WHAT IS THE PURPOSE OF A BOW THRUSTER ?
When manoeuvring a boat, at low speed, the required control of the movements
of the boat, especially those of the bow, is extremely difficult to achieve. In
such cases, a bow thruster is the solution to the problem. Even when the boat is
not under way, complete control of the movements of the ship's bow can be
achieved by operating the bow thruster.
POINTS FOR ATTENTION WHEN SELECTING THE CORRECT BOW THRUSTER
It is the thrust of a bow propeller, not the output of its electric motor
(in kW or hp), which determines its effectiveness. This thrust is the result of
the following combined factors: power of the electric motor, the propeller
(shape, dimensions and number of revolutions) and the efficiency losses in the
tunnel. VETUS bow thrusters have a thrust of 15 to 22 kgf per kW of the electric
motor. Compared with this, other bow thrusters have been introduced on the
market with an effective thrust of no more than 4 kgf per kW! (kgf=Kilogram
force, kW=Kilowatt)
THE PROPELLER
VETUS uses plastic propellers, which cannot corrode. Owing to their low
weight, the maximum thrust force is obtained very quickly and with minimum use
of energy. The propeller blades are shaped in such a way, that the thrust is
equal in either direction. The are also designed with a special view to
being used inside a tunnel, thus avoiding cavitation (= unwanted noise!).
THE TUNNEL
The smaller the diameter of the tunnel, the less resistance it will cause when
under way. In addition, a smaller diameter also allows the tunnel to be
installed further forward which enhances the turning moment of the boat. VETUS
has obtained the optimum compromise between high efficiency of the bow thruster
and low resistance when the boat is under way.
For vessels made of steel, aluminium and g.r.p., VETUS offers steel, aluminium
or g.r.p. tunnels.
THE TAIL PIECE
Application of a streamlined tail piece by VETUS not only ensures a better
efficiency through lower resistance but also a lower noise level. Disturbance of
the free flow of water through the tunnel, caused by a non-streamlined tail
piece, results in cavitation or, in other words, unwanted noise! In order to
protect the bronze tail piece against corrosion by electrolysis, a zinc anode
(fitted or separate) is standard with each VETUS bow thruster. The transmission
inside the tail piece uses bevel gears, which produce far less noise than chain
transmission.
THE ELECTRIC MOTOR
In order to ensure the highest possible efficiency and longevity, VETUS has
specified electric motors, which are constructed for use as bow thruster motors.
In contrast with modified starter motors, these VETUS motors allow continuous
running for several minutes.
INSTALLATION POSSIBILITIES
The motor of the VETUS bow thruster may be installed in any position i.e.
horizontally as well as vertically. Yet make sure that the motor is positioned
above the propeller at all times.
WHICH FACTORS WILL AFFECT THE THRUST
EFFICIENCY ?
The nominal thrust force can only be obtained under optimum conditions and the
following factors will influence the efficiency in a negative sense:
• low voltage at the motor, due to reduced battery voltage or excessive voltage
drop through the battery (main supply) cables.
• when the tunnel/hull connection is not made in the best possible way; in other
words: the shape of the tunnel openings is a discerning factor.
• when the tunnel openings are provided with grilles.
THE STERN THRUSTER
All VETUS bow thrusters may also be used as a stern thruster (at the rear of the
boat). This will again enhance the manoeuvring capabilities considerably.
Advantages of VETUS bow thrusters
- A single propeller creates less flow disturbance in the
tunnel
- The VETUS unique propeller blade design minimises
cavitation noise
- Spiral gears minimise transmission noise
- The use of a flexible coupling between tail piece and
motor eliminates vibration
- All VETUS systems use a streamlined tail piece for
optimum flow
- A strong synthetic propeller eliminates corrosion and
reduces weight
- Systems are easy to install, supplied with clear
installation and operation instructions
- VETUS systems use a new line of high quality aluminium
control panels which are interchangeable with older panels
- All VETUS manoeuvring systems meet the EMC requirements
A bow thruster is an electrically or
hydraulically driven laterally operating propeller, which enables the bow of a
boat to move sideways. By simply operating the controls, the bow of the vessel
will move to either port or starboard. In a similar manner, the stern of the
boat can also be controlled, by installation of a VETUS stern thruster. It goes
without saying that a VETUS bow and/or stern thruster will considerably enhance
the manoeuvrability of a boat in marinas and locks, particulary when there are
strong winds and currents!
