228 THE COLLIERY GUARDIAN. February 1, 1918. beams. The columns have two slots on each side for the purpose of spacing the wall slabs. The building was erected very much in the same manner as is followed in the erection of a structural steel building. Walls of the building are two slabs carried in the column slots, and are 3 ft. wide and in. thick. They are ribbed on the edge and at cross intervals, and are reinforced with triangular mesh. These slabs are spaced approximately 6 in. apart, and the space between filled with mineral wool for insu- lation. In the centre of the building is a two-storey part for the purpose of housing the blowers and heaters. Steam is furnished by a special boiler plant about 300 ft. away. The boiler plant consists of four 500 horse-power Sterling boilers equipped with stokers, and, besides furnishing steam for this plant, also takes care of the plant built in 1911. There are three blower units, one for each room. These are of the double-discharge, blow-through type, and each blower delivers 103,000 cu. ft. of air per minute at 250 degs. Fahr, from the heater. The duct system is arranged so that hot air can be delivered to any room or to any combination of the three rooms with any number of the blowers in operation. Under normal operating conditions, however, each blower unit serves its own thawing room. Two hot air ducts extend from the blower room to each end of each thawing room, and are between the ceiling and roof above the corners of the rooms. Hot air is blown through these ducts and into downwardly extending flues on the walls. Part of these flues are carried below grade, and have openings at the centre of the track, while alternate flues open toward the sides of the cars. This arrangement gives a very uniform distribution of hot air. Above the ceiling and between the hot air ducts is the return air duct. Air from the thawing room is admitted to the return duct at intervals, and is returned to the blowers to be re-heated, and again blown into the thawing rooms. A temperature of about 200 degs. Fahr, is attained in the room, and with this temperature badly frozen coal is thawed in from one to two hours. It is not necessary to thaw the coal all the way through, but only to a distance from the bottom and sides of the car sufficiently to allow all the coal to leave the car when the car is turned over by the dumpers. When the coal is thus thawed, the ice throughout the body of the coal is usually rotted sufficiently to cause the coal to break when it is dumped into the pan. Construction of a plant of this kind is expensive, when it is considered that the plant is in operation only about 90 days during the year. It is, however, fully as important to provide for rapid shipment of coal during the winter months as in the summer time, when ship- ment is carried on tide water. The designing and construction of the plants was carried out by the Walter S. Newhall Company, of Cleveland, Ohio. MR. J. FOX TALLIS. The new president of the South Wales Institute of Engineers, Mr. J. Fox Tallis, Llantarnam Grange, has been a prominent mining engineer in South Wales for many years. He was articled to the late Lord Merthyr in 1870, and in 1875 entered the service of the Ocean Collieries Company as assistant to Mr. William Jenkins, with whom he remained for 18 years. He established the first Volunteer Corps in the Rhondda Valley in 1880, and resigned his commission as captain commanding the Pentre detachment on his leaving the district in 1892. In 1892 he was appointed general colliery manager to the Ebbw Vale Steel, Iron and Coal Company, which position he held for 18 years, retiring in 1910 to start private practice. In 1893 he was appointed one of the examiners for colliery managers’ certificates for the South-West District of England. Mr. Fox Tallis became a member of the South Wales Institute of Engineers as far back as 1885. In 1899 he was appointed president of the Monmouthshire Colliery Officials’ Association, and in 1908 chairman of the Monmouthshire and South Wales Coal Owners’ Asso- ciation. For a number of years he was a member of the Conciliation Board. Miners and Food Rationing.—The South Wales Miners’ Federation, at a conference at Cardiff . on Monday, demanded equality of distribution and a national ration- ing system; further, that local Food Committees be empowered to commandeer all supplies, including game and fish, and that local Food Committees should include Labour representation to the extent of 50 per cent, of the total strength of the committee. Mr. H. Smith presided, on Monday, at a meeting of the council of the Yorkshire Miners’ Association at Barnsley. He said, in regard to food, the workmen were determined to have fair play. The council were appealing to the men not to take any rash action, and they were anxious that peace as far as possible should be maintained, and that all assistance should be given to help to get over the serious crisis. They appealed to the Government to deal with the questions raised in a manner fair to the workers. Steel Trade and Employment Exchanges.