You’d think the question, “Who Invented the Screw Propeller?” would have an easy answer. We know who invented the telephone (Alexander Graham Bell), the steam train (Richard Trevithick) and the pop-up toaster (Charles Strite); why not the ship propeller? Well, it seems that the answer is confused because, although the propeller has been around for centuries, the modern day screw propeller was ‘invented’ by several different people at around the same time (like the Calculus, but not really), resulting in an inevitable rush on patents.
Three men came out on top of this scramble, each claiming the modern day screw propeller as their own. Boat propellers were being tested and refined during first half of the 19th Century; the most popular was a long propeller that literally looked like a screw. However, a massive leap in power and efficiency was discovered when, in 1835, one of these screws snapped, leaving something behind that looks much more like a modern day screw propeller. The man who witnessed this and the consequent discovery that this shortened design was far superior, was called Francis Pettit Smith. At around the same time, two men called Frédéric Sauvage and John Ericsson attempted to patent a similar, though not as radical, shortened screw propeller.
Modern-day patenting controversy aside, the propeller as a locomotive principle has been around for centuries. Archimedes’ screw was the first example of a propeller being used for practical purposes, and is one of several important inventions attributed to this 3rd century BC thinker. The Archimedes Screw was used to move water uphill (eg. in the draining of mines, or for the irrigation of crops), using a screw propeller inside a tube. Leonardo da Vinci also sketched a recognisable screw propeller in his design for a helicopter early in the 16th Century.
Even after its patent, the propeller screw was not regularly incorporated into ship design until well into the second half of the 19th Century. Many commentators attribute this eventual acceptance to a famous tug-of-war competition, held in 1845, between the screw-driven HMS Rattler and the paddle steamer HMS Alecto. The Rattler was successful, memorably dragging the Alecto backwards against the insufficient thrust of its paddle power!