# [2014] Ryan Nixon: Down Periscope

In Glogpedia

Last updated 6 years ago

Discipline:
Science
Subject:
Engineering

Down Periscope

Submarines are able to sink and float in part by ballast tanks. These tanks are able to store seawater inside the submarine by opening valves in the submarine. When opening the valves, seawater fills the tanks and adds mass and density to the submarine, allowing it to sink.

Although some submarines may weigh many tons, they are still able to float in water. In order to get a submarine to float, you must clear the ballast tanks of water. Compressed air is used to force the seawater out of the submarine and decrease the mass and density, making it float to the surface.

Submarines use nuclear engines to power their propultion in the water. The engines turn mechanical energy into electrical energy by first generating heat from the fissioning of nuclear fuel. Steam is made from the energy in the fissioning to vaporize pressured water pumped into the nuclear engine. The steam then turns the turbine, which turns the generator and makes electricity that is used to propel the submarine.

This diagram resembles a normal submarine and where its "rooms" are commonly placed. Almost like an exoskeleton of an insect, the pressure hull (not labeled) is a strong metal formation around the submarine that protects the people in the submarine from the pressure of the water around it formed by gravity against the bouyant force in deep depths and possible weapon fire to the submarine.

The diagram on the left shows the three types of bouyancy. The positive, neutral and negative bouyancies against the opposing gravity play a large part in the sciece behind submarines because if the submarine weighs less or equal to the amount of water displaced, then it will float. If more water enters the ballast tanks, it increases the mass of the submarine, which will cause it to hover or sink. This would create neutral or negative bouyancy.

An objects density determines whether it sinks or floats in a liquid. Then, how does a submarine change its density to sink or float in water?

By Ryan Nixon and Garrett Cook