Free NCCCO Wire Rope Inspection and Replacement Criteria Questions and Answers — Questions and Answers
Question 1: According to ASME B30.5, running rope on a mobile crane must be removed from service if there are how many broken wires in one lay?
- 3 broken wires in one strand in one lay
- 6 randomly distributed broken wires in one lay (Correct answer)
- 12 randomly distributed broken wires in one lay
- 1 broken wire at an end connection
Correct answer: 6 randomly distributed broken wires in one lay
ASME B30.5 is a key safety standard for mobile cranes. It specifies that a running rope must be removed from service if there are 6 or more randomly distributed broken wires in one rope lay, or 3 or more broken wires in one strand in one rope lay. A 'lay' is the length of rope in which one strand makes a complete spiral around the rope core.
Question 2: What type of wire rope damage is characterized by a loop that has been pulled tight, resulting in permanent deformation and core damage?
- Bird caging
- Kinking (Correct answer)
- Crushing
- High stranding
Correct answer: Kinking
Kinking occurs when a loop is formed in the rope and then pulled tight, causing the wires and strands to be bent and deformed beyond their elastic limit. This permanently damages the rope's structure, significantly reduces its strength, and is a mandatory cause for removal from service.
Question 3: A reduction of the nominal rope diameter of more than what percentage is a cause for rope replacement?
- 2%
- 10%
- 5% (Correct answer)
- 15%
Correct answer: 5%
A noticeable reduction in rope diameter is a sign of internal damage, such as core failure, internal wire breaks, or excessive external wear. Most safety standards, including ASME, state that a reduction in the nominal diameter of more than 5% is cause for immediate removal from service.
Question 4: Which of the following is a clear visual indicator of heat damage to a wire rope?
- Heavy lubrication on the surface
- A slight, shiny appearance on the crowns of the wires
- Blue or rainbow discoloration of the wires (Correct answer)
- The presence of valley breaks
Correct answer: Blue or rainbow discoloration of the wires
When wire rope is exposed to excessive heat, such as from a welding arc or lightning strike, the metal can be annealed, which severely reduces its strength. This damage is often visible as a blue, purple, or rainbow-like discoloration on the wires. Any rope showing such signs must be removed from service immediately.
Question 5: What is the term for the wire rope defect where the outer strands untwist and separate from the core, creating a cage-like appearance?
- Kinking
- High stranding
- Bird caging (Correct answer)
- Core protrusion
Correct answer: Bird caging
'Bird caging' is a specific type of rope failure typically caused by sudden load release (shock loading) or improper installation on a drum. The outer strands flare outwards, forming a shape that resembles a bird cage. This indicates severe structural damage and the rope must be taken out of service.
Question 6: A 'frequent' inspection of the running ropes on a crane in regular service should be conducted how often?
- Annually
- Monthly
- Prior to each shift or daily (Correct answer)
- Only when the operator suspects a problem
Correct answer: Prior to each shift or daily
Crane standards define different inspection intervals. A 'frequent' inspection is a visual examination by a competent or qualified person conducted daily or prior to each shift the crane is used. A 'periodic' inspection is a more in-depth inspection conducted at regular intervals, such as monthly or annually.
Question 7: What is a critical removal criterion for a swaged or poured socket at the end of a wire rope?
- The socket is not painted safety yellow
- The socket shows signs of minor surface rust
- Evidence of cracking, severe corrosion, or rope slippage at the socket (Correct answer)
- The socket is more than 5 years old
Correct answer: Evidence of cracking, severe corrosion, or rope slippage at the socket
The end termination is one of the most critical points of a wire rope assembly. Any sign of cracking in the socket, severe corrosion that causes pitting, or any indication that the rope has slipped or is pulling out of the socket is an immediate cause for removal from service. These conditions indicate the termination's integrity is compromised.
Free NCCCO Wire Rope Inspection and Replacement Criteria Questions and Answers
According to ASME B30.5, running rope on a mobile crane must be removed from service if there are how many broken wires in one lay?