The Works Of Messrs. Schneider And Co.

THE ROLLING- MILL DEPARTMENT. 89 weighing 35 to 38 tons, previous to welding, Its principal dimensions are : Hl. ft. in. Length of hearth 4.000 13 H Depth „ 3.400 11 2 Height under ai’ch 1.950 6 4^ Width of door 2.900 9 Height of door 1.450 4 9À Two grates 1.400 4 7i by .900 by 2 11* The doors of these furnaces are formed of iron frames lined with firebricks. The large doors are di vided in three parts, which can be lifted up together or separately, by means of chains, worked by hydraulic rams placed on the furnace fronts. The charging of the furnaces is effected with the C-apparatus already referred to ; it enables the charge to be taken up under its centre of gravity, not- withstanding the height of the furnace arch. The view, Fig. 210, page 86, shows one of these apparatus suspended to the overhead travellers serving one of the furnaces. The men can easily guide the apparatus and deposit the ingot on brick blocks in the furnace ; these Blocks insure a regulär heating of the whole ingot surface ; they vary in height and section with the weight of ingot to be carried. There are three sizes of these C transporters, namely, 5-ton, 15-ton, and 40-ton power, the weight of the latter being 20 tons. The part which carries the charge being liable to wear, it is made movable ; it is either flat or fork-shaped, according to the nature of the charges it has to take up. It is claimed that no beiter means of solving the difficulty of furnace-charging has been devised. The two furnaces which serve the blooming mill, and over which an overhead traveller also runs, are occa- sionally used for heating ingots rolled in the armour-plate mill. In this case the ingots are placed on the carrying rollers near the hot shears, which take them to the mill. Travelling Crânes.—When the plant was first put down, only the manufacture of thick merchant-plates was contemplated, and for this work an overhead traveller of 20 tons capacity was erected with a span of 19 metres (62 ft.), and a length of travel of 75 metres (246 ft.). But after Messrs. Schneider and Co. decided on the rolling of armour-plates up to 40-tons weight, this part of the plant becaine insufficient, and a traveller of 60 tons had to be added. For this, the carrying girders were strengthened to span the length of 35 metres (115 ft.) over the armour- plate mill, the girders being supported on extra pillars. Formerly the travellers were driven by a transmission shaft, but they are now worked by electric motors coupled to the original mechanism. The lifting speed of the load by the 20-ton traveller is 5 metres (16 ft. 4 in.) per minute for 8-ton weights, and 1.25 metres (4 ft. 11 in.) for loads up to 20 tons. The carrier travels 10 metres (32 ft. 9 in.) and the traveller 20 metres (65 ft. 7 in.) per minute. The speeds of the 60-ton traveller are about the same. Shearing Machines.—In the same axis as the armour- plate mil] and 26 metres (85 ft. 4 in.) distant, is a large hot shearing machine, worked by steam, to cut steel plates 1.20 metres (3 ft. 11 i in.) wide and .120 metre (4f in.) thick, or .700 by .200 metre (27-1% in- by 7-J in.), to préparé slabs for the other milis. A line of rollers unites this machine with the mill, and a series of rollers beyond the blades is added in a jointed frame which gives way under the pressure of the cut piece. The flywheel is fitted by a key which will break in case a piece unusually ré- sistant should come between the two jaws. The top blade holder is thrown in gear by a hydraulic ram. The steam engine driving these shears is of the following dimensions : Diameter of cylinder Stroke ... Revolutions per minute 0.550 in. 0.500 m. 168 in. 19} lin. 168 The intermediate toothed-wheel gearing has a ratio of 56 to 1, corresponding to three strokes of the tool per minute. This shearing machine is placed under the 15-ton electric travelling crâne referred to in the description of the blooming mill. Annealing.—All the steel merchant-plates are annealed separately before shearing; the furnaces in which this work is done is illustrated by Figs. 219 to 222, Plate XLII. The plate is deposited on the floor, and is brought to the furnace by tongs fitted on a rod, the whole being drawn by a chain hooked on a portable steam crâne. The plate slides on fire-brick supports as far as the opposite side of the furnace ; it is heated to a determined temperature, and is drawn out of the furnace from the rear. It is then left to cool clown on cooling beds. The furnace is 7.900 metres (25 ft. 11 in.) long, 3.100 metres (10 ft. 2 in.) wide; it is fired by four grates of the usual type, 1 metre by .7 metre (39| in. by 27^- in.), provided with a steam jet. The fiâmes di vide through openings, the position and size of which have been determined by experience, the outlet of the gases to the chimney, being near the furnace doors. There are two furnaces of this type. Sheet Mills.—As already stated, two processes are followed at Creusot for the manufacture of sheets. 1. By rolling out the slabs immediately after they have been cut hot. 2. By rolling out the slabs after these have been re- heated in horizontal furnaces. By the first process, biooms proportionate in weight and section to the slabs required, are taken from the shearing machine placed near the blooming mill already described. When a greater number of biooms are produced than can be dealt with in the sheet mill, the surplus is kept hot under a layer of ashes. The biooms are placed by means of trucks in two small reheating furnaces, fitted with one grate of the usual type, pro- vided with air biast ; the waste gases heat multitubular boilers of 135 square metres (1453.18 square feet) heating surface, of the same type as those already described. After