222 THE COLLIERY GUARDIAN. August 4, 1916. take its place. This may take the form of peat, electric energy, coke, or a combination of all -three. In so far as peat is concerned, there are undoubtedly areas where it may be used to a small extent for domestic fuel, but its greatest use will, probably, be in the genera- tion of electric energy at the bogs. Hydro-Electric Prospects. Over 175,000 horse-power of the hydro-electric energy generated in Canada is utilised in the electro-chemical and metallurgical industries. In the field of domestic cooking we may attribute the cause for the substitution first, to.convenience, and, second, -to reasons of economy. The rates considered some time ago to make electric heating economically possible varied from one-eighth to one-half cent per kw. It would be difficult to predict exactly what the future has in store in connection with the total substitution of hydro-electric energy for coal in the different uses where heat only is required. That it is a practical possibility has already been demonstrated in almost every use one can think of, so that the only problem to be solved is that of cost. The cheapest development, under present conditions in Canada, can supply hydro-electric energy at, say, lOdols. per horse- power year. If we compare the heat equivalent of coal with the heat contained in this electrical energy, after allowing a loss of 30 per cent, in the theoretical heat of the coal, we find the equivalent rate for electricity to be 11 dols. per horse-power year. This condition, however, assumes that the heat will be used for 24 hours per day during the whole year—a condition which does not exist for ordinary industrial uses and domestic heating. If we consider that the electricity or heat will only be required for half the time during the period, then the price to compete with coal would have to decline to half the amount stated, or 5-50 dols. per horse-power year. These figures refer to present conditions, and although the margin seems wide between 10 dols. and 5*50 dols. per horse-power, the increase in coal prices and progress in hydro-electric development will both tend to bring them closer together. Uses of Coke. In Canada, gas coke (inferior to by-product coke) is used to a considerable extent for domestic heating purposes, and is sold at a price very little below that of anthracite coal. On account of the high price of anthra- cite in Canada, and the necessity for its use as fuel for ordinary house heating boilers during the winter, there seems to be a good opportunity for the installation of small by-product coke ovens at well-chosen points. These localities should be on the St. Lawrence or Great Lakes route. Where proper markets exist, the profit would be that approximately represented by the difference in the price of coal as compared with the selling price of a ton of coke; in other words, the returns from by-products would cover all other charges. Gas companies have not taken this matter up because their main product is gas; while, in the suggestion outlined above, the main product is coke. Distribution of Coal Sales. The distribution of coal sold in Canada is as follows :— (1) Nova Scotia bituminous coal is used only as far west as Cornwall, Ontario ; (2) United States bituminous coal is used from Farnham, Quebec, to a line drawn from Battleford to Moose Jaw, and thence to Es-tevan, Saskatchewan. Although a considerable quantity is used in Manitoba and Saskatchewan, these provinces are also supplied by coal from the Crow’s Nest, Edmonton, Lethbridge, and Souris districts; (3) Vancouver island coal is sold over a very limited area; large quantities are exported to the United States. Oil-burning locomotives are used on the Canadian Pacific Railway from Vancouver to North Bend, and from Kamloops to Field, British Columbia; on the Grand Trunk Pacific Railway, from Prince Rupert to Jasper, Alberta ; on the Great Northern throughout the Cascade division; and on the Esquimalt and Nanaimo Railway on Vancouver island. Nova Scotia Coal.—Nova Scotia coal is shipped to Montreal by way of the St. Lawrence route, but, on account of the closing of the river during the winter months, shipments cannot be made during this period, consequently large stock piles are made at or near Montreal during the open season. The coal used on loco- motives between Montreal and Ottawa is half Nova Scotia and half United States coal—the former -is used to coal locomotives leaving Montreal, while the latter is used on those leaving Ottawa. From the above it may be considered that this is the economic limit to which Nova Scotia coal may be used. United States Coal.—On account of its bulk, the chief factor in the economic marketing of coal is low trans- portation charges. As the water transport charges on coal for 600 miles on the Great Lakes is less than one-half mill per ton mile, as against 6*6 mills per ton mile for coal hauled a similar distance from the west eastward, it can be seen that shipment by water of American coal towards the west has a distinct advantage over western coal, in so far as the middle west market is concerned. Price of Coal at Winnipeg. The following example is a comparison of prices of United States coal and (say) Crow’s Nest coal laid down at Winnipeg :— Dols. Price (per ton) of United States coal f.o.b. Cleveland ............................. 