Towards Diesel-Electric Propulsion

 

 

One of the greatest limitations of early submarines was the lack of a suitable means of propulsion. In 1880, British clergyman George W. Garrett successfully piloted a submarine using steam from a coal-fired boiler with a retractable chimney. Although the fires had to be put out before the vessel sank (otherwise the submarine would run out of air), enough steam remained in the boiler to propel it several miles underwater.

 

Similarly, Swedish weapons designer Torsten Nordenfeldt designed a steam-powered submarine with twin propellers. His boat could be immersed to a depth of 50 feet using a vertical propeller and had one of the first practical torpedo tubes. Several countries built submarines based on Nordenfeld's design. To solve the propulsion problem, two French naval officers built Le Plongeur, a 146-foot-long submarine with an 80-horsepower air engine, in 1864. However, the ship's air tanks were quickly exhausted with each voyage. The development of electric motors finally made electric propulsion practical.

 

The Nautilus submarine, built by two British men in 1886, was an all-electric boat. The Nautilus was powered by two 50 horsepower electric motors powered by a 100-cell battery, achieving a surface speed of 6 knots (nautical miles per hour, 1 knot being equivalent to 1.15 land miles per hour or 1.85 kilometers per hour). However, the batteries required frequent charging and overhauling, and the vehicle could not travel more than 80 miles without recharging. In France, Gustave Zéde introduced the Gymnauto in 1888. It was also powered by an electric motor and was very maneuverable, but had a tendency to spin out of control while submerged.

The late 19th century was a period of intense submarine development, and Zéde collaborated on several designs that were supported by the French Navy. The most successful French underwater vehicle of this period was the Narval, designed by naval engineer Maxime Laubeufe. Launched in 1899, the Narval was a 34-metre long catamaran boat powered by a steam engine on the surface and an electric motor underwater. Ballast tanks were placed between the catamarans, a concept still used today.