Imágenes de páginas

required. In view of this it can be stated that there is a definite hazard of a coal-dust explosion in the Sterling mine or in any other bituminous coal mine that has not been rock dusted unless the mine is extremely wet throughout. Table 1.-Analyses of dust samples collected in Sterling mine, John M. Hirst and

Company, Salineville, Carroll County, Ohio, July 20–27, 1942

[blocks in formation]

2. It is admitted that the Sterling mine liberates comparatively small amounts of methane; however, of samples collected in connection with Federal inspections, one (taken from a borehole) contained 4.14 percent methane; another contained 0.14 percent methane; and two samples collected in connection with the latest inspection (June 1949) each contained 0.10 percent methane. This shows that there is at least some possibility that explosive mixtures of methane might accumulate, particularly with interrupted or deranged ventilation. The Bureau's files contain several reports of disastrous explosions that have occurred in socalled nongassy mines that were caused by wrecked trips of cars throwing coal dust into suspension which was ignited by an electric arc, such as the explosion which occurred in the Stag Canon No. 2 mine, Dawson, N. Mex., in 1913, in which 263 men were killed, and the Dolomite mine, Dolomite, Ala., in 1922, in which 90 men were killed. Moreover, samples collected from the Sterling mine contain approximately the same amounts of methane as the samples collected from the Centralia No. 5 mine before and after the explosion occurred in that mine.

3. It was admitted by Messrs. Holt, Coneybeer, and Williams that black blasting powder, and in some instances dynamite is being used for blasting coal and rock. The firing of black blasting powder in bituminous coal mines, because of its long, hot flame (1,539 milliseconds, or over 1.5 seconds in duration, and 2,215o c. in temperature), is extremely hazardous as a blown-out or underburdened shot may throw coal dust into suspension and at the same time provide the flame or igniting agent to ignite the dust cloud. Moreover, when a dust cloud is once ignited propagation invariably occurs, and the explosion may travel over most or all of the mine or in some instances even to the surface. Hundreds of explosions caused by the firing of black blasting powder have occurred in coal mines, typical examples of which are the explosion that occurred in the Willow Grove mine of the Hanna Coal Co., Neffs, Ohio, in 1940, in which 70 men were killed; and the explosion which occurred in the Midvale mine of the Midvale Coal Co., Midvale, Ohio, in 1931, in which five men were killed. One of these, the Willow Grove explosion, was caused by an underburdened shot, and the one at Midvale by a blown-out shot. Permissible explosives are considered to be 17 times safer than dynamite and 45 times safer than black blasting powder, since the flame from such explosives is 0.342 milliseconds in duration, and from 1,631° to 2,0000 C. in temperature, and is relatively small in volume. Therefore, only permissible explosives should be used for blasting coal and rock in coal mines.

It is believed obvious from the above that a definite coal-dust explosion hazard is present in the Sterling mine and that corrective measures should be taken promptly, as no one can predict when a disastrous explosion may occur under the prevailing conditions. The fact that the mine, as stated by Mr. Holt, has worked about 40 years without an explosion is no guaranty that an explosion will not occur tomorrow. Other mines worked as long or longer without explosions and yet disastrous explosions and fires have occurred in them.

Other hazards of a serious nature exist in the Sterling mine, particularly with respect to a fire hazard, since the installation and maintenance of electrical wiring and equipment are very poor. Moreover, since the escapeways, (other than the main haulage road) are not travelable, in case of a fire or an explosion it might be extremely difficult, if not impossible, for the survivors of an explosion or men trapped by a fire to escape.

Mr. Coneybeer made a statement that during his last inspection he found only five violations of the State law, which he recommended to be corrected. However, if we have properly interpreted the Ohio mining law, at least 25 violations of the State law existed at the time of the last inspection, since the violations of the Federal code that are stated in the report of inspection are in many cases also violations of the State mining law.

To show the indifference to hazardous conditions that prevail, particularly in small mines, but also to some extent in larger mines, on the part of the State mining agencies and operators, the following record of events following a Federal inspection of a mine in Virginia is included as it is believed it will be of interest to the subcommittee: The mine is the Blankenship and Ballard mine, operated by coowners Roy L. Blankenship and Leslie Ballard, located approximately 4 miles southwest of Whitewood, Buchanan County, Va., and employing 15 men underground on 2 shifts. The mine was first inspected by a Federal inspector on May 3, 1949, and the inspection revealed the existence of the following hazardous conditions and practices that were considered to be imminent dangers:

1. Coal was blasted on shift with black blasting powder ignited with fuse. 2. Excessive accumulations of coal dust were present along each haulageway.

3. The surfaces of the mine were dry, but rock dust had not been applied in the mine.

A preliminary Federal report calling attention to these imminent hazards was prepared by the inspector and posted at the mine on May 5, 1949, for review by the mine personnel and other interested persons.

