Phần cho thấy một tời hệ thống dây cáp cho cần cẩu container và một cho unloaders lấy với một xe đẩy chính và phụ trợ. Đối với cần trục quay chứa thêm dây hệ thống cáp cho các dây cáp cẩu được sử dụng. Hình cho một sơ đồ của một hệ thống tời dây cáp khá phổ biến trong các container được treo vào ngày 12 rơi xuống thay vì 8 giảm khi hiển thị trong mục . | Chapter 6 Sagging and Slapping of the Wire Ropes Rock and ROll of the Spreader Machinery Trolleys versus Wire Rope Trolleys Twin-lift Positioning Automatic Equipment Identification AEI Sagging and slapping of the wire ropes other hoist wire rope systems for container quay cranes and grab unloaders Section showed one hoist wire rope system for container cranes and one for grab unloaders with a main- and auxiliary trolley. For container quay cranes further wire rope systems for the hoisting wire ropes are used. Figure gives a schematic diagram of a rather common hoist wire rope system in which the container is hanging on 12 falls instead of 8 falls as shown in Section . Figure shows two auxiliary trolleys which run at half the speed of the main trolley. These auxiliary trolleys are intended to decrease the sagging and slapping of the hoist and trolley wire ropes. The higher the hoist and trolley speeds are and the longer the trolley travel range is the more the sagging and slapping of the wire ropes will influence the throughput of the crane. A very good system is shown in Fig. with fully supported hoist- and trolley wire ropes which gives the best possible protection against their sagging and slapping in all circumstances. 156 Cranes-Design Practice and Maintenance Fig. Headblock hanging on 12 wire rope falls Fig. Wire rope support with two catenary trolleys Grab unloaders The same parameters and considerations apply to grab unloaders as to container quay cranes. The weights of the trolleys of grab unloaders vary widely they can be quite heavy. Sagging Rock and Roll Positioning and AEI 157 Fig. Fully supported wire ropes When the hoisting machinery is installed on the trolley itself it is possible to give the grab a cross-traversing. The unloader with main-and auxiliary trolley see Fig. has all the advantages of rope trolleys. Because of the presence of the auxiliary trolley the free hanging Fig. Rope .
