Tower Crane Erection, Climbing, and Dismantling Flashcards
6 cards from real NCCCO 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 Crane Erection, Climbing, and Dismantling flashcards as text
What is the purpose of a tower crane's climbing frame (climbing collar)?
Answer: To allow the crane to be raised incrementally by inserting new mast sections during top climbing
The climbing frame surrounds the mast and uses hydraulic cylinders to jack the crane upward, creating space for new mast sections to be inserted below the slewing unit during top climbing operations.
What must be verified regarding the tower crane base before erection begins?
Answer: The foundation has been designed by a licensed engineer and has reached sufficient cure strength before crane loading
The tower crane foundation must be designed by a licensed professional engineer for the specific crane and site conditions, and the concrete must reach the required cure strength before any crane loads are applied.
What is the ballast (counterweight) adjustment requirement when a tower crane's jib length is changed?
Answer: Counterweight configuration must be adjusted to match the new jib length per the manufacturer's specifications
Changing jib length alters the load moment arm and the crane's balance point, requiring a corresponding counterweight adjustment to maintain proper balance and ensure load chart validity.
What is the maximum wind speed limit that must be observed during tower crane assembly and dismantling operations?
Answer: Assembly and dismantling have lower wind speed limits (typically 20-25 mph) than normal operation limits
Assembly and dismantling operations are more sensitive to wind than normal crane operations; most manufacturers specify lower maximum wind speeds (typically 20-25 mph) for these activities due to the structural instability of partially assembled components.
What is a 'free-standing height' in tower crane terminology?
Answer: The maximum crane height that can be erected without internal ties or external anchors to the structure
Free-standing height is the maximum mast height at which the crane is self-supporting without external ties to an adjacent structure, based on the mast section strength and foundation design.
What OSHA regulation specifically governs tower crane erection, climbing, and dismantling?
Answer: 29 CFR 1926.1435
OSHA 29 CFR 1926.1435 specifically addresses tower cranes in construction, including assembly and disassembly requirements, inspections, operator qualifications, and operational requirements.