The Mechanical Handling and Storing of Material

588 THE MECHANICAL HANDLING OF MATERIAL coal is elevated in this skip by a hydraulic jib crane, swung round over the hatch, lowered into the hold of the vessel, and there emptied. The crane is capable of travelling with its load along the quay wall, and is thus able to reach hatches at varying distances from the tip. With 10-ton wagons 293 tons of coal have been tipped on board a steamer with one crane in an hour. One crane is therefore capable of working at the rate of 30 skip- loads per hour. The actual working rate in practice is, however, lower than this, and the following record, published by the patentees, gives the time taken and the quantity of coal loaded with two cranes :— Name of Steamer. Quantity. Time. 'Pipping Operations per Hour with One Crane. Lancashire - Asama Knight Companion Runic Rhympha - Isle of Anglesea Inchlonga - - Orsino Nedgid Wingates - Tons. 5,817 5,833 6,41J 6,218 3,303 2,033 4,133 2,781 3,910 2,866 Hours. 20 30 34 28 16 13 27 12 13 11 Tips per Hour. 14-5 9-7 9-4 11 *0 10-3 7'8 7-7 11-3 15-0 13-0 Average, I1-0 A case may be mentioned of a steamer which went into berth at 5 p.m., and by 5.30 next morning had taken in 1,609 tons of coal, an average, after deducting stoppages, of 189 tons per hour, so that in this case 1,609 tons were shipped by one crane in eight and a half hours. The net loading time, after deducting delays, incurred in waiting for coal of the S.S. “Samoa” was twenty-eight hours, in which time she took in 7,484 tons of cargo and 1,750 tons of bunkers, or an average of 330 tons per hour. The S.S. “ Iran,” which was loaded by four cranes, took on board 9,213 tons of coal in a net loading time of twenty-six and a half hours, or on an average 347 tons per hour. This system is the invention of Sir William T. Lewis (general manager) and Mr Charles Hunter (engineer) of the Bute Docks, Cardiff, and has been adopted by the Cardiff Railway at their Roath Dock, Cardiff. Tips similar to the foregoing, in which the railway truck is emptied into ordinary and mechanical skips holding the full contents of the truck, which are then emptied into the ship’s hold, have been designed by Mr G. T. Wart, colliery manager of the East India Railway; also by the Wellman-Seaver-Morgan Engineering Co., Ltd., Cleveland, Ohio. Besides these may be mentioned the Butler and Fielding system.1 Other noteworthy devices are intermittent appliances in which the contents of the truck are emptied, either on or below the level of the rails, into a hopper from which they are transferred by a smaller skip to the ship, and then lowered into the hold. Good examples of this type of tip are those erected in 1893 for the East India Railway ; also the one erected at the Kidderpur Dock, Calcutta, both by Sir W. G. Armstrong, Whitworth, & Co., Ltd. In the latter instance each skip holds one half of a wagon load, or about 5 tons. The Rapier Coaling Crane may also be mentioned, as well as the Beckett system, which is the invention of Mr W. T. C. Beckett, deputy agent and chief engineer, Bengal-Nagpur Railway, as they also belong to this type of coal tip. 1 This system was fully described in the Engineer of 2nd June 1893.