Most jib ratings are typically based on what factor?

Jib ratings are primarily determined by the structural strength of the jib itself. This consideration is critical because the structural integrity directly affects the ability of the jib to support loads safely. When calculating the rating, engineers assess the materials used, the design of the jib, and its capability to handle stress and strain during operation.

While operational environment, weight of the crane, and length of the jib can influence the overall performance and efficiency of the crane, they do not primarily dictate the rating assigned to the jib. The structural strength is the foundational factor that ensures safety and performance under load conditions. Therefore, the correct understanding hinges on recognizing that the jib's design and ability to withstand forces are what fundamentally establish its rating.