Which wire is a solid wire suspended from the messenger wire to which the contact wire is attached?

• A. Auxiliary Wire
• B. Ground Wire
• C. Shield Wire
• D. Bus Jumper

Answer: (A)

In overhead traction systems, the messenger wire is the main high-tension line that spans between structures. A solid auxiliary wire is suspended from that messenger and serves as the support to which the contact wire—the energized line the pantograph touches—is attached. This setup keeps the contact wire in the correct position and tension along the span. The other wires have different roles: a shield or ground wire protects against lightning, while a bus jumper is a connection used in equipment, not part of the span’s contact-wire arrangement. So, the wire described is the auxiliary wire.