Title Explanations
Cost
Initial
Carbon fiber propellers are more
expensive than bronze props for a one off application if
compared on a like for like basis, but if all other
factors in the table are taken into consideration future
costs and savings out weigh the initial cost.
Quantity
During manufacture of first
propeller a mould is made, this is then reused for future
blade manufacture. The larger the quantity ordered at one
time, the cheaper they are.
Repair
Ease &
Time to repair
Any competent person can replace
a full set of blades for 2 props within half a day.
The propellers do not need to be
sent away, thereby avoiding 2/3 weeks or more out of
commission. This is particularly relevant for a vessel that
may be chartered as a quick replacement of blades can save
the loss of a charter, which in some cases can be many
thousands of dollars
A quantity of spare blades can be
carried for replacement of damaged blades.
Characteristics
Less
weight
Blades are 70% lighter than
conventional bronze propellers, this equates to less
strain on the shaft, p. brackets, cutlass bearings, and
gearbox. This also allows ease of manhandling.
Variable
pitch
The way these props work is very
much like a non mechanical variable pitched prop. With a
standard bronze prop the optimum pitch is at wide open
throttle so as soon as you throttle down the bronze prop
becomes inefficient.
Our props are at their optimum at
all times, hence the flexing. They are highly pitched at
the bottom end, which gives good acceleration and
efficiency and normal pitch at the top end same as the
bronze prop. As the pitch is the same no slippage occurs.
Performance
Acceleration
This is a notable feature of our
Carbon Fiber propellers. There is less propeller weight,
which allows quicker rotation, and optimum bottom end
pitch.
Fuel
economy
Due to optimum pitch better fuel
economy is achieved particularly at 60% to 80% engine
load. Normal cruising can be achieved at less RPM.
Noise
Thinner blade tips are achievable
which makes the Carbon fiber propellers quieter especially
if our seven bladed propeller is chosen.
Emergency usage
Even if the blades are damaged
the boat can still be used, as there is no excessive
vibration of a bronze prop.
Conclusion
Though the one unit cost of Carbon Fiber propellers seem
more expensive than a Bronze propeller for a yacht
builder, where quantities are involved, this is not the
case.
For
an individual one off purchase, the propellers still
have so many advantages over the standard bronze
propellers that such an expense can be justified. They
provide a financial benefit immediately when the props
are installed. Such improved fuel economy, resistance to
impact reducing costs of repairs, reduction in repair
delays, and the ability to replace the blades by a
competent owner or engineer without the need to be sent
away to specialist propeller shops where the turn around
could be between two to three weeks.
For
leisure yachts a swiftly repaired propeller can save a
family vacation, which would normally have to be
abandoned with much upset from friends and family, who
would have taken pre booked time off work. Similarly a
swift change of blades can save a charter and the huge
charter fees involved.
In
the commercial world - time laid up under repair is time
and money lost.
In
our opinion Carbon fiber propellers are already
replacing conventional bronze propellers and it is only
a matter of time before they are the first and only
choice of the builder and commercial operators as well
as individuals.
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