Question T0B05
From subelement T0 - T0B
What is the purpose of a safety wire through a turnbuckle used to tension guy lines?
Why is this correct?
The correct answer is B because turnbuckles naturally loosen over time due to wind-induced vibration and thermal expansion/contraction cycles. A safety wire threaded through the turnbuckle holes and twisted prevents this loosening. Choice A is wrong because the wire doesn't replace the turnbuckle's function if it breaks. Choice C is incorrect as guy wires themselves provide the lightning path, not the safety wire. Choice D is wrong because the wire has no measurement function.
Memory tip
Look for the most direct, mechanical purpose when safety devices are mentioned. Safety wires always prevent unwanted movement or loosening—this pattern applies across many mechanical systems in amateur radio installations, from antenna rotators to tower hardware.
Learn more
Guy wire tension is critical for tower structural integrity under wind loading and ice accumulation. The turnbuckle adjustment allows precise tensioning to manufacturer specifications, but constant environmental forces create loosening torque. A simple safety wire costs pennies but prevents catastrophic tower failure. Professional tower installations often use specialized locking hardware, but the basic principle remains: secure all adjustable connections against vibration-induced loosening to maintain structural safety margins.
Think about it
Why do you think vibration affects turnbuckles more than other tower hardware connections, and what would happen to tower stability if multiple guy wire turnbuckles loosened simultaneously?