2-15 Freight charges to Fort William (per ton) ... 0-30 Handling (per ton) ...................... 0-30 Duty (per ton) .......................... 0-53 Total cost * at Fort William ............ 3-28 Freight rate from Fort William to Winnipeg 2-50 Total cost at Winnipeg .............. 5*78 Cost of Crow’s Nest coal f.o.b., Crow’s Nest district, say .......................... 2-10 Freight rate from Crow’s Nest district to Winnipeg .............................. 4*65 Total cost at Winnipeg .............. 6*75 * At the present time there is an additional war tax of 16c. It will be noted that the freight rate on United States coal from Fort William to Winnipeg, a distance of 428 miles, is 2’50 dols. per ton, while the freight rate on Canadian coal hauled eastward is 2’50 dols. per ton for three-fifths of this distance. The railways, no doubt, have a good reason for charging the higher freight rate, but the fact remains that it favours the marketing in Western Canada of United States coal. Utilising Low-Grade Fuels. Two problems of great importance exist in the Prairie provinces to-day, and their solution will become a matter of even greater moment in the future. These are : the problem of cheap power and the problem of a domestic fuel supply. In Western Manitoba, in Saskatchewan, and in Eastern Alberta, water power development costs are, in most instances, high, but these districts are within reach of great deposits of lignite. It is, therefore, of great importance that something be done with a view’ to utilising the low-grade fuels which underlie the greater portion • of Alberta and part of Saskatchewan and Manitoba. In order to make the coal transportable and suitable for domestic and power purposes it would be necessary : (1) That it be of sufficient value to bear the cost of transportation; (2) stand handling and a certain amount of weathering; and (3) be suitable fuel for domestic and power purposes. Coal briquettes fulfil these conditions, and it is desirable that investigations be carried on with a view to determining the suitability of the lignite and low-grade coals for the manufacture of briquettes. The Saskatchewan Government has done considerable work along this line. The experience of the United States and Germany has demonstrated that cheap power can be produced in gas engines from lignites inferior to those in the Prairie provinces, and it is believed that electric energy can, at certain localities in the west, be generated from lignite or sub-bituminous coal and supplied to the market at a less cost than the power in use at present. Investigations carried on by the Mines branch of the Canadian Depart- ment of Mines have demonstrated the suitability of these low-grade coals for use in gas producers. Oil Fuel. Oil fuel is used to- a considerable extent in Western Canada. It is impossible to estimate to what extent oil has replaced coal, but according to “ Railway Statistics,” about 40,655,000 gals, of oil fuel were used in that district. Assuming that 3’86 barrels of oil (42 U.S. gallons) are equivalent to one ton of coal for steaming Fig. 1.—Cross-section of Shaft. purposes, then this figure would represent the replacing of about 114,000 tons of coal. On account of its impor- tance to coal operators in British Columbia and Alberta, a fair understanding of this question is necessary. The development of fuel oil for use on railways and steam- ships has been brought about by the discovery of a large oil fields in California. Oil fuel has many advantages over coal, but its use or non-use will, of course, depend upon whether it is the most economical fuel to use under the circumstances. In this connection it might be said that the railway companies have adopted its use, not on account of any compulsion on the part of the Govern- ment, but from business considerations. On account of the ease with which it can be fired, loaded into boats, and • that it occupies less space than coal, thereby giving greater freight carrying capacity for steamships, it will be used on this class of traffic some time after its price exceeds the price of its equivalent in coal. Oil fuel has been used to a considerable extent on railways in the United States since its introduction in 1900. The partial exhaustion of oil fields adjacent to some of these lines has caused them, to revert to coal. The change back to coal will be still more evident as the increasing prices for oil offset its advantages. The use of oil fuel in place of coal in Western Canada depends upon the low price of crude oil from California or from other States belonging on the Pacific and from Mexico. It is a significant fact that in 1915 the number of producing wells has increased, but the average yield per well per day dropped from 47 barrels in 1914 to 39 barrels in 1915. Although the petroleum business in California during 1915 was poor, and the price of oil H cents per barrel less, this has been due largely to the effects of the war. For the reasons given above, the price will increase, and there will be a greater demand for it for steamship use incident to the placing in full operation of the Panama Canal. The writer is of the opinion that, in so far as Canadian rail- ways are concerned, the economic advantages of fuel oil for locomotive use over that of Canadian coal are greater now than will be the case in the future. The Customs returns show the shipments of pig iron from the port of Middlesbrough during July to have amounted to 54,311 tons—1,835 tons coastwise, and 52,476 tons foreign— as compared with total clearances of 52,888 tons in June, 55,933 tens in July last year, and 81,687 tons in July 1914. Shipments to France reached 44,435 tons, as against 40,449 tons for the previous month. CONCRETE SHAFT EQUIPMENT.