December 17, 1915. THE COLLIERY GUARDIAN. 1235 The “ Diamond ” Coal Cutting and Conveying Machines. By T. CAMPBELL FUTERS, M.I.M.E. (Continued from page 1198.) vastly superior, by a chain working on machine-cut gearing. The conveyor belt is of the canvas or balata type, passing over a patented compound system of small driving pulleys, which prevents slipping; and guide plates are fitted to each side to keep the coal from spilling. Figs. 14a and 14b illustrate the small “ chain ” type longwall coal cutter, already described (Colliery Guardian, December 3, 1915, p. 1131), and show clearly the distinctly novel features of the worm drive for the cutter chains, and the arrangement for swinging the jib by means of the rope and chain from the feed of the seam in the gateway, or, as commonly expressed, “ to take up the bottom,” the Diamond Coal Cutter Company Limited have introduced a gate end conveyor, or elevator. This we are now enabled to illustrate in figs. 21a and 21b. It consists of a steel framework, easily taken apart for removal in sections from one Erratum,—In the article on “ The Diamond Coal Cutting and Conveying Machines,” two errors in dimensions occur, viz., Colliery Guardian, November 26, first page, second column, 10| in. should be 16| in.; and third column, fourth line, 2 ft. 6 in. should be 3 ft. 6 in. Fig. 14 a. |o Fig. 14b. Figs. 14a and 14b.—“Diamond” Chain Type Worm-driven Longwall Coal-cutter. Ack \ 1 o°d' Io'-"-- '-'oi h—Pi H IH TRAINING OF COLLIERY MANAGERS* By Noah T. Williams, B.Sc. A generation ago coal mining was a very simple industry, but to-day it is a very complex and diversified industry, and it is constantly extending its boundaries. Machinery is now applied extensively, and the demand for higher efficiency has increased, owing to greater competition, which necessitates the adoption of all legitimate means of keeping the cost of production as low as possible. Moreover, thinner and poorer seams have to be developed. It is obvious that the conditions have altered, and we must be prepared to meet them, by attaining a higher standard of education. There is no reason why educa- tion should not be raised in this country to the level which it has already long since attained in other great countries which are our competitors. If the object is to be attained, it will be necessary to be constantly in touch with those who are associated with the practice of the mining industry. I have no doubt that this branch of the Colliery Managers’ Association will give this question their sympathy and active co-operation, for I believe none would more readily admit the need for better scientific training than the colliery manager, to whom we are indebted for many of the advances made, and none are better aware of the enormous waste resulting from ignorance. For the year 1913 there were about 2,500 managers in control of collieries in this country, and the total output for the same period was over 287 million tons. If we assume an average working life of 20 years, it is plain that to keep up the supply of 2,500 managers there will be required annually 125. Since the establishment of a Central Board of Mining Examinations by the Act of 1911, the number passing the examinations is extremely out of proportion to the demand. The results are as follow :—For November 1912 and May 1913, 65 successful; for November 1913 and May 1914, 90 successful. Allowances must also be made on account of the unsuitability of some candidates to take charge of a .colliery; others again may never enter upon the duties of a colliery manager. The “ pit mouth ” value of coal produced in 1913 was over £145,000,000; therefore, each colliery manager superintended and controlled an average value of £58,000. From these figures, it seemed an important matter to the nation that colliery managers should be thoroughly trained to their business. Our national prosperity is absolutely dependent on our attaining the very highest level of efficiency. Surely, then, it would not be a bad investment for the State to spend a portion, Fig. 21a. Tifil i j Fig. 21b. Figs. 21a and 21b.—“Diamond” “Gate-end” Elevator or Conveyor. drum. The dog clutch for disconnecting the cutter chain from the motor is also clearly shown, as likewise the worm drive for the “feed.” The chief advantage of the worm drive lies, of course, in the absence of noise, and altogether there seems much in this machine to recommend it to those about to instal coal-cutting machinery. In our last issue we mentioned that, to overcome the difficulty of having to lower the floor below the level point to another, and re-erected afterwards. The load- ing end of the conveyor is mounted on wheels which run on rails, whilst the front or “ face ” end rests on the floor, and is secured by means of a small jack. It may be driven by either an electric or compressed-air motor; that shown in the illustration being of the latter type, and compactly situated below the inclined portion of the conveyor. The driving gear from the motor may be either by sprocket chains, or, which is at any rate, of the required sum of £60 a year in educating a man for three academic years, inasmuch as the manager will have direct control of an average production of £1,060,000 as the result of the work directed by him during his working life of 20 years. When we consider the net profit possible, and not the gross output, and when we consider the nature of mining * Paper read before the Lancashire branch of the Colliery Managers’ Association, December 11.