Show ELECTRIC FIRING IN COAL MINES the advantages of electric firing are 01 OD and admitted for one thing it is safer if a misfire occurs it is safe to go to the face to investigate and rectify the trouble because it is certain that the charge is not going oft off at all if it does not go the instant the blasting machine is operated this saves time in case of a misfire with cap and fuse it is necessary to wait a considerable sid erable time before investigating because the miss may be due to a break in the powder train of the fuse or some other slight defect in the fuse and there is always a possibility lity that the charge may go sometime after it is normally due As to comparative cost of electric blasting and cap and fuse blasting there is but slight difference an ordinary no 6 blasting cap and six feet of fuse will cost a fraction of a cent the same as a no 6 electric blasting cap with six feet of wire the objection on the part of miners to generally adopting electric firing is ba based sedal almost wholly upon the cost of the blasting machine and the leading wire however these items should be looked upon as first cost equipment and when properly taken care of will last a long time that most mosi miners prefer electric firing is proven by the fact that we often find them using ordinary dry cells to fire their shots of course they fire but one shot at a time but this results in great waste of time after one of these single shots they must return to the face prepare another single shot ana continuously repeat this operation until they have blown down the unit of coal desired ly by using a blasting machine a number of holes could be loaded and fired simultaneously the clearing away after each single shot would be avoided the time tseu in walking back and forth to the end of the leading wire would be saved holes could be so located as to obtain a cumulative et feet at the time of firing the blast this is impossible when cap and fuse is used or at ai any rate involves considerable risk miners try to time these dependent shots by cutting the fuse of different lengths but an all practical blasters know that fuse cannot be depended upon to burn exactly uniform AS a result it frequently happens that a snut or hole intended to follow some other SHOT actually goes off ahead of it this may cause complete failure to obtain deserea results may add more or less heavy expense in the loss of explosives and may even r result in a shortage of coal for the following days work such chance of failure can be avoided only in one of two ways 1 the use of a blasting machine 2 by using delay electric igniters ig niters however the latter increases the cost of production and unlike the blasting machine the cost of delay igniters ig niters is not a first cost it is a continuing cost from day to day in view of the many advantages both to operator and miner of electric blasting with a standard make blasting machine it would seem that the operators would find a way to provide their miners with blasting machines if they cannot make the miners see that it would be worth their while to provide themselves with the machines they could undoubtedly convince themselves that it would pay them to buy the machines themselves for the use of their miners payment for one death or serious injury under an employers liability law woula involve an amount that would provide blasting machines for any larger mining operation for years to come it if considered from that standpoint alone it would undoubtedly pay mine owners to supply their miners with blasting machines however there are many other reasons applicable to the subject among them increased outa output ut due to the saving of time miners and operators should get together on this subject of electric blasting their interests ar are e common and unquestionably some way could be argued upon between them whereby electric blasting could be universally ver sally adopted in the coal mines of the united states |