Free NCCCO Service Truck Crane Operator Test 1 — Questions and Answers
Question 1: What is the load block sheaves' minimum pitch diameter?
- at least 15 times the diameter of the rope
- at least 20 times the diameter of the rope
- at least 18 times the diameter of the rope
- at least 16 times the diameter of the rope (Correct answer)
Correct answer: at least 16 times the diameter of the rope
This is a specific safety standard in crane operation, typically outlined by ASME B30.5 for mobile and locomotive cranes. The minimum pitch diameter for load block sheaves must be at least 16 times the nominal diameter of the wire rope. This ratio is critical for minimizing wear, fatigue, and stress on the wire rope, thereby extending its lifespan and ensuring safe lifting operations.
Question 2: When lifting with crawler cranes, which boom position would result in the most ground pressure?
- Beyond the corner (Correct answer)
- Beyond the edge
- Above the front
- Above the back
Correct answer: Beyond the corner
When a crawler crane lifts a load, the ground pressure exerted by its tracks varies with the boom's position. Lifting 'beyond the corner' means the boom and load are positioned diagonally off one of the tracks' corners. This configuration concentrates the crane's weight and the load's forces onto a smaller area of the track, resulting in the highest localized ground pressure compared to other boom positions.
Question 3: When can outrigger beams be covered with blocking (cribbing)?
- Never (Correct answer)
- Always
- Infrequently
- Sometimes
Correct answer: Never
Outrigger beams are structural components designed to extend horizontally from the crane's chassis to provide stability. Blocking (cribbing) is used *under* the outrigger pads to distribute the load over a larger ground area, not *over* the beams themselves. Covering outrigger beams with blocking is a dangerous practice that can interfere with their proper function, compromise structural integrity, and lead to crane instability, so it should never be done.
Question 4: What is the boom hoisting sheaves' minimum pitch diameter?
- at least 20 times the diameter of the rope
- at least 16 times the diameter of the rope
- at least 15 times the diameter of the rope (Correct answer)
- at least 18 times the diameter of the rope
Correct answer: at least 15 times the diameter of the rope
This is a specific safety standard for crane rigging, similar to load block sheaves but with a slightly different ratio. For boom hoisting sheaves, industry standards (such as ASME B30.5) require a minimum pitch diameter of at least 15 times the nominal diameter of the wire rope. This ratio helps to reduce stress and wear on the wire rope as it passes over the sheaves, contributing to the overall safety and efficiency of the hoisting mechanism.
Question 5: Which accessible section of a working crane must to be blocked off all the time, according to OSHA?
- From the top of the reel to the top of the drum, the rope extends.
- They depend on the crane's steadiness.
- The revolving superstructure's back swing radius (Correct answer)
- Depending on which next boom length is shorter or longer and has a lower capacity
Correct answer: The revolving superstructure's back swing radius
OSHA regulations (specifically 29 CFR 1926.1424(a)(2)) mandate that the area within the swing radius of a crane's rotating superstructure, where there is a risk of an employee being struck or crushed, must be barricaded or otherwise prevented from employee entry. This 'back swing radius' is a critical danger zone, and blocking it off ensures the safety of personnel working near the crane.
Question 6: When ought one to employ a tagline?
- From the top of the reel to the top of the drum, the rope extends.
- The separation between the load's center of gravity and the crane's center of rotation
- When a load's rotation could be hazardous 1910.180(h) & 1926.1417(w)(3)(xvi) If it becomes essential, a tag or restraint line must be employed to stop the weight from rotating in a dangerous way. (Correct answer)
- Crane capacity in the gray regions above the bold lines are determined by hydraulic or structural constraints. Based on stability ratings, the crane capacity are below the bold lines.
Correct answer: When a load's rotation could be hazardous 1910.180(h) & 1926.1417(w)(3)(xvi) If it becomes essential, a tag or restraint line must be employed to stop the weight from rotating in a dangerous way.
A tagline is a rope or line attached to a load being lifted by a crane, used by ground personnel to control its movement. As per OSHA regulations (1926.1417(w)(3)(xvi)), a tagline must be employed when a load's rotation or swinging could be hazardous. Its primary purpose is to prevent uncontrolled movement, ensuring safety for both the load and personnel in the vicinity.
Question 7: In the context of load capacity charts, what does "jib angle to ground" mean?
- The front
- main boom angle less the offset of the jib (Correct answer)
- Divide the hoist lines.
- only when loads are freely suspended
Correct answer: main boom angle less the offset of the jib
A jib is an extension attached to the main boom of a crane. The 'jib angle to ground' is not directly measured from the ground but is calculated by taking the main boom's angle relative to the horizontal and subtracting the offset angle at which the jib is attached to the main boom. This calculation is essential for accurately determining the crane's radius and load capacity when a jib is in use.
Question 8: What is the rotation resistant rope's safety factor for lifting people?
- 5:1
- 28:2
- 10:1 (Correct answer)
- 20:1
Correct answer: 10:1
When cranes are used to hoist personnel in a man basket or platform, extremely stringent safety factors are required due to the high risk. For rotation-resistant wire rope used in personnel hoisting, OSHA and ASME standards (e.g., ASME B30.23) mandate a minimum design factor (safety factor) of 10:1. This means the rope's breaking strength must be at least ten times the maximum anticipated load, providing a significant margin of safety.
Question 9: What happens if you place timber blocking beneath a crawler crane's track tips?
- He or she plans to proceed.
- Divide the hoist lines.
- increases the stability of the crane (Correct answer)
- lowers the crane's capacity
Correct answer: increases the stability of the crane
Placing timber blocking (cribbing) beneath the track tips of a crawler crane effectively increases the footprint or bearing area of the tracks, particularly when the boom is positioned over the ends. This wider base distributes the crane's weight and the load over a larger surface, which in turn increases the crane's stability by reducing localized ground pressure and preventing the tracks from sinking or tilting.
Question 10: What is the minimal distance under $50,000 that can be kept between a crane and electrical lines?
- 6 ft.
- 15 ft.
- 10 ft. (Correct answer)
- 20 ft.
Correct answer: 10 ft.
OSHA regulations (29 CFR 1926.1408) specify minimum clearance distances between cranes and power lines to prevent electrocution hazards. For power lines rated up to 50 kV (50,000 volts), the minimum clearance distance required is 10 feet. This distance must be maintained at all times during crane operation, including the boom, load, and rigging, to ensure worker safety.
Question 11: When operating at ground floor level close to a cellar wall, where should the outrigger pads or tracks of the crane be positioned?
- At least as far back as the wall's subsurface depth (Correct answer)
- The revolving superstructure's back swing radius
- Just far enough above the surface to release the crane weight off the tires
- As long as it doesn't produce any obvious distortion that would compromise procedures that are safe
Correct answer: At least as far back as the wall's subsurface depth
When operating a crane near an excavation or cellar wall, the ground directly adjacent to the wall may be unstable and prone to collapse. To ensure stability and prevent the crane from overturning or the ground giving way, the outrigger pads or tracks must be positioned far enough back from the edge of the excavation, at least equal to the depth of the subsurface wall. This ensures the crane is on undisturbed, stable ground.
Free NCCCO Service Truck Crane Operator Test 1
What is the load block sheaves' minimum pitch diameter?