A final Federal report covering the May 3, 1949, inspection' was prepared by the inspector, and was transmitted from the Bureau of Mines office at Norton, Va., on May 13, 1949, to Roy L. Blankenship, coowner, Richlands, Va., the Laurel Fork Coal Co. lessor, Richlands, Va.; C. P. Kelly, chief, Virginia Department of Labor and Industry, Big Stone Gap, Va.

The final inspection report_gives a detailed description of the mine, and includes all violations of the Federal Mine Safety Code observed (19) together with recommendations to correct the hazardous conditions and practices.

On May 6, 1949, Mr. W. H. Tomlinson, engineer in charge of the Bureau of Mines field office at Norton, Va., advised Mr. C. P. Kelly, chief of the Virginia Department of Labor and Industry of the imminent hazards that were observed in the mine during the Federal inspection of May 3, 1949, i. e., (1) use of black powder ignited by fuse for blasting on shift; (2) excessive accumulations of coal dust along the haulageways; and (3) the mine was dry, but rock dust had not been applied. The Tomlinson letter indicated specifically that unduly hazardous conditions from the standpoint of a widespread explosion existed in the mine; copies of the letter were also sent on May 6, 1949, to Mr. Roy L. Blankenship, coowner, and to the Laurel Fork Coal Co., lessor.

On May 27, 1949, Mr. J. J. Forbes, Chief of the Health and Safety Division, Bureau of Mines, sent a letter to Roy L. Blankenship, coowner, which called atention to the unduly hazardous conditions and practices that existed in this mine as indicated in the final inspection report, and requested Mr. Blankenship's cooperation in eliminating the hazards.

On June 3, 1949, an explosion occurred in the Blankenship and Ballard mine; the explosion resulted in two of the four men underground and one of the seven men on the surface being severely burned on the neck, face, hands, and arms.

The Federal Bureau of Mines had no knowledge of the explosion until 5 days after it occurred. The Federal investigation made on June 8, 1949, revealed (1) that the mine had resumed operations on June 6, 1949; (2) that the explosion probably was caused by one or more blown-out shots raising into suspension and igniting coal dust; (3) that black blasting powder ignited with fuse was still being used for blasting; and (4) that the small amount of rock dust that had been applied in the mine on June 3 (following the explosion) was definitely not sufficient to prevent the propagation of another explosion .


Mr. KELLEY. Are Mr. Coneybeer and Mr. Williams here?
Mr. WILLIAMS. Yes, sir.

Mr. KELLEY, Mr. Williams, and Mr. Coneybeer, you might as well both come up.

You are Mr. Williams?
Mr. WILLIAMS. That is right.

Mr. KELLEY. And you are the chief inspector of the State of Ohio, Division of Mines?

Mr. WILLIAMS. That is right.
Mr. KELLEY. And you are the district inspector?
Mr. CONEYBEER. Yes, sir.

Mr. KELLEY. You heard all of this testimony; what do you have to say about it?

Mr. WILLIAMS. What I have to say about it may take a big bookMr. KELLEY. You made an inspection of the mine, what do you say? Mr. WILLIAMS. My experience with this mine goes back a long time. Thirty years ago, as deputy mine inspector, I made an inspection of that mine, and then last April, due to the things that have been brought out by the Federal coal mine inspectors, I made an inspection of the mine and tests to study conditions in the mine.

Of course, I am not going into any more detail than what is considered imminent danger, if any. This mine is not open to imminent danger insofar as dust is concerned.

Mr. KELLEY. Insofar as what is concerned ?
Mr. WILLIAMS. Coal dust is concerned.
Mr. KELLEY, Coal dust?

Mr. WILLIAMS. Yes, sir. We took samples of the dust in the mine and analyzed those samples, and we are unable to find coal dust that constitutes danger. Part of the dust is such that it has a high ash content. In the operation of the mine, the coal is mined at a depth of 442 feet, and the extraction of the coal is very slow, and the dust is not made and thrown into suspension as it would be if it were a mechanized mine, and the extraction was more rapid.

Mr. KELLEY. I thought dust was along the haulage roads and on the roof, ribs, and timbers.

Mr. WILLIAMS. The dust along the haulage road has an ash content of 50 percent to as high as 90 percent, and such dust will not explode.

Mr. KELLEY. Did you ever send it to the Bureau of Mines to see whether it would or not? Inert matter will explode sometimes.

Mr. WILLIAMS. They do say that you can explode cork, but when you are speaking of coal dust, you have got to have coal dust and not ground and sand.

When the Federal mine inspectors came on in 1942, the first inspection I have a record of, they ran an analysis of this dust, but since that time they have made no analysis because of the policy of the United States Bureau of Mine Inspectors that all mines should be rock-dusted, and they will not take samples in places that have been rock-dusted after they first visit the mine.

Mr. KELLEY. The Ohio State mine law does not require mines to be rock-dusted.

Mr. WILLIAMS. Yes, sir; it requires mines to be rock-dusted where the dust is in suspension in such quantities that it is likely to create an explosive hazard, or where accumulations of such dust would accumulate.

