Our dockside crane is a Tread Wheel Crane and many pictures of this kind of crane have been found by historians. Some of the Roman illustrations show huge cranes. Romans used them in building and lifting, especially stone. The source of power for these cranes would have been human and where cranes like this were used in quarries and building sites that would mean slaves. Turning the main drum, the winch, would have required many strong folk.
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