degree of homogeneity of outer and inner portions, and of bottom and upper sections. Crystallisation is larger in the portions that cool last. Moreover the top of the ingot becomes drawn downwards-piping, and the occluded gases produce more or less of honeycombing about the upper portions. Hence two methods are in use to lessen these evils;

Ingot Charging Machines. The general designs of furnace charging machines are described under Charging Machines. The present article relates to a type used for vertical heating furnaces or "soaking pits" which are usually situated below the level of the floor. Fig. 4 illustrates an overhead travelling crane type, electrically driven, with the following important additions to enable it to serve soaking pits. From the crab or trolley is suspended a rigid guide, within which a vertical tube carrying at its lower end a pair of tongs is free to slide up and down. These tongs are of special design, steadied by the

PLAN OF FOUNDATION

the casting with a head, to be cut off subsequently, and the fluid compression system. Ingots are made square rather than cylindrical in section to favour the equalisation of temperature, because that form will be drawn inwards by shrinkage, and relieve the strains better than a circular form will do.

Fig. 6.-5-Ton Ingot Crane.

guides, and can be lowered by the operator into exact position for picking up an ingot in the furnace without any assistance from men on the floor level, and removing it to any required situation. The operator's cage is also generally suspended from the trolley framework, as shown, so that he may always have a good view of his work.

The ingots are handled in a vertical position, being lifted from cars by the gripper, and deposited vertically in the soaking pits. After withdrawal from the pits the crane deposits them on a suitable ingot tilting car for transference to the tables which deliver them to the rolling mill.

In Fig. 4, A is the hoisting motor, в the slewing ditto, c is the cross traverse motor, and D the motor for operating the tongs, E is the balance weight, F is a casting that forms the bottom guide for the charging bar, and for carrying the turning gear; G is a casting forming the top guide for the charging bar, and

carrying pulleys for the hoisting ropes. The span of the traveller is 35 ft., and the trolley gauge 8 ft. 4 in. It was made by the WellmanSeaver-Morgan Co., Ltd.

Ingot Crane. A crane designed specially for, or adapted to the work of ingot stripping. The original type is a direct-acting hydraulic jib crane, see Fig. 205, Plate XV., in Vol. V.; the height of lift being equal to the lift of the ram. These cranes are either independent on a foundation, or top-supported. Another design is that shown by Fig. 5, Plate I., a five-ton crane made by Musgrave Bros., of Leeds, for the Frodingham Iron and Steel Co., Ltd., and in elevation by Fig. 6 adjacent.

It

a top-supported crane, the journal being seen at the top of the mast. The jib is a rigid one, sustained by two sets of tie rods. Five hydraulic cylinders are required for its operation; two, a for turning or slewing; one, в for racking outwards; one, c ditto inwards; one, for lifting, placed between the two channel sections of which the mast is built. Taking these in order :-The ram of A in moving downwards extends the chain anchored at a, and turns the chain wheel D at the foot of the mast in one direction; and a duplicate cylinder in line with it is for turning in the opposite direction. The cage for operating the levers for these, as well as the other cylinders, is seen at F; the levers themselves may be observed in the photo, Fig. 5, Plate I. The racking cylinder B, the reference letter being placed on its top pulley, moves the rope b passing round the guide pulley E at the end of the jib, and anchored to the outer end of the jenny or racking carriage F, for drawing the carriage away from the post. The rope c from the cylinder c is attached to the inner end of the carriage for drawing it towards the post. The extreme direction of the jenny in this direction is indicated at L. The lifting cylinder D has its rope anchored at d at one end, and at e at the other. The rope ƒ passes round a guide pulley at g over one of the guide pulleys J in the carriage, down over the snatch block pulley K, up over the second pulley J to its anchorage at e. The effect of thrusting the ram of D outwards is to raise the load. To lower, the pressure water is shut off, the escape valve

opened, and the load then descending by gravity pushes the ram back into its cylinder. The whole weight of the crane is taken on ball bearings, and the hook is also fitted with a ball race.

Ingot Iron. A term once used more than at present, to denote the milder qualities of open-hearth steel, or those very low in

carbon.

Ingot Mould.-A mould of cast iron for pouring steel into. It is of grey hæmatite pig, of various sectional shapes, but mostly square or rectangular, with enough taper lengthwise to permit of stripping, or lifting it off the ingot, for which eyes are provided. Ingot moulds are generally poured or teemed from the top, resting on thick cast-iron bottom plates. They endure from 50 to 100 castings. Fig. 7 shows a mould by the North-Eastern Steel Co., Ltd.

Ingot Saw.-See Hot Iron Saw.

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Ingot Stripping.-Drawing ingot moulds from steel ingots. The soaking pits are usually below the floor level, and served by specially designed cranes or charging machines. The ingot strippers are constructed on the general lines of an overhead elec- 2.2 tric travelling crane, like that in Fig. 4, page 11, or as a Goliath framing. See Fig. 8, Plate I., which shows a hydraulic type made for the Tennessee Coal, Iron, and Railroad Co., Ensley, Ala. A telescopic device strips Fig. 7.—Ingot the mould from the ingot, by lifting the mould, while at the same time it prevents the ingot itself from being lifted with the mould from the car. When the strippers are of the travelling type, the moulds can be lifted from the ingots at any place along the runway beneath the bridge of the crane, and deposited in any convenient position.

Mould.