Ship’s wheel
The ship wheel was one of the most significant mechanical improvements to ship design during the 18th century, and a great advance on the whip staff that preceded it. The whip staff was connected to the tiller, and that with the rudder, that moved the rudder when the whip was moved by the coxswain.
A whipstaff is a device used in 16th/17th century Europe to control the movement of a large sailing ship, Illustration from Ship & Ways of Other Days by Edward Keble Chatterton, 1913
The invention of the ship’s wheel is credited to the Royal Navy but there is no hard evidence to support this. What is clear is that the ship’s wheel did not become commonplace until around 1715. Early wheels were placed behind the mizzenmast, which obstucted the coxswain’s (helmsman) view. They were designed to have two men operating them during heavy weather, although the small amount of space around the wheel caused the sailors to get in each other’s way.
It wasn’t until 1740 that ships were fitted with two wheels on a single spindle at either end of a drum winch, which allowed four men to steer when conditions were bad. These first wheel systems suffered from a lack of equal amounts of tension when the ropes were at their extremity, making steering something of an imprecise art. This flaw remained for 70 years until a man named Pollard, master shipwright at the Portmouth Dockyard, introduced sweeps and rowles into the system. This new system was tested by Captain Bentinck in 1771 and proved such a success that it became the standard on all Royal Navy ships by 1775.
A ship’s wheel is composed of eight cylindrical wooden spokes shaped like balusters, each joined with a barrel, which houses the axle, so the tiller rope or chain (sometimes called the steering rope or chain) was wrapped in five or six loops arround it and led below deck and from there to a pair of pulleys before coming back together and connecting to the rudder. As the wheels moved, the rudder swung in the desired direction. This means that if the coxswain turned the wheel to the left (port),the tiller would go to the right (starboard) but the rudder would also turn to the left and steer the ship in that direction.