Ironworkers constructing a centre column for a New York Skyscraper. They are making a 'Carnegie Beam' from massive pieces of Iron. Great footage of men using riveteting machines and brute force to manufacture these iron-leviathons

Carnegie made major technological innovations in the 1880s especially in the installation of the open hearth system at Homestead in 1886. It now became possible to make steel suitable for structural beams and for armor plate for the US Navy which paid far higher prices for the premium product.