The Mechanical Handling and Storing of Material

252 THE MECHANICAL HANDLING OF MATERIAL a similar manner on the other side. With this arrangement the clip is attached to the rope and the truck hauled along until within a short distance of the cross-over. Here the clip is disconnected and attached to the rope outside the track to pass the cross- over, when the clip is again attached to the rope on the inside of the track. The power for driving this plant is supplied by a steam-driven winding engine and the rope is kept taut by a live tension weight. By a winding tackle this weight is kept in the position shown on drawing, at any point between the pier and water level. An interesting arrangement of canal haulage, for drawing boats through a tunnel, is shown in Figs. 363 and 364, although it does not come strictly under Endless Rope Haulage. By the system here employed, a rope, after passing the drum of the winding engine in the haulage boat, rests in the canal bed, the ends being connected with suitable anchorage, provided with tension gear to take up any slack. The winding gear in the haulage barge is electrically driven, the current being supplied from an accumulator boat which is drawn behind. When the motor is started the boat hauls itself along the fixed rope. With this installation a train of barges may at one time be drawn through the tunnel at a speed of from two to three miles per hour. As a typical example, the rope haulage plant erected by Georg Heckel, at the Röchling Iron and Steel Works at Völklingen, in the district of Saarbrücken, Germany, and illustrated in Figs. 365 and 366, may be mentioned. The arrange- ment there is as follows :— The railway commences in close proximity to the coal-washing plant, where the Fig. 358. “Jockey” Coupling below Truck. driving gear and the steam engine are also situated. There are two lines of rails, one of which is for loaded trucks and the other for empty ones on their return journey. The trucks or tubs are loaded from the bin a, which receives the washed coal. When full, they are run on to the right-hand track of rails, and the rope is pushed into a fork-shaped clip attached to the front of each tub (see Fig. 347). By the traction of the rope, the clip engages firmly as the fork turns on its axis and adjusts itself to the rope, and the truck is then carried along. 'The distance of travel is 264 ft., while the angles traversed are as much as 90°, and the inclines as much as 10°. After a sharp incline, the tubs turn round at the terminus b, and descend upon the second line. Before reaching the lower terminus the rope is so raised that it automatically disengages itself from the clips. The trucks discharge them- selves automatically. Fig. 368 represents one of the tubs, the two sides a, a being so hinged to the upper portion of the frame that the flap doors open outward. The bottom of the tub has a ridge in the middle and slopes from there towards the flap doors, thus ensuring a complete discharge of the tub when these doors are opened. Beneath the body of the truck is fitted a powerful spring which depresses the two levers b, and thus keeps the door closed. At the end of each of these levers b there is a latch which overlaps the side of the truck. Another lever c is fitted underneath the truck which carries at its end a roller. This is for the purpose of compressing the spring