—The Minister of Labour has appointed the following to be the Iron and Steel and Kindred Trades Central Advisory Committee (Employers), to advise and assist the Ministry of Labour on questions arising in the administration of the Employ- ment Exchanges which affect employers in that industry:— Mr. George Ainsworth, Steel Ingot Makers’ Association; Mr. J. J. Burton, Cleveland Iron Masters’ Association; Mr. Laurence Ennis, North of England Iron and Steel Manufacturers’ Association; Mr. F. W. Gilbertson, South Wales Siemens Steel Association; Mr. F. W. Gibbins, Welsh Plate and Sheet Manufacturers’ Association; Mr. John Graham, West Coast Iron Masters’ Association; Mr. J. B. Harding, North Staffordshire Iron Masters’ Associa- tion; Mr. George Macpherson, South Staffordshire Iron Masters’ Association; Mr. Frederick Mills, South Wales Iron and Steel Makers’ Association; and Mr. M. L. Simpson, Scottish Steel Makers’ Wages Association. Mr. J. J. Burton has been elected chairman. CHOOSING AND LAYING PIT RAILS.* The most important factors influencing regularity of haulage are the tubs and the rails, and no re-arrange- ment of the division of work or change in the type of haulage—for instance, from horse to mechanical trac- tion—can obviate defects arising from badly designed or constructed tubs, or the use of unsuitable rails and methods of laying them. Theoretical and practical considerations favour the use of a hopper tub, with a cubical content of not more than 35 cu. ft., so as not to overtax the putters, 32 in. being found the most suitable width for all conditions underground. The width of the tubs bears a close relation to the rail gauge. The broader the gauge, the easier the running; but the greater the difficulty in negotiating curves, so that wider roads are needed. In the Ruhr district, 22 to 24 in. is the regular gauge; but the extension of locomotive haulage and the resulting increased speed render a wider gauge advisable—the more so because the locomotives are often considerably wider than the tubs. Consequently, the width of the tubs can be conveniently increased to 32 in., and the rail gauge to 26 to 28 in. In main roads, the curve radius depends less on the haulage speed and centri- fugal force or the rail gauge than on the length of the locomotive. Rails. For reliability in working, the selection of the rails is more important than the rail gauge and the avoid- ance of sharp curves. No portion of the haulage equipment has had to meet such continually increasing requirements — through the extension of mechanical traction—as the rail; and only the best is good enough. Steel rails are used almost exclusively, of large and Fig. 5.—Plan. — / <7 -Li i I I I 1 ill iiiiL T_o_ Fig. 6.—Elevation. Figs. 5 and 6.—Peisen Turntable. Fig. 1.—Plan. Fig. 2.—Elevation. Figs. 1 and 2.—Rail Chair with Flexible Cheeks. Fig. 3.—Fishplate Joints. w 151 nsii U - - Q Fig. 4.—Staggered Joints. heavy section, the importance of which in connection with reliability is becoming more and more recognised. Whereas Demanet in 1905 still mentioned rails weigh- ing 6 to 12 kilogs. per running metre, the heaviest rails among the standard types laid down by the Asso- ciation for Mining Interests in the Dortmund district in 1911, was 20 kilogs.; and since that time still heavier rails have come into use. The greater the importance of a haulage road, and therefore the increased loss of output that can arise from stoppages due to de-railing, the heavier should be the rails, and the more should the principle be adopted of reducing running costs and loss of output by a heavier initial outlay. For example, Heise and Herbst, in their work on mining, estimate the annual extra charges for interest and depreciation on 1,500 m. of haulage road, for a pit winding 2,000 tons per diem, as 16,600 mk., in consequence of the laying-out and maintenance of the track in a suitable manner; but, on the other hand, they put the reduc- tion in running costs at 5,900 mk. Sleepers, The stamped iron sleepers now largely used for sur- face tracks are only suitable to a limited extent for underground work, owing to their liability to rust, low resistance to acid pit water, and the tendency to spread due to their being frequently laid on the sur- face of the track ballast. In dry mechanical haulage roads, where rock, pressure is small, iron sleepers are superior to wooden ones, the working life being longer, and the height smaller. Consequently, pit rails