In a trussed beam, what is the top or bottom component called?

In a trussed beam, what is the top or bottom component called?

• A. Rail
• B. Rung
• C. Truss blocks
• D. Halyard

Answer: (A)

In a trussed beam, the long horizontal members that run along the top and bottom form the frame and are known as rails (also called the top and bottom chords). These rails carry the primary axial forces: the top rail resists compression and the bottom rail resists tension when the beam bends. The other members are the diagonal webs that transfer forces between the rails, helping keep the structure stable. A rung belongs to ladders, truss blocks aren’t standard terminology for trusses, and halyard refers to a rope used to hoist something. So the top or bottom component is called a rail.