Circumstances Of Explosion Studied

Press, Volume CVI, Issue 31344, 14 April 1967, Page 3

Circumstances Of Explosion Studied

(From Our Own Reporter) GREYMOUTH, April 13. The “mystery” of an apparent delay between the firing of a shot and the subsequent explosion which killed 19 miners occupied the Commission of Inquiry into the Strongman mine disaster today.

Once again the Greymouth courthouse public gallery was well filled for the hearing, in its fourth day today.

The inquiry has so far revealed that the key for the shot-firing mechanism was found in the left-hand pocket of the deputy Kinsey, but considerable doubt was cast this afternoon whether he would have had time to return the key to his pocket before he was killed, if he had used it to fire the shot When examining an explosives expert, the commission chairman (Mr J. K. Patterson, S.M.) said there were two possibilities—one, that there was a second key; two, that the shot did not cause the explosion. Earlier evidence had suggested that the shot had ignited paper or some other substance which had eventually caused the explosion, but the chairman said that so far there had been no evidence produced of any burning substance near the shot-firing place.

The five-man commission headed by Mr Patterson has as its members Mr W. Elliott, a mine underviewer; Mr S. R. Eyeington, a mine manager; Mr T. McGhie, a retired Buller district manager of State coal mines; and Mr A. V. Prendiville, president of United Mineworkers of New Zealand. Mr R. Savage, of the Crown Law Office, Wellington, is appearing for the Crown. Other counsel are Mr R. A. Young, Christchurch, who is appearing for the Underviewers’ and Deputies’ Union; Mr W. D. Taylor, of Greymouth, for the United Mineworkers’ Union; and Mr D. J. Tucker, of Greymouth, for the mine management. ‘Full Information’ Donald Forrester Brown, the mine manager, told Mr McGhie when the hearing resumed this morning, that he did not agree that the development of Green’s section had been wrongly based. Mr Patterson: “Are you satisfied you have received full information on safety during the six months you have been manager?”—“l think so.” “Truthful information?”— “I would say so.” Mr Brown said he had not had experience in such a big gassy mine before coming to Strongman. His previous appointments were at Reefton and in the North Island. There were seven underviewers underground. Two, possibly more, held secondclass mine managers’ certificates. None of them held a first-class ticket, but one of the 18 deputies did so. New Deputy The deputy who had qualified first-class last December preferred to continue as a deputy. One new deputy had been appointed to succeed the two killed in the explosion. He had sufficient deputies but felt he was overstaffed with underviewers. The number of personnel underground in December was approximately 330—the greater proportion experienced miners.

Questioned further on aspects of the commission’s terms of reference, Mr Brown told Mr Patterson that he would like a greater delegation of managerial duties and

a review of the. shot-firing regulations with research into possible steps to stop the developments of dust explosions. He agreed that more stringent investigation of the 1956 explosion could have been of profit. Manager’s Task He agreed that the shotfiring regulations were impossible to administer fully and the managerial responsibility in such a mine was only “a thin line.” Mr Brown told Mr Patterson that written application and permission from the inspec-

torate before extraction of pillars would probably be of benefit.

There was no record of shots fired in O’Donnell’s work-place on the morning of the explosion in the deputy’s notebook because this was only done after the completion of a round of shots. The round had not been completed when the explosion occurred. Deputy Kinsey would not have made his written report on conditions at that stage of the morning. Re-examined by Mr Savage, Mr Brown said it was unlike-

ly that a shot had been fired from the goaf (worked-out area) side of O’Donnell’s face because there was no road for loading of trucks. The brattice (wooden lining) leading into the goaf was adequate in length to provide proper ventilation of the area.

Normal Course

In the normal course of events O’Donnell and his mate would have drilled the holes in the face and sent for Kinsey the deputy to fire the shots. If he was not satisfied with the face he should not have fired the shots. The miners could have attached the wire from the deputy’s exploding apparatus to the shot but should not have been permitted to do so. If the initial explosion was caused by methane, more stone-dusting would not have halted this, but could have prevented it propagating. Sergeant Leonard MacDonald Simmonds, of the Greymouth police, said that while checking the property of Kinsey he had found what he had taken to be two keys from his pockets. One was a shot-firing key. Ernest Lionel Seilens, chief inspector of explosives in the Department of Internal Affairs, said the principle in shot-firing was to break the rock or coal without throwing it. Permitted explosives were of a type that would not ignite gas or coal-dust and were of short duration at the point of explosive. The flame was low because sodium chloride reduced the temperature. If too big a charge was used there was a possibility of it igniting gases.

