The Works Of Messrs. Schneider And Co.

ARMOUR-PLATE FINISHING SHOP. 69 tool carrying slides. Total weight of the lathe 250 tons (see Fig. 155, Plate XXXII.). There is one boring machine, with an hydraulic feed device, to bore out ingots for the manufacture of hollow forgings. The ingot is fixed in a revolving jacket, placed on the middle of the length of the frame. Boring is carried on at both ends simultaneously by means of two boring bars, which are kept at a regulär feed by two hydraulic rams. These bars are of two kinds, one boring out a central core, the other clearing out the central part (Fig. 156, Plate XXXII.). Some spécifications require that the core be inspected, in order to ascertain that the ingot does not contain any internal flaws. r'fl.-esd-ijw 1________1.600 i / 16b I k^- Diameter of largest ingots bored... Length ... ... Diameter of usual bore m. 1.400 6.000 0.400 ft. in. 4 7 19 8 1 4 Ingots can be finish-bored up to .800 metre diameter (2 ft. 71 in.). Another powerful lathe is used for cutting up very large ingots, and to rough-turn heavy forgings. It can work pieces weighing up to 100 tons. IH. ft. in. Length of bed 17.500 57 5 Height of centres ... 1.500 4 11 Length between oentres ... 16.700 54 9 Diameter of faceplate 3.000 9 10 There are four tool-holders, two on each side. The total weight of this lathe is 312 tons. Near these lathes is a powerful vertical finish-boring machine, placed in a pit, and which is used for finishing the inside surfaces of turret armour. It can treat cylindrical or conical turrets 5 metres (16 ft. 6 in.) in diameter and 6.600 metres (21 ft. 8 in.) high. Each one of these machine tools is driven by a separate dynamo. The pieces are lifted in and out of place by the two travellers of 40 and 80 tons already described. Armour-Plate Finishing Shop (Fig. 157).— As a rule, the armour-plates on leaving the steam hammer or the rolling mili, are moulded to shape and then cut to size. The cutting is done by circular saws of a special type designed and manufacturée! by Messrs. Schneider and Co. The plate is fixed, while the saw travels forward. These machines are of two sizes. The largest-sized machine (Figs. 158, 159) for finishing thick plates, consists of a low frame 11 metres (36 ft.) long ; 2.300 metres (7 ft. 6| in.) wide ; and of a slide on which are mounted two headstocks, one carrying a shaft, at one end of which is fixed the circular saw, a large toothed wheel gearing in a screw being fixed at the other end. A shaft runs the whole length of the machine, and is set in motion by a transmission fitted on the end of the frame. The driving screw which sets the toothed wheel in motion is placed in a casing that forms one piece with the headstock on that side, and travels forward with it. The shaft is formed with a groove on its whole length, in which slides a screw key. The headstock on the side of the saw is made to slide crosswise, to facilitate the régula- tion of the cut. When the plate has been put in place and strongly bolted down, the line of cut being parallel to the machine frame, the saw is made to advance in place exaetly opposite the line of cut. This is easily determined, as the shaft on which the saw is fixed, can move to-and-fro in the toothed wheel on the opposite side. The saw is a hard-steel disc 22 millimétrés in.) thick, with 76 tool-sockets 24 millimétrés in.) wide, and 70 millimétrés (2f in.) deep arounel its periphery; these sockets contain an equal number of cutters, half of which are 25 millimétrés (1 in. bare) wide, the other half being