Masting sheer
Ancient sailing ships did not require sheers to erect their masts, as they could be lifted into place by ropes and allowed to pivot around their feet.A crane was needed, tall enough to lift the entire mast vertically and then lower it into the ship.As sheers are not required to move, they were often constructed as masonry towers, with wooden jib structures atop them.Few have survived intact, but some of the towers remain, having now lost their jibs.In the late 19th century, the increasing size and capacity of general harbour cranes began to overlap with the lofty but lightweight masting sheer and so their specialisation was no longer required.