A fracture in or near the drill holes would promote an explosion if in contact with methane, and shots required adequate cover before firing. It was important to know the

burden on all sides of the holes, Mr Sellens told Mr Savage.

In October the Auckland inspector had reported that some plugs of Monobel had not been exploded in the Glen Afton collieries when fired by the normal detonator. Reports had also been received from the Liverpool mine.

Investigations were made by the D.S.I.R. The Mines Department had discontinued the use of Monobel: Polar Ajax instead was used. The major difference was that Monobel was not as dense an explosive as Ajax. The Monobel case was 6in long compared with Ajax’s 4in. Ajax produced a more concentrated shattering effect but contained more soduim chloride—about 26 per cent compared with 21 per cent for Monobel. Not Consulted The manager’s instruction to the shot-firers to reduce the use of explosive by a third on the introduction of Ajax last November was a reasonable one. Asked by Mr Young if he knew that Dynobel was now used in Strongman mine instead of Ajax, witness said he had not been consulted about its use. His job was to authorise safe explosives but its use in coal mines was outside his jurisdiction. Mr Sellens told Mr Young that it was likely that the firing of the first two shots had a loosening effect on the face, but he could not readily see how it would have had any combined explosive effect with the third shot apart from the fragmentation of coal. Third Shot He told Mr Prendiville that authorised explosive was only safe when properly used. Mr McGhie asked if there was a possibility of the third shot having detonated the first two charges in O’Donnell’s place but Mr Sellens said it seemed likely that the first two had been detonated earlier. Questioned by Mr Patterson on the regulation which said that only one hole should be charged and fired at a time Mr Sellens said the principle was a major safety factor. It also prevented any accidental firing of other shots and allowed inspection of uncharged bore holes for crevices or breaks.

An explosion such as had occurred would have given the deputy little time to return the detonating key to his pocket Mr Sellens told Mr Patterson. The maximum delay would have been only about a second. Mr Patterson commented that this was a weakness in the theory that the last shot caused the explosion. Mr Sellens said that if the key in the deputy’s pocket was the one used he could offer no explanation. ‘Measurable’ Time Mr Savage referred to evidence by Mr Lundon that the explosion need not necessarily have been spontaneous. Mr Sellers said that after igniting the methane it would be a measurable time before the explosion took part Mr Patterson: “You would perhaps look for a second key?” Mr Sellers said he would say there was a 6040 chance Kinsey did not put the key back in his pocket. David Carlton Syme, deputy on the dog-watch shift which ended on the morning of January 19, said he had checked all work-places and roadways in the rise panel section and they were all free of gas. His report to this effect was signed at 6.20 a.m. About 2 a.m. he had visited O’Donnell’s place. It was free of gas and ventilation was good. He had looked into the goaf but had not inspected it completely as he had done on previous nights because a place in the goaf was now not being worked. Deputies Left Questioned by Mr Tucker he said he was aware that the inspection should have been made in the two hours prior to 7.30 a.m. He told Mr Taylor that it had become the practice for the dog-watch deputies to leave before the arrival of the day shift deputies. He agreed that he could not effectively test for methane in O’Donnell’s area with a booster fan operating. Mr Patterson: In other words you went through the motions?—Yes. Mr Patterson: And later 19 men died?—Yes. Gas Tested Asked if he knew the amount of methane that was deadly, Mr Syme said about 6 per cent. Of after-damp he said it could be 0.1 per cent. Mr Patterson: Would it be 10 per cent?—l don’t know. Mr Syme agreed that he had fired 10 shots in a goaf behind Mountford’s workplace to remove sets of timber. Nothing untoward had happened and he had tested for gas before each was fired. Mr Syme said that O’Donnell's work-place would not have been inspected between 1 a.m. and 7.30 a.m.