The Works Of Messrs. Schneider And Co.

X.—THE SIEMENS-MARTIN PLANT. Furnaces and Casting Pits.—The Siemens-Martin plant was commenced in 1873, with six 8-ton furnaces ; these were placed in a building 94 metres (308 ft.) long ; 54 metres (177 ft.) wide ; and 9 metres (29 ft.) high. In 1874 the furnaces were enlarged to a capacity of 12 tons. They were again increased to 15 tons capacity in 1876, and to 20 tons in 1888. These furnaces were con- structed on two parallel lines, and in two groups of four and two, level with the ground. Each furnace was supplemented by an adjacent gas-heating furnace, in which the metal to be melted down, was previously brought to a red heat. They were also provided in every case with a revolving platform 8 metres (26 ft.) in diameter, mounted on a hydraulic ram. The ingot inoulds were arranged around the outer edge of tbis platform, and were brought successively under the casting channel. The removal of the ingots was effected by means of 2-ton hydraulic crânes. In 1877 a rectangular casting pit was made in the axis of the building, beyond the space occupied by the two lines of furnaces already described. The special purpose of this pit was to facilitate the casting of large ingots required in the manufacture of heavy forgings. It was served by a revolving steam crane of 80 tons, which has lifted on several occasions pieces weighing more than 100 tons. The dimensions of the casting pit were as follow : m. ft. in. Length 16.000 52 0 Width 3.700 12 2 Depth 5.500 18 0 The depth of 18 ft. was, however, increased to 9.500 metres (31 ft. 2 in.) over a part of the length, to facilitate the production of very heavy ingots. In 1878 such an ingot, weighing 120 tons, was cast in this pit ; a full-sized model of it was exhibited at the Paris Exhibition of that year (Fig 82). When casting ingots in the pit, the ladies carried on bogie trucks, were brought under the casting runner of each i furnace by means of the turning platform above referred to. Two main tracks, one on each side of the casting pit, j parallel to the furnaces and in communication with the j revolving platforms, served by means of turn tables, for 1 conveying the ladle to the casting pit. Movable tracks were laid over the pit, in such a way as to be easily j adjusted with the turntables of the main tracks. By this | arrangement it became easy to bring the ladies direct over the ingot inoulds. The tracks on the pit permitted, by means of suitable runners, the discharge of four ladies j simultaneously into one mould. Notwithstanding the comparatively small dimensions of this pit, it sufficed for a period of seventeen years, during which time no less than 170,210 tons of large ingots for armour-plates, guns, and shafts, were produced. A seventh Siemens-Martin furnace, of 20 tons capacity, was built in 1878. In 1892 Messrs. Schneider and Co., finding it an urgent necessity to increase the size of their steel plant, built an eiglith furnace, the capacity of which was 25 tons. A new casting pit was also made parallel to this furnace. Since 1892 considérable developments have taken place. The increasing demand for steel, due to the growing manufacture of armour-plates, guns, special Fig. 82. 120-ton Steel Ingot cast in 1878, forgings, &c., made it a necessity in 1893 to construct a casting pit much larger than the one already described for the production of still heavier ingots. Figs. 83 and 84 are views of this pit, which is made in a building 25 metres (82 ft.) wide; 54 metres (177 ft.) long; and 14 metres (46 ft.) high, to the springing of the roof ; it is placed in a line with that containing the Siemens-Martin furnaces. The plan, Fig. 77, Plate XVIII., clearly shows the position of the different Siemens-Martin furnaces and casting pits. An electrically-driven overhead travelling crane, built by Messrs. Schneider and Co., with a capacity of 150 tons lifting power (to be described later), and