Technical data
|
55 lb / 2512D
|
77 lb / 3512D
|
121 lb / 5512D
|
132 lb / 6012D
|
165 lb / 7512D
|
210 lb / 9512D
|
276 lb / 12512D
|
352 lb / 16024D
|
488 lb / 22024D
|
627 lb / 28548D
|
Motor
|
Reversible DC Motor
|
Reversible DC Motor
|
Reversible DC Motor
|
Reversible DC Motor
|
Reversible DC Motor
|
Reversible DC Motor
|
Reversible DC Motor
|
Reversible DC Motor
|
Reversible DC Motor
|
Reversible DC Motor
|
Power KW (hp)
|
1.5(2)
|
1.5(2)
|
3(4)
|
3(4)
|
4.4(6)
|
5.3(7.5)
|
5.3(7.5)
|
7(9.5)
|
11(15)
|
16(21.5)
|
Thrust (lb)
|
55
|
77
|
121
|
132
|
165
|
210
|
275
|
352
|
485
|
628
|
Tunnel Diameter
|
4 11/32
|
5 29/32
|
5 29/32
|
7 9/32
|
7 9/32
|
7 9/32
|
9 7/8
|
9 7/8
|
11 13/16
|
11 13/16
|
Weight excluding tunnel (lb)
|
22
|
26
|
44
|
48
|
57
|
66
|
81
|
101
|
150
|
150
|
Voltage 12V
|
|
|
|
|
|
|
|
|
|
|
Current, Amps
|
200
|
205
|
350
|
280
|
500
|
610
|
800
|
|
760
|
|
Operating Time (min)
|
4
|
4
|
4
|
5
|
2
|
3
|
2.5
|
|
2.5
|
|
Main fuse, Amp
|
125
|
160
|
250
|
200
|
300
|
425
|
500
|
|
500
|
|
Batteries min Ah/Max. Ah
|
1x55/1x70
|
1x55/1x70
|
1x108/1x165
|
1x70/1x120
|
1x143/2x120
|
1x65/2x143
|
1x225/2x225
|
|
2x200/ 4x165
|
|
Battery cable ft/AWG
|
0-37/2
|
0-38/2
|
0-40/00
|
0-31/1
|
0-27/00
|
0-37/0000
|
0-28/2x0
|
|
0-63/0000
|
|
Battery Main Switch
|
75
|
75
|
100
|
100
|
250
|
250
|
600
|
|
600
|
|
Voltage 24V
|
|
|
|
|
|
|
|
|
|
|
Current, Amps
|
|
|
200
|
140
|
280
|
320
|
450
|
540
|
|
560
|
Operating Time (min)
|
|
|
4
|
5
|
3
|
3.5
|
2.5
|
4.5
|
|
2.5
|
Main fuse
|
|
|
125
|
125
|
160
|
200
|
250
|
355
|
|
355
|
Batteries min Ah/Max. Ah
|
|
|
2x55/2x70
|
2x55/2x70
|
2x70/2x143
|
2x110/2x143
|
2x108/2x200
|
2x143/4x120
|
|
4x143/8x120
|
Battery cable ft/AWG
|
|
|
0-73/2
|
0-57/4
|
60/1
|
0-59/1
|
0-64/00
|
0-85/0000
|
|
0-136/000
|
Battery Main Switch
|
|
|
75
|
75
|
100
|
100
|
250
|
250
|
|
250
|
Size A in inches, see drawing Below
|
5 7/16
|
5 5/8
|
5 5/8
|
5 41/64
|
6 1/8
|
8 1/8
|
8 1/4
|
8 3/4
|
9 23/32
|
9 23/32
|
Size B in inches, see drawing Below
|
11 11/16
|
14 3/8
|
14 27/32
|
15 5/8
|
17 1/8
|
17 7/16
|
19 11/16
|
21 3/4
|
24 11/16
|
24 11/16
|
Size C in inches, see drawing Below
|
2 7/8
|
3 7/64
|
3 7/64
|
3 1/32
|
3 1/32
|
3 1/32
|
4 1/4
|
4 1/4
|
5 23/64
|
5 23/64
|
Size D min./max. in inches, see drawing Below
|
8 21/32 / 17 21/64
|
9 27/32 / 19 11/16
|
11 13/16 / 23 5/8
|
14 9/16 / 29 9/64
|
14 9/16 / 29 1/8
|
14 3/4 / 29 1/8
|
19 11/16 / 39 3/8
|
19 11/16 / 39 3/8
|
23 5/8 / 47 1/4
|
23 5/8 / 47 1/4
|
Size E in inches, see drawing Below
|
5 55/64
|
6 19/64
|
6 19/64
|
6 19/64
|
7 7/8
|
7 7/8
|
7 7/8
|
9 7/16
|
10 5/32
|
10 5/32
|
Size F, diameter in inches, see drawing Below
|
4 13/32
|
5 1/8
|
5 1/8
|
5 1/8
|
5 5/16
|
5 7/8
|
5 7/8
|
7 5/16
|
8 11/32
|
8 11/32
|
Size G min. in inches, see drawing Below
|
4 21/64
|
4 59/64
|
5 29/32
|
7 9/32
|
7 5/16
|
7 5/16
|
9 13/16
|
9 13/16
|
11 13/16
|
11 13/16
|
Size H, diameter in inches, see drawing Below
|
4 21/64
|
4 59/64
|
5 29/32
|
7 9/32
|
7 5/16
|
7 5/16
|
9 13/16
|
9 13/16
|
11 13/16
|
11 13/16
|
Installation and user manual BOW Thruster 185 mm BOW9512D, BOW9524D
Drill Pattern Thruster Tunnel 185 mm diam
Maintenance and Warranty Manual for thrusters