SHIP PROPULSION

Ship (Marine) propulsion Mechanism used to move a ship across water (engine turning a propeller) Choice of a suitable powerplant depends on: size of the ship speed (type of cargo) length, duration of voyage cost (operational expenses) fuel

Diesel Engine In 1892 Rudolph Diesel invented the compression ignition engine The most widely used propulsion Two-stroke (large engines) Four-stroke (auxiliary e.) ,.

Diesel Engine PROS: CONS: most efficient prime mover lower fuel consumption less bunker space CONS: more expensive to build and maintain more noise and vibration heavier

Steam Turbine Marine steam turbine was developed by Sir Charles Algernon Parsons Low noise, low weight, low maintenance costs, more space obtained (power /weight ratio raised) BUT higher fuel consumption

Steam Turbine Most new-build ships with steam turbines are specialist vessels such as nuclear-powered vessels, and certain merchant vessels (LNG, coal carriers) where cargo can be used as bunker fuel.

Diesel electric drive Large cruiser, tankers, ferries, ro-ro passenger ships and LNG carriers PRINCIPLE 1. diesel engine connected to a generator 2. Generators drive electric motors 3. Electric motors drive the shaft

Turbo-electric drive PRINCIPLE 1.Turbines generate mechanical energy and drive generators Generators convert mechanical into electrical energy and drive motors Motors convert back the electrical into mechanical energy and drive the propeller shaft

Gas turbine A compressor draws in and compresses atmospheric air. A combustion system where fuel is injected, mixed with compressed air and burned. Power turbine to the shaft. Poor thermal efficiency at low power.

Nuclear propulsion Submarines, navy ships (air- craft carriers), icebreakers.