The Mechanical Handling and Storing of Material

6oo THE MECHANICAL HANDLING OE MATERIAL or if anything the advantage will be with the loader, as the emptying of a shallow skip should injure the coal less than that out of a rectangular truck, because there is less drop and the thickness of the layer of coal is likewise less. Be this as it may, the greater part of the breakage caused in the transferring of the coal from the railway trucks to the skips will be additional, as we may be justified in making an allowance for a little less breakage at the top of the loader. Now, this may be a serious matter if tender coal has to be handled, and yet with some coal it may be of so little consequence that the first named advantages of the loader more than balance the extra breakage. Ihe port of Miike, at which the above described coal-loading installations are now at work, is the most important centre of the Japanese coal industry. These devices deserve special attention, as they differ so much from the appliances generally used either in this country or in Europe or America. The colliery of Miike, the property of the Mitsui Mining Co., is the most important in Japan, with a daily output of 5,000 tons; and as the old harbour was only Fig. 845. View of Port Miike Loaders during Erection. accessible to sailing ships, the company extended and modernised the harbour at a cost of 5,000,000 yen, oi over half a million sterling, so that now large steamers can load there, whereas of old the coal had to be transhipped at Kuschinotzu, a distance of over 50 miles, from sailing ships to steamers. The general scheme is the design of Director Dan, and chief engineer Kuroda, of the Mitsui Colliery Co., and the loaders were built by Head, Wrightson, & Co., Ltd. The Wrightson Coal Shipper.1—Ihe illustration, Fig. 846, represents a device ■erected at the staiths of the Cramlington Coal Co., in the Northumberland Dock on the Tyne. It was designed by Sir Thomas Wrightson, M.Inst.C.E., in conjunction with Mr Morrison, manager of the Cramlington Co., and was erected by Messrs Head, Wrightson, & Co., Ltd., of Stockton-on-Tees. The coal is in this case brought in at a high level and discharged into the hopper immediately above the level of the first conveyor. At the lower end of the hopper a door of sufficiently large dimensions to allow the largest pieces of coal to pass, permits 1 The Engineer, 6th and 13th August 1897 ; and Iron and Coal Traded Review, 3rd May 1901.