A crane with variable angle booms shall be equipped with a boom angle indicator, readily visible to the operator. A crane with telescoping booms shall be marked or equipped with a device to indicate clearly to the operator at all times the boom's extended length. Except for an electric crane, the load line hoist drum shall have a system or device on the power train, other than the load hoist brake, that: Regulates the lowering rate of speed of the hoist mechanism; and Prevents free fall. An electrical crane shall meet the requirements of 29 CFR §1910.179(f)(1), (2), and (3)(ii). Damage Prevention Device. A crane and hoist shall be equipped with a: Positive acting device, such as anti-two block, which prevents contact between the load block or overhaul ball and the boom tip; or System, such as a two block damage prevention feature, which deactivates the hoisting action before damage may occur to the load block, overhaul ball, or boom tip.