Before using a vehicle, what must workers always refer to due to varying operational zones?

Referring to boom operational charts before using a vehicle is essential because these charts provide critical information about the specific capabilities and limitations of a vehicle's boom, which can vary based on factors such as load weight, radius, and operational zone configurations. Understanding these operational parameters helps ensure that the vehicle is used safely and effectively within its designed operational boundaries.

Boom operational charts typically include data that aids in assessing the maximum allowable loads at various boom angles and extensions, thereby preventing situations that could lead to equipment failure or accidents. They take into account the dynamic aspects of lifting, like wind conditions and load movement, which are essential for maintaining safety when operating in different environmental and physical contexts.

While operational manuals and safety guidelines are important resources to consult, they do not provide the specific, real-time information necessary for assessing boom performance under varying conditions. Load angle charts, while relevant, focus more specifically on load distribution and balance rather than the broader operational capabilities of the boom. Thus, consulting boom operational charts is the most critical action for ensuring safe and effective operations before using a vehicle.