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 150 mm BOW3512E
Drill Pattern Thruster Tunnel 150 mm diam
Maintenance and Warranty Manual for thrusters