In a submarine, there is a device called ballast tank. A ballast tank is a type of machine that has a pump and a few other machines. The pump is the most essential part of the ballast tank. For a submarine to sink. the pump will 'suck'in water, and air will be forced out, increrasing density and weight and thus sinking.to float back up, the pump, instead of taking in water, takes in air and water wil thus be given out.This is a picture of a ballast tank and how it floats and sinks.

During a journey, the submarine must maintain the same amount of composition of water and air. This is called nuetral buoyancy.


This is a diagram of a submarine.It shows all the machines in a submarine.












A Submarine HIstory
submarine name:kursk

Work on building the Kursk began in 1992 at Severodvinsk, near Arkhangelsk. Launched in 1994, it was commissioned in December of that year. It was the last of the large Oscar-II class submarines to be designed and approved in the Soviet era. At 154m long and four stories high it was the largest attack submarine ever built. The outer hull, made of high-nickel, high-chrome content steel 8.5 mm thick, had exceptionally good resistance to corrosion and a weak magnetic signature which helped prevent detection by Magnetic Anomaly Detection (MAD) systems. There was a two-metre gap to the 50.8 mm thick steel inner hull.It was indeed an maginficent submarine.

Unfortunatly,tragedy struck.An explosion occurred while the Kursk was preparing to fire Dummy Torpedoes.The only credible report to date is that this was due to the failure and explosion of one of the Kursk's hydrogen peroxide-fuelled torpedoes. It is believed that HTP, a form of highly concentrated hydrogen peroxide used as propellant for the torpedo, seeped through rust in the torpedo casing.

It is also believed that a chemical cartridge ( potassium superoxide), had also been the cause of death. It came in contact with the water that had caused chemical reactions and flash fire.

Which of these really happened? No one knows for sure.

However, a second explosion occured, reading 3.5-4.4 on the Ritcher Scale.


Fortunately, 23 sailors out of 118 sailors had survived the first explosion. Captain Lieutenant Dmitry Kolesnikov, one of the survivors of the first explosion, had written notes about his stay and confirmed there were other people with him as well.The rest died in the next explosion that happened a few hours later.

The world was shaken when they had heard this devastating news.But it has already happened. We can only remember those brave people in our hearts.

My condolences.



Question Alert 1:If a submarine lands on the seabed, why is it unable to float and move once more?

My answer is that maybe when the submarine has reached the seabed, the propeller has been crushed in the process. But that seems highly unlikely as i doubt it happens everytime.

Please give me your thoughts for Question Alert 1. Gracias~

29 jan 09: Mr Lim had said the submarine moved by thrusting forward. As the seabed is rough, the submarine cannot move and so the upward thrust cannot be used.

Rachel