Therefore, as the air on the ballast tanks is released, the tanks will fill in the … Submarine ballast tank By: Raja, Richard and Dhruv Ballast tank Time for a video Conclusion A main system of submarine is a ballast tank . This design allows it to flood the outer hull with water, which causes the vessel to sink, while the crew work and live in the inner one. Well first off… Subs do not use their ballast tanks to alter their depth while submerged. They maintain a neutral Buoyancy and use their forward pr... The submarine ballast tanks now filled with seawater is denser than the surrounding water. How does a submarine ballast tank work? Tanks in Submarines. When fuel from a tank is required, it is forced to the engine room by pumping sea water into the bottom of the tank, the oil passing out through a pipe at the top. The difference in densities between sea water and oil fuel prevents mixing, but involves an increase in weight as fuel is used. And when submarine has to go underwater the ballast tanks are filled with seawater, this makes submarines heavy, so it’s easy for submarine to sink below the surface. @lionfishpatrol: “Neverending submarine work. Screw the cap onto the top of the bottle. Under its strong outer hull are huge ballast tanks that surround its working core. It works like this: when the submarine is above the surface of the water, the ballast tanks are filled with air, which means that the overall density of the submarine is less than the water it displaces. How do submarines get air? >. #lionfish…” These … We pump air … When you see a surfaced sub, all you see is the superstructure. The tanks are linked together via the MBT Blow … The main ballast tanks are part of that superstructure. It's the weight of the seawater that is keeping the sub underwater, so displacing it makes the sub rise to the surface. When the crew is ready to submerge, external ballast tanks that are normally filled with air, open to receive water. In submersibles and submarines, ballast tanks are used to control the buoyancy of the vessel. It operates using the principle of buoyancy by Archimedes. Ballast - submarineboat.com Their primary components are the Main Ballast Tanks which are a series of enormous saddle tanks constructed around the pressure hull of the ship and that are capable of ingesting or expelling tons of seawater to give the submarine either a positive, neutral or negative bouncy allowing it to be either submerged or surfaced.