06PropellerShaftDifferentialNFlywheel.jpg

This is the differential assembly that drives the propeller shaft. The flywheel at the right of the photo would dampen out vibrations from the propeller and also from the pistons used for charging the compressed air tanks. The Brayton Oil Engine is to the left of this area out of view. The engine drew it's air supply from the crew's compartment and vented exhaust directly overboard through a hole in the hull. I can't imagine it running very efficiently with that kind of back pressure in the exhaust. It was planned for the engine to be connected to a compressed air tank, but the Fenian's stole the submarine in a dispute over money before John Holland could add that feature.