2 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 shipspeed (type of cargo)length, duration of voyagecost (operational expenses)fuel
3 Diesel EngineIn 1892 Rudolph Diesel invented the compression ignition engineThe most widely used propulsionTwo-stroke (large engines)Four-stroke (auxiliary e.),.
4 Diesel Engine PROS: CONS: most efficient prime mover lower fuel consumptionless bunker spaceCONS:more expensive to build and maintainmore noise and vibrationheavier
5 Steam 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
6 Steam 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.
7 Diesel 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
8 Turbo-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
9 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.
10 Nuclear propulsion Submarines, navy ships (air- craft carriers), icebreakers.