Which term refers to a large iron or steel beam or compound structure used for building bridges?

• A. Girder
• B. Gusset Plate
• C. Nose Cone
• D. Pier

Answer: (A)

Girders are the large iron or steel beams that form the main horizontal supports of many bridges. They carry the weight of the deck and traffic, then transfer those loads to the piers or abutments. Girders come in different forms, such as I-beam girders, plate girders, or box girders, chosen based on span and load requirements. This makes them the term that fits the description exactly.

A gusset plate, by contrast, is a thick steel plate used to connect members at joints in a truss, not the primary load-bearing beam. A nose cone is unrelated to bridge components and is associated with aerospace contexts. A pier is the vertical support that rises from the foundation to carry loads, not the beam itself.