Ships Atmosphere
The ship contains bulkheads with doors and force fields that can be used to isolate sections of the ship.
Each section of the ship has a 100% atmosphere rating. This can be manually increased to 200%.
Each section of the ship has an armour rating. Typically the outer hull of the ship has an armour rating of 1,000 points. Inner walls have an armour rating of 100. Therefore if enemy fire has stripped away the outer hull, further fire in that area would cause far more extensive damage. Outer hull armour rating can also be boosted by the structural integrity field.
When the armour rating falls to 50 points then there is a hull breach. The atmosphere will reduce at a rate of 1% per second for every point below 50. So if the armour rating falls to 40 points, the atmosphere will drop at a rate of 10% per second. After 10 seconds the atmosphere will be 0.
As sections of the ship’s hull become damaged (breached to space), then the first line of protection is an automatic force field. These force field generators have a health of 100% and operate until the health drops below 25% at which point they fail.
Once the force field fails the next line of defense is the bulk head doors which close to seal off the breached sections. These doors have a health rating of 100% and operate until the health drops below 10%.
Breaches between adjoining sections leak atmosphere through to outer space. Repairing the breach on the outer hull will allow all of the joined sections to be re-pressurised.
In Star Trek: The Next Generation, there are two types of atmosphere on the Enterprise. The navigators are dolphins (never shown in the show, but mentioned). This means some of the sections are filled with water. For our purposes we might want to think about being able to have different atmospheres in different sections so that different species can co-exist happily. This would be a requirement of any true multi-race starship. If you mix atmospheres then things start to get complicated. Obviously if you mix water and normal earth atmosphere it separates out (with water on the floor and Nitrogen/Oxygen floating above it). The same would also happen with two gaseous atmospheres. If you mix a CO atmosphere with Earth atmosphere, the CO will actually flow along the floor as it is heavier. This could get very complex computationally.
Power Requirements
There are no power requirements for the atmosphere. The emergency force fields have self-contained power supplies.