Teignbridge Propellers, near the seaside town of Torquay on England’s south coast, has been designing and manufacturing propellers and stern gear for half a century. Having started out serving commercial ships and workboats, Teignbridge also operates at a higher level with military vessels and large yachts. It’s one of few such companies with its own foundry, and its manufacturing takes place in a historic brick building built by Isambard Kingdom Brunel, the great civil and mechanical engineer. Aptly, Brunel also designed the SS Great Britain, the first propeller-driven, iron-hulled ship to cross the Atlantic, in 1845.
Today, marine propellers come in every shape and size, but they all convert rotational motion into thrust by producing a pressure difference in the surrounding water. Historically, their design has been driven by trial…