* By W. W. Lawrie and G. Hildick Smith. The concrete shaft equipment in the central shaft of the Bantjes Consolidated Mines consists of concrete shaft rail foundations as continuous stringers through the shaft, these stringers being a substitute for timber sills in inclined shafts. The shaft rails are laid and held in position on the stringers by holding-down bolts. The Bantjes Consolidated Mines central shaft is an inclined shaft, 33 ft. by 7 ft. 6 in., dipping at an angle of 34|deg. The position of the shaft in respect to the reefs varies, due to dykes and faulting. The distance between the South Reef and the Main Reef leader is 95 ft., measured at right angles to the angle of dip, which averages 35 degs. Throughout the whole length of the shaft such pillars have been left as to ensure no danger of movement in the shaft, not only of -the hanging wall, but also of the footwall, the latter being an essential point where concrete shaft-rail foundations are used. Dimensions of Concrete Stringers. Fig. 1 shows a cross section of the shaft. From this it will be seen that the rail gauge is 4ft. 2 in., the rails being of the ordinary 60 lb. type, the distance between the outer edges of the rail head and the top edges of the stringers is 4Jin. (not 5|in. as erroneously marked in fig. 2). The width across the top of the stringers, which carry two sets of rails being 2 ft. 9 in., the width of the outside stringers placed against -the side of the shaft varies according to the irregularities in the width of the shaft, making the average width of the out- side stringers 1ft. 6 in. The angle of batter of the sides of the stringers is 65 degs. The thickness of the stringers varies, due to irregularities of the footwall, the average thickness being 1 ft. 9in. Construction of the Stringers. To equip a section of the shaft with stringers, work is commenced from the bottom portion of the section to be built, and the concrete built upwards through -the shaft. Boxing, in lengths of 18 ft., is placed in the required position in the shaft and carefully laid to the correct grade, etc., and wood blocks to form the pigeon holes for the rail holding-down bolts are bolted to the boxing. These wooden blocks are slotted at the bottom edge, to allow for the iron bars a, fig. 2, 3 ft. long by 1| in. diameter, which are built into the concrete, and round which the hook holding-down bolts are placed as shown in fig. 2. Originally the holding-down bolts were placed 6 ft. apart. It is now found better to space them 4 ft. apart, thus the wooden blocks forming the pigeon-holes are placed 4 ft. apart on the boxing. When the length of boxing i-s in position, it is held by means of cross timbers, which in practice project beyond the sides of the boxes and are blocked up off the footwall of the shaft. A mixture of, roughly, six parts of unwashed develop- ment rock—quartzite or reef, not dyke matter—obtained from the most convenient point and having been passed through a screen of 2 in. square mesh, and one part of Pretoria Portland cement is shovelled into the box after a thorough mixing, with the necessary quantity of water, on a temporary staging, placed as near the box as possible. When the filling of the box is complete the box is lifted off the concrete, the concrete being levelled and smoothed over by hand with a trowel and the corners pointed up. If the section completed is the bottom section, and other sections have to be built above it, the box w7hen removed is placed above and against the new concrete, which -is allowed 12 hours to set, and the opera- tions repeated. Cost of Stringers. One white man and nine natives can build one 18 ft. section of concrete in one shift; thus for each stringer the cost per foot is :— "W ages— White.................. 1 at 22s. 6d. Native................. 9 at 2s. 9d. Total, 47s. 3d. per 18 ft. section. = ^S‘ ^>er Material.—Assuming that stringers 3-0 x 1’75 cross section are being built, then cubic foot of concrete per foot run = 3-0 x 1-75 = 5*25 cub ft. The theoretical 5’25 mixture being 6 to 1, = 0-75 cub. ft. of cement per foot of stringer, or 13-5 cub. ft. for a section of 18 ft. 13*5 Allowing 2’1 cub. ft. in one bag of cement, then - = Z' 1 6-4 bags of cement. In practice, due to spillage, etc., it is found that on an average 10 bags are required for an 18 ft. length of stringer, thus :— 10 at 6s. 6d. = 65s. = 3s. 7d. per foot. 18 The total labour and material costs per foot of single stringer is therefore 6s. 2|d. Thus for equipping the shaft complete with stringers, as shown in fig. 1, the * From the Journal of the Chemical. Metallurgical, and Mining Society of South Africa.