January 26, 1917. 177 _______________________________________________________________________________________________________________________________________________________________________________________ other was evidently filled, but either the bridge wire or the iron lead wires were broken. It sometimes occured that a cartridge of deteriorated explosive found its way into a shot-hole. Ord in airily, the shot-firer may readily detect such cartridges, because of their being either unusually hard or soft. If, how- ever, such a cartridge is used, the report of the blasting cap may generally be heard quite distinctly, but the charge of explosive fails to detonate. In two or three instances, miss-fires were the result of blasting caps becoming detached from the cartridge. This was due to the cap working loose during the charging of the shot- hole. In the case of miss-fires due to either of the first two causes, the remedy lay in the repair or replacement of cable or battery or in re-establishing a broken contact. On the other handf the last three causes of -fires always involved the drilling of a new shot-hole. It was the general practice to circumscribe the hole with a rough circle at least 12 in. in radius, and instruct the miner to drill a new hole outside the circle, and parallel to the original hole. In any case, the miner was for- bidden to drill out the contents of the miss-fired hole, and reminded of the dangers of that procedure. When it became necessary to fire a second charge following a miss-fire, it rarely, if ever, happened that the first charge was exploded. Therefore, the miner was required always to search the shot-down coal, to locate the cart- ridges of the charge that failed. These were generally ready for inspection by the shot-firer on foils next visit to the working place. In the firing of the shots discussed in this paper, there were no so-called windy shots, and only one blown- out shot. The latter was in an entry, -and was a sima'll charge intended to break down the coal remaining after the coal broken by the tight shot had been loaded out. The blown-out shot was apparently caused both by a charge that was too light and a hole that was slightly in the solid. Shot-Firer's Report. The following form of report for shot-firers has been found useful in checking up the,work of the shot-firers, and in determining the cause of any difficulties in shoot- ing. Also, it serves as a daily reminder of the necessity for exercising care :— Ford Collieries Company. Shot-Firer's Report. ___________________...........................Mine Section No.............. Date...,............... ............................................................ ............................................................ 1. Did you examine each place for gas and other dangers before firing? ..................................................... 2. Did you give warning to persons in adjacent places?......... 3. How many shots did you fire to-day?............................ ______________________________ ............................................................ ............................................................ 4. Give location of any place in which you refused to shoot, and reason ............................................................................ 5. Miss-fires. Location Cause 1............:......................;.................. 2 ............................................................................................................ 3 ........................................................................................................... 6. Blown-out Shots. Location Cause 1............................................................................................................. 2 ............................................................................................................ 3 ............................................................................................................ 7. Did you examine each place for all dangers after shoot- ing? ........................................................................................ ......................... ......................... Mine Foreman. Shot-firer. Precautions in Shot-Firing. The most esservtiial precaution to be taken in 'an effort to safeguard the firing of shots is in the selection, of properly qualified men to do the work. Moreover, it is especially desirable that one or two competent men be made available to act in the capacity of shot-firer in case of the -absence of the regular incumbent of that position. It is a dangerous practice to place the battery and wire in the hands of a partly-qualified man, and tell him to shoot during the shift. Nor is it sufficient, as a rule, to assume that because a man was once con- sidered competent to act as shot-firer, he will always continue to be careful in the performance of his duties. It is advisable to issue special instructions from time to time for the purpose of keeping shot-firers alert and informed of any dangerous practices to be avoided. The importance of giving adequate warning before shooting ought never to be lost sight of by the shot- firer. The best practice is to warn all men on. all sides within -dangerous proximity to the charge, then to call out loudly to warn persons approaching from other parts of the mine, and wait five or ten seconds after calling ___________________________________ A gas explosion has occurred in the Oyama jut, the largest of the Fushun coal mines, belonging to the South Man- churia Railway. Of 1,138 men who were below at the time, 1,000 are missing. ... Sulphate of Ammonia in the United States.