Competent Rigger Training Practice Quiz

Explanation
The given correct answer states that all of the mentioned defects can cause a web sling or polyester round sling to be removed from service. A cut or snag can weaken the sling and make it unsafe for use. Excessive abrasion or wear can also compromise the strength and integrity of the sling. Missing or illegible sling identification makes it difficult to determine the sling's working load limit and other important information. Lastly, ultraviolet light damage can degrade the material of the sling, reducing its strength and reliability. Therefore, any of these defects can be a valid reason for removing the sling from service.

Explanation
The lifting load capacity of wire slings is determined by their size. Thicker slings typically have a higher lifting capacity compared to thinner ones because they can withstand greater loads without breaking. Therefore, selecting the appropriate size of wire slings according to the weight of the load being lifted is crucial to ensure safe and efficient lifting operations. In this case, the correct answer is "1"."

Explanation
The angle between two slings in a rigging system plays a critical role in ensuring safe lifting operations. Ideally, this angle should be around 60 degrees to evenly distribute the load among the slings and minimize stress. Deviating significantly from this angle can lead to unequal loading and increase the risk of sling failure. It's essential to accurately calculate and adjust the angle based on factors such as the load weight, rigging configuration, and safety regulations. Following industry standards and guidelines is crucial to determine the appropriate angle and ensure the safety of lifting operations. In this scenario, the correct answer would be 60 degrees for the angle between two slings. 
The load that each leg of the rigging will see can be calculated by dividing the total load by the number of legs.
Total load = 23,120 lbs Number of legs = 4
So, the load per leg = Total load / Number of legs = 23,120 lbs / 4 = 5,780 lbs.
Hence, the correct answer is indeed 5,780 lbs.

Explanation
Based on the sling size determined in the previous question, the minimum shackle size required to lift the load is 3/4".

Explanation
The angle of the slings is 60 degrees. This is determined based on the calculation done in the previous question, which is not provided.

Explanation
Job built overhead lifting devices must go through a thorough engineering process to ensure their safety and functionality. They need to be designed and engineered by a qualified professional engineer (P.E) who has the expertise and knowledge to create a reliable and secure lifting device. Additionally, the device should be built by a qualified fabricator who can execute the engineering plans accurately and according to industry standards. Finally, the lifting device must undergo testing to ensure it can handle the intended load capacity. Testing it to 125% of the intended capacity ensures that it can withstand unexpected stress or overload situations.

Explanation
The most desirable sling angles to have when using multiple leg rigging are 45-70 degrees. This range allows for optimal load distribution and balance between the legs, ensuring the load is evenly distributed and reducing the risk of overload on any individual leg. Sling angles outside of this range may result in uneven loading, increased stress on the rigging system, and potential failure. Therefore, maintaining sling angles between 45-70 degrees is crucial for safe and efficient rigging operations.

Explanation
The minimum recommended sling angle is 30 degrees. This angle is important because it helps distribute the load evenly across the sling and prevents excessive stress on the sling and the load being lifted. A smaller angle can cause the load to shift and potentially lead to accidents or damage to the equipment. Therefore, it is crucial to maintain a minimum sling angle of 30 degrees for safe and efficient lifting operations.

Explanation
The load angle factor is a measure of the angle between the voltage and current waveforms in an electrical system. It is used to determine the power factor and efficiency of the system. In this example, the load angle factor is given as 1.156. This means that the voltage and current waveforms are slightly out of phase, with the voltage waveform leading the current waveform by a small angle. This can indicate a slightly capacitive load, where the system is storing energy.

Explanation
When a shackle is sideloaded at a 90-degree angle, the loss of capacity is 50%. This means that the shackle can only handle half of its original capacity when loaded in this manner. Sideloading refers to applying a load to the shackle at a perpendicular angle to its intended direction. This puts additional stress on the shackle and reduces its ability to bear weight effectively. Therefore, it is important to avoid sideloading shackles to maintain their maximum capacity and ensure safety.

Explanation
The statement is true because overhead lifting products, such as wire rope, synthetic slings, and hardware, must be domestic-made. This means that these products must be manufactured within the country rather than being imported from other countries. This requirement ensures that the products meet certain quality standards and regulations set by the domestic authorities. It also helps to support the local economy by promoting domestic manufacturing and job creation.

Explanation
Kiewit projects are not allowed to use chain rigging in their daily activities.

Explanation
A tear in the outer sheath of an endless polyester sling can weaken the sling and compromise its safety. Any damage to the outer sheath should be taken seriously, and the sling should be removed from service and replaced or repaired as necessary to ensure safety.

Explanation
The maximum included angle of a hook is 90 degrees because this angle allows the hook to open wide enough to hold onto objects securely. A larger angle would make it difficult to grip objects, while a smaller angle would limit the hook's ability to hold onto larger items. Therefore, 90 degrees is the optimal angle for a hook to perform its intended function effectively.

Explanation
The maximum included angle of a screw pin or bolt type shackle is 120 degrees. This means that the shackle can be opened up to a maximum angle of 120 degrees before it becomes unsafe or risks damaging the equipment it is attached to. This angle provides enough flexibility for the shackle to be easily attached and detached, while still maintaining a secure connection.

Explanation
The explanation for the given correct answer is that a lay of wire rope refers to the distance it takes for a single strand to fully spiral around the wire rope. This distance is usually 6 to 7 times the diameter of the rope. Therefore, the statement is true.

Explanation
ANSI B30.9 inspection frequency requires an initial inspection upon purchase before use to ensure that the equipment is in proper working condition. Daily inspections before use are also required to check for any visible damages or defects that may have occurred during previous use. Additionally, periodic inspections not to exceed one year are necessary to assess the overall condition of the equipment and identify any potential issues that may have developed over time. Therefore, all three inspection frequencies are mandated by ANSI B30.9.

Explanation
The statement suggests that periodic rigging inspections will be documented quarterly using a color code system, similar to the assured grounding program. This means that the company has a system in place to regularly inspect the rigging equipment and document the results. The color code system is likely used to easily identify the status of the rigging equipment, ensuring that it is safe and in compliance with regulations. Therefore, the correct answer is true.

Explanation
The maximum wear limitation of hooks and shackles is 10%. This means that once the hooks and shackles have worn down to 10% of their original size or strength, they should be replaced. This is important for safety reasons, as worn hooks and shackles may not be able to support the same load or may be more prone to failure. Regular inspections and maintenance are necessary to ensure that hooks and shackles are in good condition and within the wear limitation.

Explanation
Excessive broken wires, missing I.D tag, and displaced strands are all valid reasons for removing a wire rope from service. Excessive broken wires can weaken the rope and compromise its load-bearing capacity. A missing I.D tag makes it difficult to track the rope's history and determine its suitability for use. Displaced strands indicate internal damage and can lead to further deterioration of the rope. Therefore, all three defects pose safety risks and warrant the removal of the wire rope from service.