The labor involved in these operations is generally not excessive measured in foot-pounds of work performed, but must be done in a relatively short time to permit the cast house to be cleared for the next cast, therefore the men have to do the work under high pressure and under excessively disagreeable conditions owing to the heat and dust.

In order to overcome these hindrances to continuous and inexpensive operation the Duquesne furnaces were provided with chill beds, but they were also provided with a crane in the cast house and the individual pigs were made vastly larger, both of heavier cross section and much longer than the ordinary pig, and were picked up by the crane which carried them to what was probably the first mechanical pig breaker. There they were laid down upon a table of rollers which fed them up to a hydraulic plunger working up and down which broke them into short sections.

Since that time the introduction of the crane in the cost house has become more general and should be universal. It is not only an enormous saving of labor in handling the iron, as I shall presently show, but is a convenience of incalculable value in times of breakouts, boils, putting in and taking out iron troughs, and assisting in the operation generally.

Fig. 213. Interior of cast house with pile of combs from pig beds, one hanging from crane.

Since the time of the Duquesne revolution the pig breaker has been much more highly developed, and in modern plants where pig beds are still used the handling of the iron is reduced to a mechanical operation.

The Brown Hoisting Machinery Company of Cleveland have developed the pig breaker in most common use, and through their courtesy I am able to show in Figs. 212, 213, 214, 215 and 216 the whole operation of handling the iron. In Fig. 212 there will be seen suspended from the crane an I-beam carrying a number of heavy steel hooks. These hooks are lowered down over the bed and two or more of them are hooked under the sow and raise it on to blocks as shown in Fig. 213, in which position a fresh hold is taken of it with practically all the hooks engaged, the whole comb constituting a bed of two or three tons weight, may be either taken directly to the breaker in the rear or piled up as shown to the left of the breaker at the rear of the cast house. This is particularly convenient in case it is desired to have the analysis of the whole cast before breaking the iron and delivering it into the cars.

Fig. 213 shows the pig bed hanging from the hooks with its end entering the jaws of the breaker. It will be noted that the breaker is set at a high level, and in the center between the two piers on which it rests may be seen a chute leading out of the arched doorway at the rear. Into this chute the pigs drop as they are broken and slide into the car which takes them to their destination. The iron therefore is practically never touched by hand in any way until it comes to be unloaded at its destination, and while that is no part of our present concern, it is not amiss to say that that operation is now very generally carried on by huge magnets operated by cranes, so that even there no hand labor is required.

Fig. 214. Side view of pig breaker.

Figs. 214, 215 and 216 show the pig breaker itself. The vertical column at the left, (Fig. 214) carries two horizontal plungers, one above the other, operated by hydraulic pressure. The column at the right acts merely as an anvil. In operation the comb is fed between the jaws by the crane; the first plunger is driven out against the top of the pig just where it joins the sow, and forces this over firmly against the anvil. The lower plunger is then forced out against the projecting bottom end of the pig, which it breaks off across the horizontal fulcrum seen about midway of the height of the anvil. This breaks the pig in two, the sow being supported by its top edge, with the bottom edge unsupported, while the end of the remaining portion of the pig is supported on the fulcrum; more pressure is then thrown on the top plunger, which is opposite the unsupported bottom edge, and this additional pressure breaks the pig loose from the sow, and the sow is then broken into suitable lengths by proper manipulation of the position of the comb and of the pig breaker itself.

The hole in the floor just to the right of the operator (in Fig. 214) delivers the pig into the top of the chute shown in Fig. 213. There is one of these on each side of the machine, so that no matter on which side the pig falls it reaches the same destination.

Fig. 215. Pig breaker, showing hydraulic cylinder and anvil.

A pig machine has also been brought out by Mr. James B. Ladd of Philadelphia, but the principle of this machine, while somewhat different from that of the Brown, is not so radically different as to require separate illustration.

The amount of labor saved by the introduction of this equipment is enormous. When it is realized that 500 tons is considered the normal output of a standard size furnace in the Lake Ore district, and that under the old regime this would have required to be broken by hand, then carried piece by piece and thrown on to trucks, by them conveyed from the cast house to the railroad car, and then thrown from the trucks to the railroad car, it will be seen that the labor involved was tremendous and of the heaviest and most undesirable kind. Such labor is increasingly difficult to secure, and to handle, and where pig iron must continue to be cast in sand, the introduction of methods of handling it by machinery is almost a necessity.