>yes they seem very dangerous in comparison to a fixed-base crane. I think this is a rather baseless assumption. Properly engineered and planned lifting from a

>yes they seem very dangerous in comparison to a fixed-base crane. I think this is a rather baseless assumption. Properly engineered and planned lifting from a mobile crawler crane should be inherently no riskier than that from a fixed crane. Lifts from both fixed-base and crawler cranes are subject to operator error and maintenance-related risks. My experience is limited to very big cranes on ships (both fixed and crawler) where everything is engineered and planned to (speculating here) a much higher degree. Maybe it's not comparable to the typical (smaller) construction cranes you see in cities.