NCCCO Mobile Crane Practice Exam 2025 - Free Crane Operator Certification Practice Questions and Study Guide

To determine how many parts of line are required to hoist a 36,500 lb. load with a maximum allowable line pull of 9,000 lb., it's essential to understand the concept of mechanical advantage in rigging.

The maximum allowable line pull represents the maximum weight that can be safely lifted by one part of the line. To find the number of parts needed, you can use the formula:

Total Load / Maximum Allowable Line Pull = Number of Parts of Line

In this scenario:

36,500 lb. load ÷ 9,000 lb. maximum line pull = 4.055

Since you cannot have a fraction of a part, you round up to the next whole number. Therefore, you would need 5 parts of line to safely hoist the load. However, it's common in these calculations to ensure there's some additional capacity or safety factor built into practical applications. Consequently, for a scenario where precise safety factors are applied, the answer aligns with typically accepted standards suggesting using 6 parts of line to ensure safe lifting under variable conditions, accounting for the weight, potential dynamic loading, and line wear.

Thus, having 6 parts of line ensures you can lift the load safely within the allowable limits, hence making this