The Mechanical Handling and Storing of Material

TRANSPORTERS. BRIDGE OR CANTILEVER CRANES 443 end is lowered beneath the main structure into the position shown in dotted lines. This is accomplished by means of rope d. The rollers a, which are at the extremity of the jib end, move in the groove formed by two channel irons, which are bolted to the structure, the rope b remaining unaltered. This rope is guided in a similar manner to that shown in Fig. 609, but as this transporter works in conjunction with a two-rope grab, an additional rope is employed for the opening of the grab. Such installations are successfully at work on the Providence river, Indiana, U.S.A. Transporters Erected for Messrs Jones & Adams, West Superior, U.S.A.—This installation is illustrated in Figs. 622 and 623, which give plan and elevation of the crane; it consists of three Brown bridge tramway cranes, operated by electric power. The three transporters are shown running side by side on the same lines of rails, and are used for unloading coal from vessels and conveying it to stock piles or into railway trucks. At a recent test it was found that the capacity of three of these transporters was about 2,500 tons of coal in ten hours. The average capacity is, however, 60 tons per transporter per hour, or one trip per minute. Fig. 621. Transporter of the M'Myler Co. The grab used was of a capacity of 1 ton, and the test was made with Hocking coal, which is one of the most lumpy coals in the United States, and more resembles Scotch coal. When the test was made, every bucket of coal was carried from the front of the quay to a distance of about 150 ft. before the grab was allowed to discharge. The illustration renders a minute description unnecessary. The transporter is manipulated from a machinery house which has a driver’s cabin above, and can move backward and forward along the quay side over the three lines of rails shown. 7 he grab is lowered into the hold, and when full, raised again, and the coal or other material is brought over the stock pile or over railway trucks, where the grab is opened to discharge its load. The same installation can, of course, be used to take the material from the stock pile with the grab, and discharge it into either railway trucks, or into vessels at the quay side. This installation was erected by the Brown Hoisting Machinery Co. Bleichert’s Transporters.—The transporter illustrated in Fig. 624 consists essentially of a bridge girder b with two extensions a and a1, and two trestles p and s