What signal should be used to indicate to move the tines in or out?

The correct signal to indicate moving the tines in or out is to extend the arm with the palm facing down and point the forefinger in the direction of the intended movement. This method of signaling is clear and unambiguous, allowing the operator to easily understand the specific direction in which to move the equipment.

Using the forefinger to point provides a visual cue that is essential for effective communication on a construction site, where noise and environmental factors can hinder verbal instructions. The arm extended and palm down communicates a directive action, reinforcing the intended movement and ensuring that all personnel involved in the operation are on the same page regarding the actions to be taken with the hoisting equipment.

Signals that involve vertical forearms or fists may not provide as clear of a directional instruction, leading to possible confusion about the intended movement. It's crucial for operators and ground personnel to have a standardized system of communication, and this chosen gesture fits well within typical signaling practices in crane operations.