NCCCO Tower Crane Operator Test 1 5 — Questions and Answers
Question 1: Which condition requires an immediate shutdown of a tower crane and notification of the competent person?
- A sudden load swing of more than 10 degrees during travel
- Discovery of a broken wire rope strand exceeding ASME B30.3 removal-from-service criteria (Correct answer)
- Wind gusts exceeding 10 mph during a critical lift
- The counterweight shifting 2 inches from its original position
Correct answer: Discovery of a broken wire rope strand exceeding ASME B30.3 removal-from-service criteria
ASME B30.3 specifies broken wire criteria that, when met, require immediate removal from service until the rope is replaced.
Question 2: What is the maximum allowable slope for a tower crane base when the manufacturer's specification states the crane must be level?
- 1 degree
- 3 degrees
- 5 degrees
- The manufacturer's tolerance, typically within 1/500 (0.2%) of plumb (Correct answer)
Correct answer: The manufacturer's tolerance, typically within 1/500 (0.2%) of plumb
Tower cranes must be installed to the manufacturer's plumb tolerance, which is typically within 1/500 of the mast height.
Question 3: When performing a pick-and-carry operation with a tower crane, what is the most critical consideration?
- Tower cranes are not designed for travel with a suspended load and must never pick-and-carry (Correct answer)
- The load must not exceed 25% of rated capacity during travel
- Outriggers must be deployed before initiating any travel
- The boom must be fully retracted before moving the crane on rails
Correct answer: Tower cranes are not designed for travel with a suspended load and must never pick-and-carry
Tower cranes are stationary structures and are never designed for pick-and-carry operations; they must remain fixed during all lifts.
Question 4: A qualified rigger attaches a load using a single-leg wire rope sling at a 45-degree angle from vertical. How does this affect the sling's capacity compared to a vertical hitch?
- Capacity increases because the sling length is longer
- Capacity remains unchanged because the hook bears the full load
- Capacity is reduced because the sling experiences a higher tension than the load weight (Correct answer)
- Capacity doubles because tension is shared with the crane's load line
Correct answer: Capacity is reduced because the sling experiences a higher tension than the load weight
At 45 degrees from vertical, the sling tension exceeds the load weight by approximately 41%, reducing its effective working load limit.
Question 5: Under OSHA 29 CFR 1926.1431, what is the maximum number of workers permitted to be hoisted in a personnel platform (man basket) on a tower crane?
- No more than 2 workers at any time
- The maximum number that can be safely fit inside, with no weight limit
- The number specified by the load chart minus 25% for the personnel platform weight
- The number specified by the platform manufacturer not to exceed the platform's rated capacity (Correct answer)
Correct answer: The number specified by the platform manufacturer not to exceed the platform's rated capacity
OSHA requires that occupancy not exceed the platform's rated capacity as specified by the manufacturer.
Question 6: What action should a tower crane operator take if power is lost while a load is suspended?
- Immediately apply all manual brakes and contact the competent person before lowering
- Lower the load using the emergency power-off descent control if equipped, or wait for power restoration (Correct answer)
- Abandon the cab and allow the load brake to hold the load indefinitely
- Manually release the load line so the load descends slowly by gravity
Correct answer: Lower the load using the emergency power-off descent control if equipped, or wait for power restoration
Most tower cranes have spring-set brakes that hold the load on power loss; the operator should use the emergency lowering device if available and follow the site emergency plan.
Question 7: Which NCCCO certification is specifically required to operate a tower crane on a US job site?
- CCO Mobile Crane Operator (Lattice Boom Truck Crane)
- CCO Tower Crane Operator (TCO) (Correct answer)
- CCO Rigger Level II
- CCO Signal Person certification
Correct answer: CCO Tower Crane Operator (TCO)
The NCCCO Tower Crane Operator (TCO) certification is the credential specifically required for tower crane operation.
NCCCO Tower Crane Operator Test 1 5
Which condition requires an immediate shutdown of a tower crane and notification of the competent person?