James Lybrand - Silent running
Any diesel electric submarine is comprised of a number of components. In the drive train, there is a diesel engine, like a prime mover in a large truck, or a locomotive, which then goes on to an electrical generator to provide power. The power does two things, it provides what's called hotel load, to run all the components, internal lights and fixtures and fittings and charge the batteries and the batteries are a lead acid battery, like your normal car, however, they're very big.
And for Collins, there's four separate battery sections, each of which has just got 99 cells, but the voltage in those is quite low, unlike a car which is about 12 to 13.6 or 14.2 volts. The nominal voltage of a Collins cell is only sort of in the order of 1.5 to sort of two point something volts. So the connection between those batteries is to the main motor as well.
And the main motor is an electric motor just like what's in a slot car to make that as easy as possible to direct current and for Collins it's two motors on the same shaft and the combination of how you electrically connect those batteries and those motors together, either in series or parallel, gives you different abilities to create more revolutions and more speed out of the submarine in the back and the shaft of the submarine comes out the back of those two electric motors. So when you're running on batteries, it is nearly silent. Even if you stand right next to the shaft you can hear almost nothing.