Final answer:
Fixed ladders over 20 feet in height typically require a fall protection system, like ladder safety devices, self-retracting lifelines, cages, or rest platforms for worker safety.
Step-by-step explanation:
The question relates to the safety requirements for fixed ladders that exceed a certain height, which is generally a topic covered in engineering or occupational safety courses. According to safety standards, fixed ladders that are greater than 20 feet in length require a safety system to prevent falls. Such systems may include ladder safety devices, self-retracting lifelines, cages, or rest platforms at prescribed intervals. The exact safety requirements can vary by jurisdiction and specific workplace regulations, but the intent is to protect workers from the increased risk of long falls from fixed ladders.
The purpose of these safety features is to prevent falls and provide support for the person using the ladder. A ladder safety system typically consists of a vertical lifeline, a rigid rail or cable system, and a harness. The cage or ladder safety system ensures that the person can safely climb the ladder and prevents them from falling.