Advance Ship Resistance & Propulsion – LNB 21103
- Propeller Making -
MOHD SYAHMI NURUDDIN
ROZAIDI CHE RAZIB
• Finnscrew Sdn.Bhd is a company
that produce propeller for boat and
• Head office base at Finland.
• One of their factory for propeller
making was located at Ipoh,Perak.
• They produce all type of propeller
with different size and materials.
• 9 step which are:
– Pattern making
– Surface finishing
– Packaging and shipping
• Pattern making is a process where
from the design, the make a
propeller blade template.
• The blade section is made from
fiber glass and Putty.
• Molding is a process to make a
mould to get propeller shape.
• It have 2 section which are upper
section and lower section.
• The mould was made from fine
sand and hardener agent.
• Casting is a process where a
melting of propeller material such as
Manganese Bronze will be put into
mould to form a shape of propeller.
• Fatling is a process where the
product of propeller will be removing
from the mould.
• Process to remove the abundant
part and drill the boss to make a
hole on Hub/Boss.
• To ensure that the blade angle is
correct and follow the design.
• They use a template to check the
• At finnscrew sdn.bhd, they use static
• The propeller will attach to a steel
rod. Then,it will put on a roller table.
• If there have unbalance weight of
blade, the more weight part will goes
• Worker will grind that part to reduce
the weight to get balance with other
• After balancing process had done,
the propeller will going into grinding
section again for surface finishing.
• They use sand paper grinding disc
to smooth the surface.
PACKAGING & SHIPPING
• After surface finishing, the propeller
is ready for packaging. They put it
into wood box and cover it with
• Then, it is ready for export to Europe
• Quality is important thing for each
propeller to ensure that the propeller
is following the rule of IMO. The
material must be following the
standard of Shipping Classification
Society to make it safe, reliable and
• To ensure all of this happen, the
company was use a special
equipment to check the material
content. A piece of product will be
use for analysis.
• Computer will analyze the content
before display it onto monitor
• Engineer will read the data and
compared it with the manual spec for
propeller that which type they built.
• There are two methods of propeller
– Static balancing
– Dynamic balancing
• Static unbalance is gravity at work.
• If a propeller is placed between
centers on frictionless rollers the
heavy or weighted portion will rotate
to the bottom immediately.
• This is corrected by adding or
removing weight from the propeller.
• Dynamic balancing of a propeller is
done to provide for the lowest level
of vibration in its operating range.
• Professional Dynamic Balancing
use sensors to provide data to a
digital processor during brief engine
runs at 2000-2400rpm.
• Corrective weights measured to the
1/10th gram are temporarily placed
under spinner screws or starter ring
gear which is measured to ± one
• Cavitation is defined as the
phenomenon of formation of vapor
bubbles of a flowing liquid in a
region where the pressure of the
liquid falls below its vapor pressure.
• Cavitation calculates by using Euler
• The Euler number is a
dimensionless number used in fluid
flow calculations. It expresses the
relationship between a local
pressure drop e.g. over a restriction
and the kinetic energy per volume,
and is used to characterize losses in
• Somewhat the same structure, but
with a different meaning is the
• The Cavitation number is a
dimensionless number used in flow
calculations. It expresses the
relationship between the difference
of a local absolute pressure from
the vapor pressure and the kinetic
energy per volume, and is used to
characterize the potential of the flow
• Podded propulsion is a marine
propulsion units consisting of
electrically driven propellers
mounted on a steerable pod. It is
also known as azipod (Azimuth
Podded Propulsion System).
• The pod's propeller usually faces
forward, as in this puller (or tractor)
configuration, the propeller is more
• In addition, because it can rotate
around its mount axis, the pod can
apply its thrust force in any
• Azimuth thrusters allow ships to be
more maneuverable and enable
them to travel backward nearly as
easily as they can travel forward.
• The Azipod concept is not practical
for use on warships because of
damage control difficulties;
integrating propulsion with rudder
makes both easier to damage or
• In the traditional azimuth propulsion
system the (electric) motor is
located inside the ship's hull and
rotation is transferred to the
propeller through a gearbox.
• In the Azipod system the electric
motor is installed inside the pod.
The propeller is connected directly
to the motor shaft. No gearbox is
required, thus providing greater
• Electric power for the Azipod motor
is conducted through slip rings that
allow the Azipod to turn through 360
• Because fixed pitch propellers are
used in Azipods, power for Azipod is
always fed through a variable-
frequency drive that allows speed
control of the propulsion motor.