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Home > Anchor & Docking > Bow & Stern Thruster > Vetus Bow & Stern Thruster >

Vetus Hydraulic Thruster




A bow thruster delivers a side directional thrust force. In order to ensure the best performance under all sorts of weather and water conditions, the bow thruster should be able to provide a thrust force which is suitable, or rather: sufficient, for the boat in which it has been installed. The applied moment of the thrust force - which means to say: the position of the tunnel in the bow - is of prime importance for the bow thruster's efficiency. The further forward the bow thruster is positioned, the greater will be the efficiency.





Vetus Hydraulic Bow Thruster 121 Lb Including Hydro Motor 3.5Kw, 4HP, BOW55HMD
Vetus Hydraulic Bow Thruster 1215 Lb Including Hydro Motor, 33Kw (44 HP), BOW550HMD (Truck Freight)
Vetus Hydraulic Bow Thruster 121 Lb Including Hydro Motor 3.5Kw, 4HP, BOW55HMD

Brand New with Factory Warranty

List Price: $US 2,156.25
Our Price: $US 2,156.25

Click "Add to Cart" Button To See Our Price! Why?
Vetus Hydraulic Bow Thruster 1215 Lb Including Hydro Motor, 33Kw (44 HP), BOW550HMD (Truck Freight)

Brand New with Factory Warranty

List Price: $US 9,000.00
Our Price: $US 9,000.00

Click "Add to Cart" Button To See Our Price! Why?
Vetus Hydraulic Bow Thruster 200 Lb Including Hydro Motor 6.0Kw, 8HP, BOW95HMD
Vetus Hydraulic Bow Thruster 352 Lb Including Hydro Motor 9.5Kw, BOW160HMD
Vetus Hydraulic Bow Thruster 200 Lb Including Hydro Motor 6.0Kw, 8HP, BOW95HMD

Brand New with Factory Warranty

List Price: $US 2,381.25
Our Price: $US 2,381.25

Click "Add to Cart" Button To See Our Price! Why?
Vetus Hydraulic Bow Thruster 352 Lb Including Hydro Motor 9.5Kw, BOW160HMD

Brand New with Factory Warranty

List Price: $US 2,906.25
Our Price: $US 2,906.25

Click "Add to Cart" Button To See Our Price! Why?
Vetus Hydraulic Bow Thruster 507 Lb Including Hydro Motor 12Kw, BOW230HMD
Vetus Hydraulic Bow Thruster 662 Lb Including Hydro Motor 20 KW, 27HP, BOW310HMD
Vetus Hydraulic Bow Thruster 507 Lb Including Hydro Motor 12Kw, BOW230HMD

Brand New with Factory Warranty

List Price: $US 4,074.00
Our Price: $US 4,074.00

Click "Add to Cart" Button To See Our Price! Why?
Vetus Hydraulic Bow Thruster 662 Lb Including Hydro Motor 20 KW, 27HP, BOW310HMD

Brand New with Factory Warranty

List Price: $US 4,376.25
Our Price: $US 4,376.25

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Vetus Hydraulic Bow Thruster 905 Lb Including Hydro Motor 22Kw, 29HP, BOW410HM (Truck Freight)
Vetus Hydraulic Pump with 1.83 cubic inch with Cast Iron Body, Left Handed HT1016SD1
Vetus Hydraulic Bow Thruster 905 Lb Including Hydro Motor 22Kw, 29HP, BOW410HM (Truck Freight)

Brand New with Factory Warranty

List Price: $US 8,250.00
Our Price: $US 8,250.00

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Vetus Hydraulic Pump with 1.83 cubic inch with Cast Iron Body, Left Handed HT1016SD1

Brand New with Factory Warranty

List Price: $US 3,402.00
Our Price: $US 2,299.00

Vetus Hydraulic Pump with 1.83 cubic inch with Cast Iron Body, Right Handed HT1017SD1
Vetus Hydraulic Pump with 2.75 cubic inch with Cast Iron Body HT1015SD2
Vetus Hydraulic Pump with 1.83 cubic inch with Cast Iron Body, Right Handed HT1017SD1

