NWSA Hoisting and Rigging Practices 2 — Questions and Answers
Question 1: What is the primary purpose of a lift plan for tower hoisting operations?
- To calculate labor costs
- To document the load weight, rigging configuration, equipment ratings, and step-by-step procedure to ensure a safe lift (Correct answer)
- To determine how many breaks workers get
- To schedule material deliveries
Correct answer: To document the load weight, rigging configuration, equipment ratings, and step-by-step procedure to ensure a safe lift
A lift plan ensures all aspects of the hoisting operation have been thought through and equipment is properly rated.
A lift plan includes load description and weight, rigging configuration with rated capacities, equipment ratings, anchor point details, step-by-step procedure, personnel assignments, communication plan, hazard assessment, and emergency procedures.
Question 2: What is the difference between a bridle hitch and a basket hitch for sling use?
- They are the same thing
- A bridle hitch uses two separate slings to support a load from above, while a basket hitch wraps a single sling under and around the load (Correct answer)
- A bridle hitch is only for wire rope
- A basket hitch is only for synthetic slings
Correct answer: A bridle hitch uses two separate slings to support a load from above, while a basket hitch wraps a single sling under and around the load
Different hitch configurations provide different load control and capacity characteristics.
Bridle hitch uses two or more separate slings connected to a common lifting point. Basket hitch passes a single sling under the load with both ends connected to the hook, effectively doubling capacity. Choker hitch wraps around the load but reduces capacity to about 75%.
Question 3: Why must hoisting equipment be de-energized and secured when not actively in use on a tower?
- To save electricity
- To prevent unauthorized operation, accidental activation, and damage from weather exposure (Correct answer)
- De-energizing is optional during short breaks
- Only at the end of the project
Correct answer: To prevent unauthorized operation, accidental activation, and damage from weather exposure
Unsecured hoisting equipment can be accidentally activated, operated by unauthorized persons, or damaged by weather.
Accidental activation from wind-blown controls or faults can move loads unexpectedly. Untrained persons may attempt operation. Weather can damage controls. Unsecured lines can wrap around tower members. An unattended hoist under load is always unacceptable.
Question 4: What inspection is required for hooks used in hoisting operations?
- Hooks don't need inspection if they appear fine from a distance
- Check for deformation, cracks, throat opening increase, twist, wear on the saddle, and verify the safety latch functions properly (Correct answer)
- Only check if the hook is rusty
- Hook inspection is only required annually
Correct answer: Check for deformation, cracks, throat opening increase, twist, wear on the saddle, and verify the safety latch functions properly
Hook failure during a loaded lift results in an uncontrolled load drop.
Per ASME B30.10: throat opening increase of more than 15% means retirement. Check for twist, cracks in the saddle area, wear, safety latch function, corrosion, heat damage, and shank/nut condition. Hooks must never be repaired by welding or re-bending.
Question 5: What is the proper procedure for receiving a load at the top of a tower?
- Reach out and grab the load as it approaches
- Guide the load using a tag line or hands-free technique, ensure personal fall protection is secure, and never position yourself under the load (Correct answer)
- Standing under the load is acceptable if wearing a hard hat
- Let the load swing until it stops naturally
Correct answer: Guide the load using a tag line or hands-free technique, ensure personal fall protection is secure, and never position yourself under the load
Receiving a load at height requires proper positioning, secure personal fall protection, and controlled load guidance.
Verify fall arrest is secure before the load arrives. Never position yourself directly under the ascending load. Use a tag line to control approach rather than grabbing with hands. Communicate clearly with the hoist operator. Have a clear landing zone prepared.
Question 6: What is a critical lift and what additional precautions does it require?
- Any lift over 10 pounds is critical
- A lift involving maximum equipment capacity, irreplaceable items, proximity to hazards, or unusual conditions requiring enhanced planning and supervision (Correct answer)
- Only lifts performed with a crane are critical
- Critical lifts only occur during initial tower construction
Correct answer: A lift involving maximum equipment capacity, irreplaceable items, proximity to hazards, or unusual conditions requiring enhanced planning and supervision
Critical lifts involve higher-than-normal risk factors that require additional planning and supervisory oversight.
Criteria include load exceeding 75-80% of component capacity, personnel in the drop zone, irreplaceable loads, lifting over occupied spaces, tandem lifts, loads with high wind profiles, and lifts near energized lines. Additional precautions include engineering review, pre-lift meeting, dry run, and management oversight.
NWSA Hoisting and Rigging Practices 2
What is the primary purpose of a lift plan for tower hoisting operations?