2Ship (Marine) propulsion Mechanism used to move a ship across water (engine turning a propeller)Choice of a suitable powerplant depends on:size of the shipspeed (type of cargo)length, duration of voyagecost (operational expenses)fuel
3Diesel EngineIn 1892 Rudolph Diesel invented the compression ignition engineThe most widely used propulsionTwo-stroke (large engines)Four-stroke (auxiliary e.),.
4Diesel Engine PROS: CONS: most efficient prime mover lower fuel consumptionless bunker spaceCONS:more expensive to build and maintainmore noise and vibrationheavier
5Steam TurbineMarine steam turbine was developed by Sir Charles Algernon ParsonsLow noise, low weight, low maintenance costs, more space obtained (power /weight ratio raised)BUT higher fuel consumption
6Steam TurbineMost 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.
7Diesel electric driveLarge cruiser, tankers, ferries, ro-ro passenger ships and LNG carriersPRINCIPLE1. diesel engine connected to a generator2. Generators drive electric motors3. Electric motors drive the shaft
8Turbo-electric drive PRINCIPLE 1.Turbines generate mechanical energy and drive generatorsGenerators convert mechanical into electrical energy and drive motorsMotors convert back the electrical into mechanical energy and drive the propeller shaft
9Gas 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.
10Nuclear propulsion Submarines, navy ships (air- craft carriers), icebreakers.