How Are Ballast Tanks Filled with Air?
Ballast tanks in submarines are filled with air primarily using compressed air stored onboard.
Submarines rely on ballast tanks to manage their buoyancy and control their depth. These large tanks can be filled with water to increase the submarine's density (making it sink or maintain depth) or emptied of water and filled with air to decrease density (making it surface).
The Process: Injecting Compressed Air
To transition from submerged to surfaced, the water within the ballast tanks must be expelled. This is achieved by introducing a substance less dense than water into the tanks – typically air.
Based on operational principles, compressed air flows from the air flasks into the ballast tanks. These air flasks hold air at very high pressure. When valves are opened, this high-pressure air rushes into the ballast tanks, displacing the water already inside.
Achieving Positive Buoyancy for Surfacing
As the compressed air forces the water out of the ballast tanks, the overall weight of the submarine decreases while its volume remains constant. This reduction in weight relative to the volume makes the submarine less dense than the surrounding water.
- Action: Compressed air replaces water in ballast tanks.
- Source: High-pressure air flasks.
- Result: Overall submarine density decreases.
- Effect: Submarine achieves positive buoyancy and rises to the surface.
This critical process allows submarines to surface safely and efficiently after completing their underwater missions.
