Which type of crane does NOT require a boom angle indicator?

A crane with a fixed-length and angle boom does not require a boom angle indicator because the configuration of the boom is static and does not change during operation. Since the length and angle of the boom remain constant, there is no need to monitor or indicate the boom's angle, as it will always be at the same position. This simplifies operation and reduces the chances of an error associated with adjusting or misreading the boom angle.

In contrast, cranes with telescoping booms, variable angle booms, and luffing jibs all involve moving parts that can change the angle of the boom during operation. These types require boom angle indicators to help operators safely manage load dynamics and ensure stability, as the angle can significantly impact the crane's lifting capacity and balance.