angle, beam, and plate shears; coping machines for coping I-beams and channels; planers for trimming the edges of plates; planing or milling machines; and machines for ending stiffeners and chamfering them so as to fit the flange angles. Planing or chamfering machines can be designed with one head fixed and one movable, so as to permit the setting of the heads a given distance apart, whereby both ends of a number of stiffeners can be chamfered at one setting, and all the duplicate pieces chamfered while the heads are a given distance apart.

Punching

In punching, the material has to be handled in individual pieces. Jib-cranes or traveling wall-cranes should, therefore, cover the tool area; and overhead cranes should be provided for transferring the material to and from the punches in quantities. As an, alternative, facilities for trucking the said material in quantities might be provided. Punches, to as great an extent as possible, should be equipped with spacing-tables of some of the various standard designs; and, where practicable, the punching should be done by spacing machines. The cost of punching a given number of holes is reduced thereby, the marking-off of the material is eliminated, and, in most cases, the cost of templet-making is diminished. It is also possible to punch a larger number of holes within a given time; and the increase in capacity of the Punch Shop would make spacing-punches economical, even if the actual cost of doing the work were the same. In addition to this, as a rule, the work is more accurate, which condition militates for economy, in that the fitting-up is facilitated.

It is probable that more small, labor-saving devices have been introduced in Punch Shops than in any other part of the fabricating plant— such, for instance, as electrically-operated gags, ball tables, punching through wooden or pasteboard templets, using a model and applying the principle of the pantagraph, etc.

Drilling

Many bridge specifications require metal of over a certain thickness to be drilled instead of punched; and often such drilling really proves to be more economical than the punching. The shop, therefore, that is going to handle heavy bridgework has to have, in addition to its punching equipment, a sufficient number of power drills to permit the drilling from the solid of a considerable tonnage of metal. If the shop is designed especially for this class of work, sufficient drills should be provided to handle from fifty to seventy-five per cent of the normal output of the shop.*

*The author predicts that it will not be many years before all important steel bridgework will be drilled solid, and that the increased cost of so doing will amount practically to zero.