Engineering Wonders of the World
Volume III

268 ENGINEERING WONDERS OF THE WORLD. TWO 15-TON ROLLING OPEN HEARTH FURNACES AT HAMILTON, U.S.A. The nearer furnace is in the tilted position which delivers the charge to the ladle seen commanding two rows of ingot moulds. employed, so that the breaking of one rope may not mean the fall of the load and the disastrous consequences attending the fracture or sudden emptying of a ladle con- taining sixty tons of molten steel. All the machinery is protected from the terrific heat by baffle-plates, and the operator’s cage is screened by similar plates and very thick glass. Steel intended for rolling into plates, joists, and angle bars is cast in iron moulds to form ingots. The heat so warps the moulds and Ingot Extract- ing Machines. roughens their interiors that the removal of an ingot be- comes a task requiring the services of special hydraulic or electric ma- chines able to exert a pressure of over 200 tons on the head of the ingot. Probably the most interesting appliance to be found in a casting- shop is a machine which removes the ingots from the moulds, and also places them in vertical soaking-pits or underground fur- naces, by which they are kept red-hot until needed for the rolling-mill. These machines consist of a pair of girders mounted upon end trucks like an ordinary overhead crane. Here the similarity ends, the trolley having a braced steel guide-frame depending from it, in which slides a steel mast having at its lower ex- tremity a pair of dogs or grippers. Five dis- tinct motions are given to the dogs, which can handle the ingot or mould almost like a pair of hands. It is perhaps needless to add that machines of this type are operated elec- trically. The operator rides in a cab built out from the hanging framework, and so is able to watch his load and see right down into the soaking-pits. The travelling speed is