The section Engineering included a wide range of photographs, brochures, blueprints, and objects that illustrated some of the many innovations developed for the World Trade Center. In the foreground is one of the original wind tunnel models used to test the building's design in simulated conditions of hurricane winds. Mounted on the wall behind is an original damper, a steel member used to attach the floor trusses to the columns and to absorb energy of the building's sway. Various photographs of the fabrication and transport of structural steel components were included in the cases, as well as examples of the IBM punch cards used for ordering steel fabrication in a digital format, rather than by the older method of hand-made measured drawings.