posted on Jan, 9 2007 @ 05:32 AM
I'll go over a few things for basic submarine operations and the differences
between nuke and non'nuc-diesel submarines.
Diesel submarines use diesels as the primary generators and propulsion of their boat. They are electrically driven by main motors that turn the
shaft, which is powered either by the diesel or by the onboard large batteries. Generally they drive on the diesels for power when shallow, on the
surface, or when charging batteries. The diesels, depending on the type of submarine can be quiet or very noisy, it also depends on the amount of
background noise and where it drags the sound on how hard it is to find them. A diesel boat on the battery is generally very quiet, but they are
limited to slow speeds and have a submerged limited time based upon the type of batteries or other type of propulsion system they have installed.
Almost any submarine is detectable if it is operational, you just have to have the right equipment to find it, and good watchstanders.
Based upon the type of submarine, most can operate submerged at a shallow depth and recharge the batteries, but it is loud. AIP- Air Independant
Propulsion types of submarines use variants on the diesel to support extended submerged operations. IE, some use hydrogen, hydrogen peroxide, hydrogen
fuel cells, and others use electrolytic units to make hydrogen and pure oxygen. This means they can run the diesels at deeper depths and less noise
without being shallow.
A nuclear submarine requires none of this to operate. They can freely operate at any depth. Depending on the country type, they have different noise
signatures based upon the technology of the country that built them. Some countries have been very good at quieting versus a diesel. I have seen some
submarines that are near undetectable at range, both nukes and diesels.
One thing to remember, when submerged, the water is a near perfect transmitter of sound. What to look for in the ocean? Mechanical sound, any type
of it is transmitted very well. If you put your head underwater and slap the top of the water, you get a pounding, most can measure the doppler affect
of the sound and tell how far away that sound was transmitted from it.
Near anything operating near the surface on the ocean can be heard by most submarines. IE a helo that is near the surface, they can count the rpm of
the rotor and still hear them drop a buoy used to counterdetect them.
A simple hammer dropped on the wrong deck of a submerged submarine can be heard up to hundreds of miles. Mechanical noise......anchor chains, buoys,
many things are picked up.
Submarine science, it is an amazing thing.