how do the ship's propeller moves..? what causes it to move..?

Answer 1

In a typical seagoing ship, oil is atomized and burned in a furnace that contains a bank of hollow tubes filled with water to extract heat energy. The hot water (and steam) circulates to a boiler where the high pressure steam is separated out and passed through a steam turbine that converts the heat energy to mechanical energy. Used steam is exhausted to a condenser that recovers the pure (fresh) water for re-use while lowering the turbine discharge pressure (extracting even more energy) to ingrease overall efficiency. The steam turbine shaft spins at a very high speed and a reduction gear is used to reduce the speed to that required by the ship's propellers. The gearbox in the engine room is connected to the propellers using (lengthy?) shafts that penetrate the stern of the hull through glands that permit rotation while keeping the seawater out. Of course the steam turbine(s) and propellers can be operated at various speeds by increasing or reducing steam flow to the turbine(s) using throttling valves. A special turbine (or set of blades on the main turbine) is used to reverse the propeller to stop or drive the ship astern.

Answer 2

The propellor is mounted to a shaft. The shaft goes through the stern of a ship through a seal that keeps out water, but still allows the shaft to spin. In smaller boats, the seal is usually made of rubber. The water seeping past the seal acts as a lubricant. Water that has seeped past the seal can be collected and periodically removed with a bilge pump. Inside the ship, the shaft is simply connected to the output of a transmission that is driven by a motor. It could be driven by steam, electricity, diesel or gasoline etc.

Answer 3

its coupled to an engines crankshaft via a reduction gearbox.
engine connected to gearbox connected to prpeller shaft connected to hub connected to propeller

Answer 4

It is connectd to an internal combustion engine which turns it much like the wheels of a car.