Which of the following is NOT a common type of crane accident?

The correct response identifies that collisions are not considered a common type of crane accident in the context of the question. Crane accidents typically involve incidents that result from the operational hazards associated with the cranes themselves and their usage.

Cave-ins, which can occur when loads are improperly managed or when ground conditions are unstable, directly relate to the excavation or hoisting contexts in which cranes operate. Tipovers happen when cranes become unstable, often due to improper load distribution or failure to properly set up the crane. Electric lines present another hazard, particularly in terms of electrocution risks when cranes are in proximity to overhead power lines. Accidents involving electric lines can frequently occur if safety protocols are not followed during crane operation.

Collisions, while they can happen, tend to be more contextual to vehicles or equipment interacting with cranes rather than being classified as a direct accident type inherent to crane operation itself. This delineation helps clarify that while colliding with other objects or machinery is a concern when operating cranes, it is the specific risks associated with crane operation—like cave-ins, tipovers, and interactions with electric lines—that predominantly characterize crane-related accidents.