What else was the high-pressure air used for?

High pressure air was used for many purposes on the boat. It was used to:

1. Charge the air flasks in the Mark 14 steam torpedoes to 2,800 PSI.
2. Blow the water out of the main ballast tanks to surface. The air was stepped down to 600 PSI for this purpose.
3. Launch torpedoes from the tubes. The air was stepped down to 300 PSI for this.
4. Roll over the diesel engines to start them. The air was stepped down to 50 PSI.
5. The air could be bled into the boat if needed when the oxygen content got too low or the CO2 content got too high. This pressurized atmosphere inside the boat somewhat and the air was far from fresh. However, it supported life.