—The increase in production of ammonium sulphate in the United States during .1916 was the greatest recorded. The Barrett Com- pany, of New York, has recently given out its estimate of the actual production of all ammonia at coke and gas plants as 325,000 tons (sulphate equivalent). This shows an increase of .47-7 per cent, over the production of 220,000 tons in 1915. By-product coke ovens produced 272,000 tons, or 83-7 per cent, of the total. It is probable that the full capacity of coke ovens and’ gas works will reach in 1918 580,000 tons or more of ammonium sulphate, i.e., about 120.000 tons of nitrogen. The demands of the industries for nitrogen both in ammonia and in nitrate of soda (exclud- ing export products and fertilisers), do not exceed 70,000 toms of nitrogen per annum. For ammonia alone they are not over 25,000 tons of nitrogen. THE COLLIERY GUARDIAN. THE SIZE OF MINE CARS. In a paper read before the Rocky Mountains Branch of the Canadian Mining Institute, Mr. J. Holden discussed the many aspects that should be taken into consideration before any definite type of car is chosen ; the size of the mine car, its shape, construction and weight, together with the track gauge, having a most important economical bearing on the successful working of a coal property. The paramount idea in designing a mine car is to transport the maximum amount of material at a minimum cost. Therefore, the design of the car must be such that under a given height, pitch, and other local conditions, it can be moved, loaded and controlled economically with safety. The chief phases to be considered are: roof conditions, friability and fragility of the coal, height and pitch of the seam, condition of the mine as to it being a wet or dry one, local faulting, and, last but not least, market demand. With the idea of moving material as cheaply as possible there has been a tendency to advocate the use of large steel cars and heavy rails ; but heavy cars and rails in the more or less confined space at the working face are bound to be unwieldy. Along well-lined, dry, and ballasted main haulage roads they are a success. Derailments are few; these, and any that may occur, are quickly re-railed by the motive power and replacers. The ultimate economy of an operation being maximum efficiency, every phase of the operation must be enquired into. It is at the working face that the coal is loaded to keep fcthe main haulage working at full capacity. The supply of empties must be regularly kept up. Any delay here is vital, since no matter how fast one can speed up a haulage to overcome a congestion, the efforts of the loader cannot be made any greater. Also, it is at the face that derailments are most likely to occur, the tracks here being more or Jess insecure, through insufficient ties, unskilful tracklaying, lack of fishplates or some other minor defect. Tore-rail a heavy steel car loaded with coal is no light task in a working place, since the tracks are seldom ballasted and, for the most part, are laid as cheaply as possible; hence when a car jumps the rails they usually spread, and must therefore be relaid before operations can again be started. With a moderate sized car the effect is not so serious. Derailments, however, are just as likely to o *cur, but the loaders and driver, or pusher, can remedy this without getting outside help. The car and track should be designed to meet the requirements of a given mine; not the mine made to suit a certain type of car that may have given excellent results in some other field; for unless the working and labour conditions are the same in both instances, it is highly improbable that the car will be as successful in the one as in the other. The nature of the labour supply has an effect on the size of a car in many instances. In some fields practically all the haulage—putting, driving, caging, loading—are done by boys from ten to sixteen years of age. For this class of labour cars must of necessity be easily handled and filled, and, therefore, of a size that will suit that labour. Whilst standardisation is a good thing, once the proper type of car suitable for existing conditions is found, care must nevertheless be taken that the adoption of a standardised car does not standardise the mine to its detriment. Tracks should be of a moderate gauge, say 36 in. to 42 in. wherever possible—with a preference towards the latter. This gives a good wide car, and there is no need for any excessive overhang, which makes the car weaker, and harder and costlier to construct. With a propor- tionate length the carrying capacity will be large. Tracks of this gauge are very practical: They give a solid to the traffic and offer no difficulties in the way of wide roads. In the district of Drumheller the gauge is about 26 in., and the tracks are harder to keep up than the moderate gauge. There is no reason for a narrow track unless the conditions of the seam make it compulsory, such as the roof conditions being so poor that the unsupported areas at room necks and branch roads must be restricted to snch an extent that a short radius curve is necessary at the entrance to the room necks. They reduce the carrying capacity of the car, which is more likely to jump the rails; and the rails, in turn, are more unstable. The maintenance of both car and track is greater. Nevertheless, under friable and treacherous roofs they have their advantages, the main advantage being in their ability to go round a shsrp curve. Such curves, however, give jerky running, which not only increases the resistance due to the curvature, but also spreads the rails, thus causing delays to the haulage. With a broader gauge there must be a greater radius of curvature, and. therefore more open or unsupported ground; but, under normal roof conditions, this should cause no anxiety. The advantages accruing from this system are: Fewer cars for a given output; greater stability of cars ; firmer tracks and fewer derailments ; a much reduced initial cost. Tracks are firmer, hence derailments and lower maintenance of both rolling stock and rails. Height in a mine car is not by any means to be desired. High mine cars require more labour to load, increase maintenance of roads, decrease stability of the structure, and, if the coal is intended for the domestic market where lump coal is the principal demand, they are not to be advocated, for they lend no inducement to the loader to load large coal. In a flat seam of good height, a fair roof, and normal