Transcription
member is numbered at the mill, telling its exact location in the structure. Sitting in one spot, the big crane can shake out the steel for the whole job, sorting it according to where each member goes and when it will be needed. Where ground space is at a premium, the steel is stacked within the structure, from where the crane selects each member as needed. Pinpoint spotting is a big thing in setting vertical members. These are bolted or welded together into columns that are based on piles driven down to bedrock. Between the columns, the crane must ease the girders and floor beams into position. One after another, the members are picked from the pile, swung into position, and fastened together. For many years, the clang of riveting has been the voice of structural steel, but today, that voice is being silenced.