Mr. KELLEY, Could not a condition like that arise rather suddenly! You inspect the mines how often, about every 3 months ?

Mr. WILLIAMS. A mining inspector is supposed to visit the mines once each 3 months.

Mr. KELLEY. Once each 3 months ?

Mr. KELLEY. Between those inspections a condition could arise that would be an imminent danger where there might be an accumulation of rock or coal dust?

Mr. WILLIAMS. Well, it could arise, provided you changed your system of mining.

This mine is mined over considerable territory. If these things that are being talked about were likely to happen, why, it goes without saying they would have happened between now and the more than 40-year period since 1901 when the mine was opened.

That this mine is to be classed as one of the most dangerous mines in this country, I take exception to. That mine in its normal operation and the conditions which surround it is one of the best mines in the State.

Mr. KELLEY. How can there be so much divergence of opinion here?

Mr. WILLIAMS. That is a matter of how you arrive at your conclusion. If men have a certain policy to follow, everything is considered imminent danger. I can see that our Federal men stick to their side of that question, but we examined the mine and took and checked samples of the air and dust and we do not find those conditions.

Mr. KELLEY. And you say that the ventilating system there is perfectly satisfactory?

Mr. WILLIAMS. I do not say that it is satisfactory all through the day, but the ventilation extending down into the mine where the men work is above 20 percent, and has been for some time, and I am not condoning anything that in any way creates a hazard or that is likely to have people injured.

Mr. KELLEY. Let me ask you this question, since you are defending that mine. After these inspectors have said it is such a hazardous one, would you be willing to say that there could be no explosion in that mine?

Mr. WILLIAMS. There could not be under its present method of operation.

It was brought out here that there was so much explosive used in the mine. The very small quantity of explosives used to blast that coal is such that you are not likely at any time to have a blown-out shot. If you are going to set dust off in a coal mine from an explosive point of view, you have got to have volume of it enough to go out there somewhere to kick up that dust to start it off. I am not saying that you cannot go in there and create a condition, and that it cannot happen.

Under the Ohio mining law, we are compelled to make examinations where dust is thrown into suspension by the mining operations, and those mines are rock dusted. Before this law that was mentioned

here in the testimony, we did not know anything about it. After August 26 of this year any mine that is dry must be rock dusted.

Mr. KELLEY. This mine will be too, then ?

Mr. WILLIAMS. Sure, it comes under that, and our determinations are different. At the present time I would be compelled to prove my case that the operation of that mine makes dust to make it an explosive hazard.

You can go into that mine and any mining operation where the mines are operated mechanically, and regardless of the fact that they put water on the cutter bars and they are rock dusted more and more, yet they have more dust than that mine has without doing anything at all about it, because you do not see that dust in suspension in that mine.

Mr. KELLEY. Suppose there is coal dust along the haulage road, would there be enough coal dust thrown up in suspension there to cause an explosion, especially where trolley rails or a spark might set it off? You told me the high ash content would prevent it. Is there the same ash content along the haulage road?

Mr. WILLIAMS. I know we took samples off the ribs, off the timbers, and off the floor, and we did not find a rock-dust content that would explode. If you had a longer line, extending for a mile or so, if that dust came off those cars, you could have an explosion. You could have an explosion in any mine regardless of the rock dust, but first you must have an explosion.

There is nothing in that mine that would lead me to believe that there is imminent danger as far as dust or gas is concerned. It is not unusual to find a small quantity of gas from the fact that bituminous coal is rapidly broken up. You can get a small reading of gas. Now, the highest content of gas found in that mine was found by a Federal mine inspector in a drill hole. If you bore a hole far enough in advance it could be full of gas. If you take a reading of that it might have a high percentage. If you bring that gas out of the hole and put it out in the atmosphere, under the law of diffusion it is diffused to such an extent it is no longer explosive.

Mr. KELLEY. You should think from the testimony here about the poor ventilation that exists that you might have an accumulation of gas.

Mr. WILLIAMS. That is very well stated, and if such a condition exists, then when a man goes in with an open light and there has been no examination made, gas was never touched off ?

Mr. KELLEY. God is looking after them.

Mr. Williams. No. Almighty God does not regulate gases in the mines; it has to be done by man.

Mr. KELLEY. If a man goes in with an open light and does not know if there is an accumulation of gas-an accumulation up to an explosive point-he pays with his life to find out.

Mr. WILLIAMS. That is true, and if he goes into this mine and there are the conditions that they claim exist, the gas does not accumulate. It goes to prove one thing-that it does not make the gas.

Mr. McCONNELL. Why are they buying a new ventilating fan if everything is 0.K.?

Mr. WILLIAMs. Because the mine is getting deep, and they have to increase the ventilation as the mine gets deeper. You have to have more powerful machinery. You cannot ventilate a mine by natural

[blocks in formation]
« AnteriorContinuar »