conditions, the haulage problem is not difficult—the right type of car should easily be obtained; but should all the conditions exist in another seam, excepting that it is a thin one, then the design of the car calls for serious consideration, for much brushing may have to be done. The design of a car suitable for both entries and rooms when the seam is thin should be thought out from the room standpoint only, since the cost of labour to a great extent decides whether the operation will be a successful one or not. It would cost too much to brush all the rooms ; and conveyors have not yet proved themselves an overwhelming success. Hence, the car must go to the face to be loaded, and therefore must below enough to permit the loader to load it with as large pieces as he can lift into the car. To do this, the height of the room must be kept at the maximum. The car should be light enough to be moved readily, for, in a low seam, a man’s exertions are limited. In a pitching seam suited for McGinty or similar haulage, a light car should be used, and if the car is made on the lines advocated above, tare will be less to the load, and will give the maximum pull on the rope for the least weight; hence there is less strain on the rope for a given tonnage of coal, and less risk of accident. A seam pitching sufficiently to permit the cars being loaded from chutes has very few car prob'ems. Advantage should be taken of the thickness of the seam and other existing local conditions. If this is done, minimum haulage costs can be attained. Entries and gangways should be driven wherever possible on a grade sufficient to gravitate water. Tracks should be lined; there should be a sufficiency of ties ; the main roads should be well ballasted, and the steel should be of sufficient weight to bear the tr flic. Cars should be built strong enough to withstand the haulage, yet light enough to suit the local conditions. Their capacity should be as great as circumstances will permit within moderation. The close-end type of car should be chosen in all circumstances, as the old-style cars are the cause of many accidents tohaulage workers through ordinary derailment. Through their inabi ity to retain the coal dust during tranportation they have been the cause of terriffic dust explosion. A gain, at times when the doors have not been securely fastened, blocks of coal have rolled onto the haulage way and caused serious wrecks. The initial cost of the other type is less, and the cars are stronger, for a given tare. The upkeep of both tracks and cars is less, and the friction between employer and employee through the loss of coal by faulty doors is eliminated. The loader is always assured of his weight at the tipple. The tracks do not need so mwh cleaning; and the mine especially if the coal is cf a fragile nature, is safer. These advantages outweigh any that can be claimed for the end-door type. Arguments have been put forward that the rotary dump breaks the coal, but it is doubtful if it causes any more breakage than any other type. COAL MINING ON VANCOUVER ISLAND. With the specific purpose of promoting the com-, mercial and industrial interests of the various parts of Vancouver Island, a number of prominent Canadian business men visited the locality recently. At Cumber- land they inspected the property of the Canadian \ Collieries (Dunsmuir) Limited. The Canadian Colliei ies spent recently in development alone approximately 3,540,000 dols., 2,000 tons of coal are being taken out every day at present, and a power plant has been installed at Comox Lake of 11,000-horse power. The huge electrically-driven drum, around which winds 7,600 ft. of steel rope, was put in motion. The coal was screened for the benefit of the visitors. The company is operating at the mine known as No. 8 shaft, a new . development. In addition there are No. 4 slope at Comox Lake, from which the coal is hauled miles by electricity to the tipple; No.’ 6 shaft, 400 ft. deep in Cumberland; and No. 5 shaft, with a depth of 300 ft. - On the homeward trip, a largely-attended meeting followed dinner at Nanaimo. Mr. H. B. Thompson, of Victoria, urged that something should he done to utilise the iron ore deposits of Vancouver island. One difficulty in this connection is that of a supply of fuel. He suggested that coal by-products, such as aniline dyes, might be manufactured at such a profit as to make coke cheap and plentiful. If this should be found practicable the fuel problem would be solved and future prosperity assured. Mr. Thos. R. Sockett, manager of the Western Fuel Company, said that those at home were doing their bit bv trying to keep the wheels of industry moving. The Nanaimo mines were producing to their capacity. Thei old No. 1 mine was better to-day after 30 years’ operation, than ever, and would be going as strong in the next similar period, barring unavoidable mishaps. Four or five miles to the south there were mining developments which promised results. The preliminary work was hard and expensive, and the advance expected had not been made, but it was coming soon. It would mean much to the community and to the island. His company, he was proud to say, would have taken out 600.000 tons of coal from the two openings this year. This would make it the best in his 13 years’ experience. Next year it was expected to mine 800,000 tons and then 1,000,000 in the 12 months. When the latter figure was reached the ambition with which he started would have been realised. As to Mr. Thompson’s suggestion, he said that there was some coal which would not make coke. Scientists have been unable to discover the reason or to find the missing link in the composition of the material. The coal at the company’s new reserve mine was amenable but the c»'ke would be high in pr;ce as the time had not yet arrived when there was a sufficiently large market for the by-nroductR on the Pacific Coast to bring it within the limits of an industrial fuel. The day was coming when it would be, and then there would be no doubt of the island’s future, because rolling mills would be assured.