USS COD Articles - Air Systems


The compressed air system is one of the most important systems on the submarine. It is used to blow the ballast tanks, fire torpedoes, pressurize the hydraulic system and to start the main engines. The air system is necessary for the submarine to dive, surface, cruise, and attack. One of the highest priorities upon surfacing is to replenish the compressed air store.

There are five separate air systems on the submarine:

3,000-pound high-pressure and torpedo impulse system. This system consists of the compressors, high-pressure air manifold, interconnecting piping, valves and compressed air storage banks. The main function of this system is to compress, store and supply 3,000 psi air for use within the 3,000 pound, the 600 pound, and the 225 pound systems. This system also supplies air to charge the hydraulic accumulator and to the 600 pound reducers which supply air for the torpedo impulse manifold. This system also has an external charging connection so that it could be supplied with air from an outside source.

600-pound main ballast tank blowing system. This system is supplied by the 3,000 pound system and is used to blow water ballast from the main ballast tanks during surfacing of the submarine.

225-pound service air system. Supplied by the 3,000 pound system, the service air system is used to supply air for all the miscellaneous services aboard the submarine.

10-pound main ballast tank blowing system. This system is independent of the first three and is supplied by a Roots-type blower located in the pump room. It is used to conserve the stored compressed air and is used only when the submarine is on the surface after the main air induction valve is opened.

Salvage air system. This system consists of external and internal systems. The external systems allow flooded compartments or tanks to be blown with air from an external source, such as a rescue ship. The internal system uses ship's air and is used for compartment salvage only.

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Last revised 09 April 2009
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