What is a critical safety device that may be used with a digger derrick?

The use of an electrical strike warning system is essential because digger derricks are often used in environments where they might come into contact with overhead power lines. This system alerts operators to nearby electrical hazards, significantly reducing the risk of electrical strikes, which can be lethal. It enhances situational awareness and provides an essential layer of safety.

In contrast, while other options like a load limit indicator and emergency stop switch certainly contribute to general operational safety by preventing overloads and allowing for immediate shutdowns, they do not specifically address the unique electrical hazards associated with working near live power lines. Safety harness systems are crucial for fall protection but do not mitigate risks related to electrical strikes, which are particularly important in the context of using a digger derrick.