What is the main purpose of the overhaul ball (headache ball) on a single-part whipline?
- Its weight adds to the crane's rated capacity when on the whipline
- It stops the hook from being drawn into the boom tip
- Its weight keeps the line taut and pulls it down when unloaded
- It measures the load on the line for the operator
Show the answer
C. Its weight keeps the line taut and pulls it down when unloaded
With no load on the hook, the ball's weight overcomes friction and the weight of rope on the drum side so the line pays out and stays seated in the sheaves. Its weight is a deduction from capacity, never an addition.
Reference: Mobile crane components
Who must carry out the visual shift inspection of a crane, and when?
- A competent person, beginning before each shift the crane is used
- A qualified person, once at the start of each working week
- A registered engineer, before the first lift on each new site
- The lift director, after the last lift of each working day
Show the answer
A. A competent person, beginning before each shift the crane is used
A competent person must begin a visual inspection before each shift the equipment will be used and complete it before or during that shift. A qualified person is required for the annual comprehensive inspection, not the shift check.
Reference: 29 CFR 1926.1412(d)(1)
What are boom stops on a lattice boom crane for?
- To keep the boom from going over backward
- To limit how far the boom can be lowered
- To hold the boom when the pendants are removed
- To stop the upperworks from swinging freely
Show the answer
A. To keep the boom from going over backward
Boom stops resist the boom being pulled or blown back past its highest working angle, for example if a load is suddenly released. They are a safety device that must be working before operations begin.
Reference: 29 CFR 1926.1415(a)(2)