Tower Structures and Inspection Flashcards
6 cards from real NWSA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Tower Structures and Inspection flashcards as text
According to the ANSI/TIA-222-H standard, what is the maximum recommended inspection interval for a guyed mast tower under normal environmental conditions?
Answer: Every 3 years
The ANSI/TIA-222-H standard specifies that guyed masts should be inspected at intervals of every three years, while self-supporting structures have a longer interval of five years under normal conditions.
During an inspection of a monopole, a technician ensures the small opening at the base of each slip joint is clear of debris. What is the primary purpose of this component, known as a weep hole?
Answer: To permit the drainage of internal condensation and moisture.
Weep holes are designed to allow any moisture that accumulates inside the hollow sections of a monopole to drain out. This prevents the buildup of water which can lead to internal corrosion and damage from freeze/thaw cycles.
An inspector finds severe, localized corrosion where a stainless steel bracket is bolted directly to a galvanized steel tower leg. Which of the following best describes this type of corrosion?
Answer: Galvanic corrosion
Galvanic corrosion occurs when two dissimilar metals (like stainless steel and zinc-coated galvanized steel) are in electrical contact in the presence of an electrolyte (like moisture). The less noble metal (zinc) corrodes at an accelerated rate to protect the more noble metal (stainless steel).
While performing a hands-on inspection of a guy wire, a technician discovers two broken wires within a single strand lay length. What is the generally accepted course of action according to industry standards?
Answer: Immediately report the condition for engineering review and likely replacement.
Most standards and best practices for wire rope and guy strand inspection state that finding two or more broken wires in one lay length is cause for immediate removal from service or replacement. This condition significantly compromises the strength and safety of the guy wire.
Which of the following findings during a visual inspection of a concrete tower foundation would require the most urgent attention and a formal structural engineering assessment?
Answer: A large, vertical crack that runs through a pier and shows signs of displacement.
While minor cracks and cosmetic issues are common, a large structural crack with displacement (meaning the concrete on either side of the crack is no longer aligned) indicates significant movement and a potential failure of the foundation's integrity. This condition requires immediate engineering evaluation.
On a lattice-type self-supporting tower, what is the primary function of the diagonal members that crisscross between the main tower legs?
Answer: To resist shear forces from wind and transfer loads between horizontal members.
In a truss structure like a lattice tower, the diagonal members are critical for providing rigidity and resisting shear (side-to-side) forces. They create triangular shapes, which are inherently stable, and transfer the wind and other lateral loads down the tower to the foundation.