are, for the most part, laid on wooden sleepers, which must be strong enough to give a permanently firm hold on the spikes or bolts with which the rails are secured. A thorough impregnation is desirable wherever the sleepers are exposed to alternations of wet and dryness. For main roads and inclines, hewn oak sleepers are generally employed, whilst beech or pine logs, simply dressed flat top and bottom, to fit the floor and rail feet, suffice for branch roads. Nevertheless, for sleepers situated under rail joints, oak or beech is also advisable even in the gate roads. Mounting Rails. In the case of iron sleepers, the rail connection frequently consists of cast-on or riveted chairs or * Gliickauf. claws, which grip the rail foot—or else of loose chairs and bolts. The permanently fixed supports have the disadvantage that the rusting of the iron gradually loosens the connection, and allows the rails to oscillate. This drawback can be remedied by the use of bolts and nuts, but even the bolts work loose, unless special lock- ing devices are provided. In the case of wooden sleepers, the usual rail fasten- ing is the dog spike; but, although spikes or clamp- ing plates are sufficient in gate roads, they will not do for main roads when mechanical haulage, or even horse traffic, is in question, insecure fastenings result- ing in mechanical injury to those portions of the sleeper that are in contact with the rails, and shorten- ing the life of the sleepers even more than decay. A good fastening for rails on wooden sleepers should comply with the following requirements: — (1) It should hold the foot of the rail, not by means of spikes or clamps, which soon work loose, but by wood screws or through bolts. (2) It must provide for the consequences of the gradual rusting away of the rail foot and the iron connections, and therefore must be capable of being tightened up. (3) The mechanical destruction of the sleeper under the rail foot must be prevented by the inter- position of a plate to distribute the rail shocks over a larger area. (4) The method of attachment must be quick and secure, keeping the rails true to gauge, and prevent- ing tilting. (5) Low prime and upkeep costs are essential. A. number of such rail fastenings have been intro- duced from time to time, among them being the Korn- feld system, in which the rails are held on both sides Fig. 7.—Peisen Turntable for Double Tracks. by fishplates, which engage with the top of the rail foot, and are bolted to the sleeper, the lateral thrust on the bolts being taken up by sharp-edged rings, which are cast on the under-side of the fishplates, and bit into the wood. The Brockhaus rail fastening is illustrated in figs. 1 and 2. The rail a is laid on a strong plate 5, cut and stamped so as to form the upwardly projecting cheeks c, which are somewhat higher than the top of the rail foot. These cheeks form a flexible bearing for the screws d, by virtue of which the screws can be tightened up as required, the live counter-pressure preventing the screws from working loose. This method of cutting the plate, to allow the cheeks to project, is better than merely producing raised cheeks by bending over, because in the latter case the springiness of the pro- jecting cheek is lacking—at all events, as soon as the bent over portion comes in contact with the body of the plate. The Brockhaus device has been found effective in railway work, where ordinary fastenings last only a short time. On one sharp curve, the fastening has been in use for 18 months without any of the screws working loose, though previously the screws began to loosen in a very short time. Laying the Rails. Even the best of rails, however, will not meet the requirements of the work properly unless well laid. In driving the roads in the first place, careful and syste- matic procedure will do much to ensuring the con- tinuity of subsequent haulage. The road grade should be uniform, and the accumulation of water, which, being more or less acid, will favour rusting, must be prevented at all cost. A gradient of equal resistance should be selected—that is to say, a gradient which will give an equal haulage resistance in the case of the empty and full tubs respectively on the out and in journeys — unless special circumstances, such as the haulage of a large amount of packing material from the shaft inbye—have to be taken into consideration. The joining of two rail ends together is effected by means of fishplates, or by simply butting the ends together over a sleeper. The former is the best for main roads, especially when the traffic is heavy—pack- ing material in particular, which pits a considerable strain on the track. To lessen jolting, fishplate joints should not be directly over a sleeper (fig. 3), otherwise any irregu-