How do you do that with a submarine

Submarine technology

Descend and emerge

What makes a submarine a submarine is - as banal as it sounds - the ability to descend and reappear. Submarines have so-called diving and control cells through which they can go on a diving course. Dive cells are special tanks that are filled with water when diving. In this way, the submarine becomes heavier than the water and sinks. The descent can be assisted by operating the depth rudder.

Thanks to the trim cells, which can also be flooded, the center of gravity of the submarine can be shifted and the boat can, for example, sink forward. By pushing the water out of the cells or by pumping out the flooded cells, the density of the boat becomes smaller than that of the water and the boat emerges again.

During the dive, a submarine takes the external pressure conditions with it into the interior of the boat. If it submerges in a low pressure area and comes back to the surface of the water in a high pressure area, the boat sucks in air through the snorkel in order to equalize the pressure conditions.

The diving depth always depends on the pressure that a submarine can withstand. Modern submarines can go to a depth of 250 to 400 meters. Some Russian nuclear submarines have pressure hulls made of titanium and are able to operate at a depth of 900 meters.

A submarine that dips deeper than intended can no longer withstand the water pressure. Its pressure hull would break, the hull would tear and the boat would fill up with water very quickly.

Enough oxygen for use underwater

In a class 212A submarine, there are large oxygen tanks from which oxygen is pumped into the submarine, which supplies the boat with enough breathing air. The exhaled carbon dioxide is converted back into oxygen by a gas mixture. Nuclear submarines filter their oxygen directly from the sea water through electrolysis. If there is enough oxygen and fuel on board, a submarine can operate underwater for several weeks.

Author: Sabine Kaufmann

Status: 08/12/2016, 10:00