Show small wording wo aking shafts for western metal M mines ines WRITTEN FOR R THE MINING REVIEW BY ARTHUR 0 GATES when a mining property reaches such a point that for efficiency in handling the ore developed and waste produced and for further prospecting that a shaft be sunk certain factors should be considered the function of the shaft is to provide a means of communication with the ore bodies known or unknown beneath the surface to provide an outlet for the rock and ore broken for the water making its way into the workings and to provide for ventilation communication is had by means of the manway by the cage bucket or skip operated from the hoist and through drifts run from the various stations on the shaft the ore and waste rock are hoisted through the hoisting compartment of the shaft to the surface and discharged there water is handled by a bailer substituted for cage etc or by pumps pumps usually are placed in a pump compartment with the steam air exhaust and water pipes running this compartment to the surface r HOIS ft avo 0 o VA 9 ky VA Y 1 J 10 i 2 ar 9 T I 1 L 1 0 1 l S ff 3 0 0 o t y s ing pipes are occasionally carried down the shaft but the shaft itself should act as a chimney and with assistance act as the chief part of the ventilating system of the mine the size of the opening must first be determined ter mined and a study is necessary of the functions of the shaft to determine the space to be allotted to each of itself or combined hoisting compartment it is necessary that one compartment at least be devoted to the raising of ore and waste for lowering timbers pipe and supplies and for handling men to and from i their work underground the size of this compartment should be determined from the quantity of rock it is desirable to hoist and the amount of each load will depend somewhat upon whether hoisting will be done continuously or intermittently as conditions within the mine justify and will be further limited if the load is to be immediately moved on reaching the top of the shaft to waste dump or to ore bins from the amount of each load we can determine the dimensions of the bucket skip or cage As the cage must be built to carry a mine car an arrangement that is less compact than that of the bucket or skip it is the cage that will control the dimensions of the compartment part ment the cage should be large enough to safely contain the car and no more al thought we quite frequently see cars on cages with a foot between the side of the cage and the car extra space here is of no use it is not only not good practice but quite frequently illegal for men to ride on cages when carrying a car empty or load ed and the extra width requires extra weight for proper supporting of the car and spanning of the distance all dead weight when working in a single compartment As we are not dealing with conditions in coal mines or in the iron or copper mines in the lake superior region but with conditions as found in western america and in the smaller mines we can say that eurmine our mine car will hold between twelve and sixteen cubic feet of ore a size that can readily be handled by a single trammer such a car would be 20 to 24 inches high 24 inches wide and 36 inches to 48 inches long inside dimensions of the car body there need be no side projections on the car other than the stiffening bars and we are safe in call calling ng 2512 25 inches the outside width of our car the shaft guides are nearly always wa s fir sized down to about inches and as guides leave little to be desired really only 2 inches of each guide need be within the of the shaft compartment as a shoe extending from the cage need not lap more than two inches on the guide the dogs may need 21 inches of the guide plus vz 12 of an inch for clearance 38 of an inch play between the side of the cage and the face of the guides is ample unless the ground is moving badly between the outside of the cage next to guides and the side of the car we can allow inches for side plate of the cage for car lock and for clearance to summarize we need for the width of our hoisting compartment for car 25 vz inches for car lock clearance etc 3 inches for play of cage in guides ya of an inch and for the guides 6 inches a total of inches slightly under 3 feet it would appear good practice to dap the guides down to 3 inches thick at the sets so there would be some bearing of the guide on the set which should give the guide greater resistance to tearing out a thing that occasionally hap pens when a dropped cage has its safeties work properly with the compartment width determined as 3 feet the length will be determined by the length of the car cars are liable to be loaded on the cage from either side and it is therefore necessary to figure on allowing for the greatest projection to be figured at loth both ends the handle should not project out more than 2 inches so that 5 inches should bo bi allowed tor for it there must not be too great air resistance to the cage when passing the close points especially in a cribbed crabbed shaft and it seems best that we allow the landing chairs to lay within the shaft dl dimensions dimension un um allowance of 2 inches per side for chairs and clearance or for air passage probably being sufficient clent many cage cars are 38 inches long they would require a compartment 47 inches long say 4 feet but these cars on account of their short length are high which makes shoveling harder a tunnel car 44 to 48 inches long has a lower center of gravity is more easily filled and is more easily handled the 44 inch car would require a compartment 4 feet long while 5 feet would be a fair length for the 48 inch car 4 rov r C ilk 4 N 7 2 az A IV V thus the hoisting compartment should only be 3 feet wide by 41 feet long for handling a cage carrying t a 1214 12 14 cu ft car and if the car were 30 inches wide and 48 inches long an extra large unit the corn com apartment part ment size should be 3 feet by 5 feet most hoisting compartments in small shafts are square 4 feet or 41 feet each dimension they are usually made so because this is big enough the tonnage to be handled and depth will determine whether more than a single gingle hoisting compartment will be required and as most small shafts are for prospecting as well as for handling the tonnage and first cost is considered of importance we can safely limit ourselves to two hoisting corn com apartments part ments in a producing mine and to one in a prospect one additional advantage