Brand New with Factory Warranty

List Price: $US 3,402.00
Our Price: $US 2,299.00

Vetus Hydraulic Pump with 2.75 cubic inch with Cast Iron Body HT1015SD2

Brand New with Factory Warranty

List Price: $US 3,596.00
Our Price: $US 2,399.00

Vetus Hydraulic Pump with 2.75 cubic inch with Cast Iron Body, Left Handed HT1016SD2
Vetus Hydraulic Pump with 2.75 cubic inch with Cast Iron Body, Right Handed HT1017SD2
Vetus Hydraulic Pump with 2.75 cubic inch with Cast Iron Body, Left Handed HT1016SD2

Brand New with Factory Warranty

List Price: $US 3,596.00
Our Price: $US 2,399.00

Vetus Hydraulic Pump with 2.75 cubic inch with Cast Iron Body, Right Handed HT1017SD2

Brand New with Factory Warranty

List Price: $US 3,596.00
Our Price: $US 2,399.00

Vetus Hydraulic Pump with 4.57 cubic inch with Cast Iron Body, Left Handed HT1022SD
Vetus Hydraulic Pump with Aluminum Body, 2.75 in3, Side Connection, Left Handed HT1016
Vetus Hydraulic Pump with 4.57 cubic inch with Cast Iron Body, Left Handed HT1022SD

Brand New with Factory Warranty

List Price: $US 5,628.00
Our Price: $US 3,699.00

Vetus Hydraulic Pump with Aluminum Body, 2.75 in3, Side Connection, Left Handed HT1016

Brand New with Factory Warranty

List Price: $US 2,999.00
Our Price: $US 2,399.00

Vetus Dual step load sensing device, incl. electrical connection box HT1012
Vetus Dual step solenoid control unit 24 V, for anchor windlass HT102312
Vetus Dual step load sensing device, incl. electrical connection box HT1012

Brand New with Factory Warranty

List Price: $US 1,798.00
Our Price: $US 1,299.00

Vetus Dual step solenoid control unit 24 V, for anchor windlass HT102312

Brand New with Factory Warranty

List Price: $US 573.75
Our Price: $US 489.00

Vetus Hydraulic Tank 18.5 Gallon (70 Liters) (Excluding Control Device) HT1010
Vetus Hydraulic Tank 34.3 Gallon (130 Liters) (Excluding Control Device) HT1010BS
Vetus Hydraulic Tank 18.5 Gallon (70 Liters) (Excluding Control Device) HT1010

Brand New with Factory Warranty

List Price: $US 3,888.00
Our Price: $US 2,549.00

Vetus Hydraulic Tank 34.3 Gallon (130 Liters) (Excluding Control Device) HT1010BS

Brand New with Factory Warranty

List Price: $US 5,999.00
Our Price: $US 4,399.00

Vetus Manifold for additional control units HT1026
Vetus Single step load sensing device, incl. electrical connection box HT1011
Vetus Manifold for additional control units HT1026

Brand New with Factory Warranty

List Price: $US 1,390.00
Our Price: $US 1,299.00

Vetus Single step load sensing device, incl. electrical connection box HT1011

Brand New with Factory Warranty

List Price: $US 826.00
Our Price: $US 689.00

Vetus Single step solenoid control unit 24 V, for anchor windlass HT102311
Vetus Solenoid control unit 24 V, for bow & stern thrusters HT1013
Vetus Single step solenoid control unit 24 V, for anchor windlass HT102311

Brand New with Factory Warranty

List Price: $US 884.50
Our Price: $US 729.00

Vetus Solenoid control unit 24 V, for bow & stern thrusters HT1013

Brand New with Factory Warranty

List Price: $US 301.50
Our Price: $US 289.00

Vetus Solenoid control unit 24 V, for lowering mast or radar support HT1014
Vetus Solenoid control unit 24 V, for power steering system or autopilot HT1019
Vetus Solenoid control unit 24 V, for lowering mast or radar support HT1014

Brand New with Factory Warranty

List Price: $US 1,507.00
Our Price: $US 1,339.00

Vetus Solenoid control unit 24 V, for power steering system or autopilot HT1019

Brand New with Factory Warranty

List Price: $US 2,246.00
Our Price: $US 1,959.00

Vetus Solenoid control unit 24 V, for use with a set of stabilizers HT1024
Vetus Solenoid control unit 24 V, for use with a set of stabilizers HT1024

