FREE NWSA Rigging and Hoisting Operations Questions and Answers

Question 1

A rigging plan requires lifting a 1,200 lb antenna using a two-leg bridle sling. The length of each sling leg (L) is 10 feet, and the vertical height from the load to the hook (H) is 7 feet. What is the approximate tension on each sling leg?

Accepted Answer

857 lbs

Answer

The tension on each sling leg is calculated by first finding the load per leg if it were a vertical lift (1,200 lbs / 2 legs = 600 lbs). Then, calculate the load factor, which is the sling length (L) divided by the height (H) (10 / 7 ≈ 1.428). Finally, multiply the vertical load per leg by the load factor (600 lbs * 1.428 ≈ 857 lbs). As the angle between the slings decreases, the tension on each leg increases significantly.

Question 2

When operating a capstan hoist to lift materials, what is the primary reason for maintaining a specific number of wraps on the drum and applying tension to the fall line?

Accepted Answer

To create sufficient friction for the hoist to grip the rope and manage the load

Answer

A capstan hoist does not store the rope on the drum like a winch. It works by using the friction between the rope and the rotating drum (capstan head). The operator must maintain the correct number of wraps and apply tension to the non-load-bearing end of the rope (the fall line) to create enough friction for the drum to grip the rope and move the load.

Question 3

Which of the following standards, developed jointly by the Telecommunications Industry Association (TIA) and the American Society of Safety Professionals (ASSP), specifically addresses the 'means and methods' of construction and safety practices for communication structures?

Accepted Answer

ANSI/ASSP A10.48

Answer

ANSI/ASSP A10.48, 'Criteria for Safety Practices with the Construction, Demolition, Modification and Maintenance of Communications Structures,' is the standard that focuses on the safety of tower workers, covering the means and methods to be employed during work. ANSI/TIA-322 covers the engineering, design, and loading analysis, while TIA-222 is the structural standard for the towers themselves.

Question 4

A gin pole is being used to lift a new tower section. Which component of the gin pole assembly is primarily responsible for attaching the entire apparatus to the existing tower structure?

Accepted Answer

The clamp assembly

Answer

A gin pole consists of three basic parts: a pole (mast), a pulley assembly (rooster head/load block), and the clamp assembly. The clamp assembly is what physically secures the gin pole to the leg or a structural member of the tower, providing the foundation for the lift.

Question 5

When inspecting rigging equipment before a lift, a technician discovers a wire rope sling with 'birdcaging'. What is the correct course of action?

Accepted Answer

Remove the sling from service immediately

Answer

Birdcaging is a form of distortion in a wire rope where the strands untwist and separate, creating a cage-like appearance. This indicates core failure or shock loading and severely compromises the rope's strength. Any rigging equipment showing signs of kinking, crushing, or birdcaging must be immediately removed from service and destroyed to prevent accidental reuse.

NWSA - National Wireless Safety Alliance Practice Test

NWSA - National Wireless Safety Alliance Practice Test

FREE NWSA Rigging and Hoisting Operations Questions and Answers