in the narrow hoisting compartment is that we can build a lighter and more rigid cage much of the weight being in the deck and the overhead covering and mechanism and further there should be less danger of a crosshead being hung up than in a wade shaft pump and pipe compartment the quantity of water to be handle hand ledin d 16 sinking is the biggest unknown in our problem and space must be allowed in the shaft for sufficient pumping equipment to take care of sudden rushes of water so far as other conditions will allow we can hardly prepare for 1000 gallons per minute in a small prospect shaft 25 to gallons per minute would be the ordinary condition to look for while or gallons should be considered the maximum if we have more water to take care of it will be necessary to widen the shaft while there are other good sinking pumps on the market the cameron type is by far the most used A no 9 cameron which has a maximum capacity of gallone per minute can go in a compartment feet but in case of a drowning out this pump could not be handled very expeditiously on account of the water columns fl M tf w r i 3 36 3 6 T w A A H r r 11 U 0 0 J tw 4 aaa ft J s 1 U A tf c s above it and there is no spare room around the pump for other purposes of course one dimension of our pump compartment will be 4 feet or 5 feet as determined by the hoisting compartment if we figure on room enough for a gallon pump and a spare pump of equal capacity pump compartments feet or 5 feet square will satisfy this condition when it is desired to continue sinking with a separate hoist placed underground we can hoist from the station in the regular hoisting compartment and from the sinking operation in one side of the pump compartment using a bucket or skip one pump coumbe could be placed in the hoisting compartment and the spare pump in the pump compartment close to the latter so as to give the bucket sufficient clearance by the time a station or two is cut we would have a sta tion pump and by concreting around the shaft cut off of the water which the sinking pump had formerly handled this might reduce the capacity required require cf i from the sinkers so that the spare could be a much smaller pump and in many cases it need only be where it could be lowered quickly to place and connected in case of accident to the regular pump the space between the pumps and the surface would be ample for all the water columns steam air for drilling and ventilating ti and exhaust pipes electric lines etc for ventilating purposes the pipe and pumping compartment is frequently partitioned off from the hoisting by means of boards this compartment acting as a chimney the warm air rising through this compartment part ment and the cold air going down the other it might be that brattice cloth could be used to advantage here instead of boards to keep the air currents from intermingling in the two compartments ladder way communication between points in the shaft must be had by means of ladders when the hoist is not available A wise legal provision in some states is that the ladder should slope from platform to platform same to be not over three sets apart and the opening to the next ladder below in descending sc is under tinder the upper one so that one must made a turn on each platform before proceeding we are naturally limited in our small shaft and must be as economical with our space as possible by using the scheme outlined below per fig 2 we obtain the practical advantages of a separate manway compartment and at the same time have practically lly all our pump compartment available for handling the pumps both the ladders and platforms are fixed in the sense that they cannot be readily removed from the shaft their own weight and the loading of them only serving to 0 press them more firmly into place the platform is placed next to the divider and is about two feet wide is connected with the divider with heavy strap hinges or else is supported next to the divider by a 1 or 2 inch pipe from side plate to side plate running through the bottom framing of the platform and acting as the pin of the hinge about which the platform swings upward to clear the shaft at the outer edges the platform would be supported by strap iron or wooden lugs resting upon the side plates the ladder as shown would be connected to the platform set by a flat steel link L hinged both in the ladder and at the set the lower end sets in sockets in the platform when it is desired to clear the compartment part ment the ladder is raised at the upper end and is held on the slope until the platform can be raised back then the ladder is let back until it hangs in its low position locking over the lower ladder section and holding the platform back by means of a brace B on the latter As this scheme is not in operation several details must be worked out the railings failings rai lings if they are considered necessary method of locking upper ladder over lower so that there is a rigid ladder the full length of the widened compartment part ment outer supports for platforms and the type of hinges interlocking between bea ladder and platform the sketches have indicated a more or less complete solution of some of these but they must be worked out to suit the individual requirements the 71 h tags tag S s sj N V u r AI A i 7 EVA rv platform rail next to the ladder could be hinged and blocked so its frame would be at right angles vh ahon n the platform was in place and in plane with it when swung up above all things there must be nothing that can work loose or under tinder any condition project out into the hoisting compartment no doubt some geiple will object to th thy f folding arrangement but our problem is to obtain all modern conveniences and necessities in the minimum space and it is feces sary that we make the most of the means available if we insist on living in a flat we have to put up with a folding bed or one stowed away in under the bath room the problem of raising a large and healthy family does not take the flat conditions into consideration nor do we try to get along with two compartments in a large mine the final word on the small shaft has not yet been said there are cases where the suggestions made in this article would be of no benefit and there is plenty of room for discussion but it is hoped that to the many small shafts to be sunk in the western mental mines more study shall be given and that they shall be made more efficient in operation ARTHUR 0 GATES salt lake city utah |