SHIPS’ propellers could be about to undergo their biggest transformation since Brunel’s SS Great Britain, the first large iron-hulled ship with a screw propeller, was launched more than 150 years ago. Sea trials have shown that replacing a conventional metal propeller with one made of carbon composite can help reduce corrosion and maintenance, and make warships stealthier.
Propellers are normally made from an alloy of nickel, aluminium and bronze (copper and tin), known to marine architects as NAB, while the hull is usually steel. Putting the two in seawater causes a current to flow – just as in the school…
