Pneumatic Submarine Engines

Hey all Well since my last uploads, I haven't been asleep at the wheel

This is the air engine used for the Aeliopile submarine It can run on steam from the boiler while on the surface, and can be switched to air pressure for diving, without having to stop the engine I didn't show it in this drawing, but there is a way to exhaust the engine into the submarine, that way, while underwater, the engines air exhaust can provide cool breathable air

Both halves of the engines are connected to a differential "head", which ties both engines together, and can drive the two counter-rotating propellers

The engines were built by the Roboro Rowe Brothers foundries in Handsworth Birmingham, circa 1889