A basic shear such as this could be used to cut rod and bar stock up to a width of about 4 inches.
The raw material for the bridge shop, consisting of plate, bar stock, I-beams, angles, and other rolled forms, was cut to size not with saws but with powerful shears that were able to cut through steel as easily as a paper cutter cuts through paper. The blades to the shears were made of special steel, and the necessary force came from a series of reduction gears powered by the shop's overhead line shafting, pulleys, and belts.
The same basic machine was used to punch holes where the pieces would eventually be riveted together. The process, using a cylindrical die to punch a hole, was identical to that used in a paper punch, though the force required was much greater. These holes, typically 3/4 of an inch or an inch in diameter, would be carefully laid out using the drawings prepared by the company's engineering staff. Some punches could make more than one hole at a time. Once cut to size by the shears and punched with rivet holes, the pieces were ready to be riveted together to make bridge parts.
A basic shear such as this could be used to cut rod and bar stock up to a width of about 4 inches.
The box girders that made up the end posts and top chord of a bridge truss required pieces of iron plate that were 6 to 12 inches wide, and floor beams could require even wider pieces of plate. These were cut to length on a plate shear such as this.
Specialized shears such as this angle cutter were also needed. Cutting an angle-section piece of iron on an ordinary shear would crumple it before it was cut all the way through.
This is a basic punch that could put a hole through iron that was a half-inch thick or even more. Mechanically, it is identical to the basic shear above, except for having a cylindrical punch instead of a cutting blade.
This punch could make three holes at once.
Although its single punch can only make one hole at a time, this machine is fitted with a table that feeds the work past the punch mechanically, allowing a series of holes, at a set interval, to be punched automatically without repositioning the work.