Brand New with Factory Warranty

List Price: $US 1,040.00
Our Price: $US 969.00


Selecting the correct Bow Thruster

A bow thruster delivers a side directional thrust force. In order to ensure the best performance under all sorts of weather and water conditions, the bow thruster should be able to provide a thrust force which is suitable, or rather: sufficient, for the boat in which it has been installed. The applied moment of the thrust force - which means to say: the position of the tunnel in the bow - is of prime importance for the bow thruster's efficiency. The further forward the bow thruster is positioned, the greater will be the efficiency.

 
The force applied by the wind onto the boat is determined by the factors: wind speed, angle of wind attack and lateral wind draft area of the boat.
  • The Wind Pressure
    When the wind speed increases, the wind pressure increases quadraticallly!
    For wind pressure 'P', the formula reads: P = 1/2p V (l bf/sq.ft)
    p (rho) represents the specific mass of air and 'V' stands for the
    velocity of the air in ft/s.
    The table below will give you an impression of wind speeds and the resulting wind pressures. It will not be possible to counter completely the adverse effect of winds of 40 knots or more. But, in such cases, the bow thruster will still "lend a strong helping hand".
     
  • The Wind-Draft of the Boat
     The forces applied by the wind onto the boat can be determined by multiplying the wind pressure by the wind draft area. The wind draft area is determined by the shape and the dimensions of the superstructure. Also the wind angle is playing its part. The worst situation is created if the wind is at 90 degrees to the boat. However, due to the shape of the superstructure, which is mostly more or less streamlined, a reduction factor may be applied to the wind draft area, before calculating the wind pressure resulting from the wind speed. This reduction factor may generally be set at 0.75.
     
  • The Torque
    The torque is determined by multiplying the wind force by the distance (A) between the center of effort* of the wind and the center of rotation** of the boat. Assuming that the wind force is amidships and assuming as well that the boat will tend to turn at the transom, the torque, caused by the wind force, is calculated by multiplying the wind force by half of the boat's length.
     
    * - Dependent upon the shape of the boat's superstructure, the center of effort may be positioned more forward or more aft.
    ** - The center of rotation of the boat may be positioned more forward, dependent upon the shape of the underwater section.
     
  • The Thrust Force
     The bow thruster is required to apply a countering thrust force, which is at least equal to the thrust force applied by the wind. The required thrust force of the bow thruster may now be calculated by dividing the torque by the distance between the center of the bow thruster and the pivot point of the boat.

Wind Speed - Wind Pressure Chart

Wind Speed
knots
Description Wind Speed
ft/s
Wind pressure lbf/sq.ft.
10 - 16
16 - 22
22 - 28
28 - 34
34 - 40
moderate breeze
fresh breeze
strong breeze
near breeze
gale
17 - 27
27 - 37
37 - 47
47 - 57
57 - 67
0.40 - 1
1 - 1.9
1.9 - 3.1
3.1 - 4.6
4.6 - 6.3

Calculation example

The boat has an overall length of 36 ft and the lateral wind draft measures 190 sq.ft. It is required that the bow can still be controlled easily when a wind force of 20 knots applies. At a wind force of 20 knots, the wind pressure is:

p = 1.0 to 1.9 lbf/sq.ft i.e.p. (average) 1.45 lbf/sq.ft.

The required torque reads:

T = windpressure x wind draft x reduction factor x distance center of effort to pivot point, (=appr. half the ship's length)

T = 1.45 lbf/sq.ft x 190 sq/ft x 0,75 x 36 ft/2 = 3719 ft.lbs.

The required Thrust Force is calculated as follows:

F = Torque/distance between the center of bow thruster and the pivot of the boat

= 3719 ft/lb / 34.5 ft = 107.8 lb

The VETUS bow thruster which is most suitable for this particular vessel is the 121 lbf model.

Always bear in mind that the effective performance of a bow thruster will vary with each particular boat, as the displacement, the shape of the underwater section and the positioning of the bow thruster will always be variable factor.

 
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