The Mechanism of a Submarine
Submarines can operate underwater without any electricity to make them sink to the bottom and rise to the surface of the water. A submarine has large tanks called ballast tanks onboard that control how deep the submarine sinks or how high it rises. To sink, the tanks fill with water. A large the amount of water in the ballast tank causes the submarine to sink. Less water in the tanks cause it to sink less. To raise the submarine, the water is released from the ballast tanks and compressed air (that is kept onboard in flasks) is let into the ballast tanks. The more compressed air that is added the more the submarine rises. If a lower the amount of compressed air is pumped into the tank, the sub will not rise as much. Carbon dioxide must be released from the submarines because it rises and becomes a toxin. There must also be a balanced amount of oxygen for the crew onboard to breathe!
Why were submarines built?
Submarines were first designed and built because enemies in wars could see boats that were above the surface of the water. The navy wanted to go underwater and drill holes in the bottoms of ships, attach dynamite to ships, and creep up without a country knowing. Then they could invade and have a great advantage in winning battles. Eventually submarines held bombs such as torpedoes, which were launched from the submarine!
How were submarines designed?
The first submarine was built in the 1500ís. It was a sealed ship that wasnít fully able to go underwater. It had oars that stuck out of leak-proof holes on the sides of the body of the submarine (which did go underwater). The crew inside rowed with the oars. It was a success, but it was still seen above water so eventually techniques got better. Finally, submarines could rise and sink with ballast tanks, but they werenít equipped with tools that could destroy the enemy in war. Next, compartments were built to hold torpedo bombs, drills, dynamite and more.
Transportation for Crew
The crew on board could live in the submarine for months or even years at a time! They had small sleeping, cooking, dining and bathroom areas, which they used to sleep, cook, dine, brush their teeth etc. Everything was very small and a bit of a squeeze, so most of the crew would stop for breaks when they could.
"Learn How a Submarine Dives and Surfaces." Carnegie Science Center. 13 December 2004 <http://www.carnegiesciencecenter.org/exhibits/dive-surface.asp>.
"Evolution of Submarines." Carnegie Science Center. 11 December 2004 <http://www.carnegiesciencecenter.org/exhibits/sub-evolution.asp>.
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