Unloading a Column from a Boat with Levers and a Windlass
Great weights borne on levers, held by a wedge at a, then rolled ashore by a windlass
The page treats the safe handling of heavy weights, using the example of a column being taken off a boat. Great weights should always be carried on levers as they are unloaded; a series of sketches shows the column resting on crossed beams, held up by a wedge that supports it by itself at the point a. A cross-section adds an analytical line joining the centres of the column and the transverse pole as the wedge is driven between them. A final sketch shows the column being hauled ashore over beams by a windlass, the cord wound around it as many times as the number of rolls wanted while pulling.
On this page
Support great weights on levers when unloading a boat
Heavy loads such as a column should always be borne on levers as they are taken off a boat, exactly as shown here in the unloading of a column from a boat.
A wedge that supports the load by itself at a
A wedge driven between the column and a transverse pole holds the weight on its own at the point marked a.
Rolling a column ashore with a windlass
A windlass hauls the column up over beams from the boat onto land. You wind the cord around the column as many times as the number of rolls you want it to make while it is being pulled.