The intend is to visualize the learners with the mechanism of propulsion system of a ship & various types of propellers used.

1. PROPULSION SYSTEM
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2.  A marine propulsion system may be defined as
the mechanism by which a thrust force is
produced to propel the ship/boat across water.
 The vessel moves forward when the produced
thrust overcomes the drag or resistance of the
hull form in water.
 Today ship propulsion is not just about
successful movement of the ship in the water. It
also includes using the best mode of propulsion
to ensure a better safety standard for the marine
ecosystem along with cost efficiency.
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3. TYPES OF PROPULSION SYSTEM
 Diesel Propulsion
 Diesel-electric Propulsion
 Nuclear Propulsion
 Gas Turbine Propulsion
 Steam Turbine Propulsion
 Water-Jet Propulsion
 Solar Propulsion
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4. CONVENTIONAL DIESEL PROPULSION
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6. THE SCREW PROPELLER - GEOMETRY
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8. Fixed-Pitch Propeller
 Most propellers are fixed-pitch or mono-block propellers.
They are cast in one piece and the blades are fixed to the
hub.
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10. Controllable-Pitch Propeller
 In Controllable-pitch propeller, the pitch of the blades can be
changed by a hydraulic mechanism in the hub. The hub of
a CPP is of course more complicated and expensive. The
hub diameter is also larger than that of a FPP, which
reduces the efficiency.
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12. Ducted Propeller
 The propeller is surrounded by a shroud or duct usually in the
form of an axi-symmetrical (annular) aerofoil with a very small
gap between the propeller blade tips and the internal surface of
the duct.
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14. Azimuth Thrusters
 Thrusters are propellers which are used at very low speeds
or in bollard conditions. The loading of a thruster is often
high, so ducted propellers are used. A typical characteristic
of a thruster is that it can rotate about the vertical axis, thus
making a rudder superfluous. Thrusters are applied in a
wide range of applications, e.g. in dynamic positioning.
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17. Podded propellers (Azipod)
 A more or less logical development from the Z-drive
propeller is the podded propeller.
 In this case the drive engine is directly connected to the
propeller shaft and is located in a pod outside the hull. This
is only possible when electrical propulsion is used. The
generators and diesels can then be arranged in the hull on
convenient locations.
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19. Pump Jets (Water Jets)
 The basic mechanism of propulsion is the acceleration of
water. This cannot only be done by e.g. a propeller outside
the hull but also inside the hull.
 A pump jet or water jet is a pump in the hull which takes
water in at the inlet in the bottom of the ship and
generates a high speed jet at the outlet. The outlet is
generally above the water to minimize the pressure at the
exit.
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20.  The water jet has excellent steering characteristics because
downstream of the nozzle, the jet can be diverted in any
direction. This is done by steering the nozzle in a certain
direction using hydraulic cylinders. For braking and astern
thrust a cap is used which causes thrust reversal by
reversing the jet direction.
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21. Voith Schneider Propeller
 A Voith Schneider propeller is typically a vertical axis
propeller and consists of a series of vertical blades set into a
horizontal rotor, which rotate about a vertical axis. The rotor
is flushed with the bottom of the ship and blades projected
down.
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23. Bow Thrusters
 It is useful for maneuvering ship in confined waters at low
speeds. A popular arrangement for this in the ships involves
a cylindrical duct passing through the ship from side to
sides, in which is fitted an impeller which can produce a
thrust to port or starboard.
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