.

EXPLORING WORKINGS. This must be done in sections after the advanced stoppings have been built, in the same way as in the main roads. Special care will be necessary to discover possible heating in the working places, at the faces, in disused roads and near goaves.

EXPLORING DESCENDING WORKINGS. Difficulties may be expected in maintaining an extinctive atmosphere in descending or dipping workings such as those over the anticlinal, and it is probable that means such as liquid Carbon-dioxide may have to be resorted to.

SAMPLES AND ANALYSIS. Samples of air from pipes in the stoppings should be regularly taken, and analyses made to make sure that an extinctive atmosphere is being maintained in the enclosed area.

SAFE LINE OF RETREAT. The Committee attach much importance to Mr. Saint's reference to "a good line of retreat." In addition to making the roads good for quick and easy return, the Committee suggest that at some distance behind the point of work preparatory stoppings of strong construction should be built capable of being quickly closed in the event of a recurrence of heating and gob-stink. Some of the stoppings used in advancing could be utilised when they are afterwards in the rear, by suitably strengthening and preparing them for such an emergency.

 

A copy of this report was kindly donated by
West Cumbria Mines Research.