Page 78 - Vetus

PROPELLERS

The most essential component of your boat
VETUS makes good use of an especially developed computer programme, which determines exactly the right propeller for your
boat. The most important elements of propeller design and manufacture are balance, dimensions, material and the blade area.
1. If you bear in mind that a propeller is often rotating at 2.000 r.p.m. (more than 30 revolutions per second), you will understand
that it is an absolute must that a good propeller is well-balanced.
2. In order to achieve the best performance and to minimize vibration, it is extremely important to ensure that the pitch of each
blade is identical and that the distance between the blades does not vary. This requires great manufacturing precision.
3. VETUS propellers are made of manganese bronze, an extremely resilient, yet flexible material.
4. The choice of a good propeller with all above combined qualities, is of the utmost importance.
5. A propeller specialist must always determine the diameter and pitch and the required (fixed) Fa/F ratio. This means the total area
of the propeller circle (F) in comparison to the surface area (stretched and developed) of all blades (Fa). The choice of the Fa/F
ratio is dependent on the shape of the underwater section and the speed of the boat in question.

3-Bladed propeller 3-Bladed propeller
Type P3B Type P3C

P3B P3C

oude kleuren:
c o
m 30,2
y 100
k 30,2
Fa/F = 0,52
H = 0,43 D
Fa/F = 0,55
H = 0,45 D
oude kleuren:
c o
m 30,2
y 100
4-Bladed propeller k 30,2 4-Bladed propeller
Type P4E Type P4G
P4E P4G

Fa/F = 0,69
Fa/F = 0,85
H = 0,43 D Fa/F = 0,85
H = 0,5 D
H = 0,5 D

78 Stern gear systems - Want to know more? Visit www.vetus.com