Associate Safety Professional Practice Exam

What is the working load limit for a hoisting chain with a minimum breaking strength of 25 tons, which has been proof tested to 33,000 pounds?

1. 10,000 lbs

2. 16,500 lbs

3. 25,000 lbs

4. 33,000 lbs

The correct answer is: 16,500 lbs

The working load limit (WLL) for a hoisting chain is determined based on a percentage of its minimum breaking strength (MBS), taking into account safety factors. In many standards and applications, the WLL is typically set at a fraction of the MBS, often using a safety factor of 4:1 for chain lifting equipment. In this case, the minimum breaking strength is given as 25 tons, which is equivalent to 50,000 pounds (since one ton equals 2,000 pounds). When applying a safety factor of 4:1, the calculation for the WLL would be as follows: WLL = MBS / Safety Factor WLL = 50,000 lbs / 4 WLL = 12,500 lbs However, it is also important to consider the proof test result. The chain has been proof tested to 33,000 pounds, which suggests that under testing, the chain proved capable of handling loads up to this amount without failure. Generally, the actual WLL would typically be the lesser of the two values derived from breaking strength and proof test results, respecting any applicable standards or regulations that might be in place. If you assert that the WLL is set at