Submarines: How They Work - Propulsion
The very first submarines depended on people for the energy to move.
Cornelius van Drebbel, whose submarine was tested on the Thames in 1620 and reported to have carried the King of England on one of its dives, used oars to move itself along. The oars extended from the craft and leather gaskets sealed the point of their emergence.
In the mid-1770s, David Bushnell built a submarine Turtle that used hand and foot cranks for propulsion. This one-person submarine,
which was the first to be used during war, was very inefficient
and exhausted its operator in a short time.
Robert Fulton developed a three-person submarine Nautilus in
the early 1800s that was the first to use diving planes to control depth.
While submerged, it relied on a hand crank to move it along. For travel
on the surface, the Nautilus was equipped with a sail.
Steam & Gasoline Engines
Fulton then tried to build a more efficient submarine using steam. Though the steam engine was actually small, the boiler, which supplied the steam, was large and bulky. Since oxygen was required for the fire, which in turn was required for steam, the submarine had to remain at the surface to operate the engines. To dive, the fires were extinguished and the smokestacks closed. The submarine was left with no power.
In the 1860s, the Confederates built steam-powered submarines, known
as Davids. The name was in reference to the Bible story where David defeated
the giant Goliath. These Davids were made to fight the Goliath Union fleet.
These submarines never completely submerged, but kept their air-intake
pipes and smokestacks above the water's surface. By doing this, the fires
to operate the steam engines never had to be extinguished.
Gasoline & Diesel/Electric
The first submarine in the U.S. Navy, the USS Holland (SS-1),
used a gasoline engine while on the surface and an electric engine while
submerged. The electric engine could recharge while the gasoline engine
was being used.
The electric engine allowed the submarine to travel underwater for a longer
period of time, maybe a few hours, at a decent speed, and it produced
no toxic fumes. The engine was relatively small, but the batteries
were not. They were large, bulky and heavy, and many were required
to supply power to the motor. Since they lost their charge within
a few hours, the submarine would have to return to the surface often
Batteries presented other problems, since they emitted toxic fumes when contaminated
with seawater, and they always contained dangerous acids.