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Installing and Operating Vetus 410 and 550 Hydraulic Bow Thrusters


Installation instructions
Installation recommendations
Hydraulic installation
Electrical installation
Trouble shooting
Technical data
Installation examples
Hydraulic diagrams
Principal dimensions


The thrust given by the bow thruster will vary from vessel to vessel depending on the effect of the wind, the water displacement and the shape of the underwater hull.

The nominal thrust quoted can only be achieved under the most favourable conditions. Therefore, the following factors are to be observed:

  • low and pressure of the pump must be attuned to the hydraulic motor.
  • The actual method of connecting the thrust tunnel to the ship's hull is of utmost importance for the best possible performance. See paragraph 'installation instructions'.
  • Only when absolutely necessary (e.g. when sailing frequently in muddy or polluted waters) grids may be installed to the tunnel openings.
  • In case such grid bars are being fitted, please observe closely the recommendations made in paragraph 'installation instructions'.
  • Compliance with the recommendations that follow hereafter, will result in a longer life and better performance of the bow thruster:

  • Never run the bow thruster continuously for a long period of time. With a view to the internally generated heat.
  • Check during sailing that the maximum temperature of the hydraulic oil doesn't exceed a temperature of 100 degrees C.
  • All of the specified maintenance should be carried out regularly.
  • Safety


    When using the bow thruster watch out for swimmers or light boats which could be in the near vicinity of the bow thruster tunnel jet openings.

    Pass on the safety instructions to others using the bow thruster.

    General rules and laws with regard to safety and accident-prevention also need to be applied.

  • Never touch the moving ends of the bow thruster whilst in operation.
  • Never touch hot parts of the bow thruster and never place flammable materials in the vicinity of the bow thruster.
  • Always stop the bow thruster before checking components or adjusting the bow thruster.
  • Ensure maintenance work is safe by only using tools suitable for the purpose.
  • Always deactivate the main switch when the bow thruster is not in use for long periods.
  • Use


  • The bow thruster can only be used if the main engine, which drives the hydraulic pump, is in operation.
  • The thrust of the bow thruster depends on:

         -the number of revolutions of the main motor

         -the number of pieces of hydraulic equipment switched on (for instance simultaneous use of both bow thruster and stern thruster)

  • Depending on the type of load-sensing-valve used, the bow thruster must be operated using the appropriate control panel:

         -1-step load-sensing-valve:
    3-position lever switch: BPJ or BPJE, or selector switch: BPS or BPSE

         -2-step load-sensing-valve:
    5-position lever switch: BPJH5 or BPJSTH5


    If 2 control panels are installed never operate
    the bowthruster from both panels simultaneously.

    3-position lever switch, or selector switch

    - Switch the main switch on.
    - Switch the panel on.

    - The valve is operated by means of the lever switch.

    -The lever will not stay in positions 'L' and 'R'. The lever will always jump back to the middle position 'C'.
    - After using the bow thruster switch the panel off.
    - Switch the main switch off when leaving the ship.
    5-position lever switch

    - Switch the main switch on.
    - Switch the panel on.

    - The valve is operated by means of the lever switch.

    -In positions '1L' and '1R' the bow thruster works at approximately half the thrust (depending on the load-sensing pressure set).
    In positions '2L' and '2R' the bow thruster works at full thrust.
    The lever will not stay in positions '2L' and '2R'. The lever will always jump back to position '1L' or '1R'.
    - After using the bow thruster switch the panel off.
    - Switch the main switch off when leaving the ship.

    Installation instructions

    These installation instructions give guidelines for fitting the Vetus bow thrusters 'BOW410HM' and 'BOW550HM'.

    The standard of fitting determines the reliability of the bow thruster. Almost all faults experienced can be traced back to mistakes or inaccuracies during fitting. It is therefore of the utmost importance to follow the installation instructions meticulously during fitting and to check these carefully.

    Make sure that the user of the vessel is supplied with the owner's manual.

    Installation recommendations

    The room where the hydraulic motor of the bow thruster is installed should be dry and well ventilated.

    Positioning of thrust tunnel

    To achieve the optimum performance, position the thrust tunnel as far forward as possible.

    If, in addition to controlling the movement of the bow, the stern of the vessel is required to move sideways, then a second thruster may be installed at the stern.

    If the vessel planes the tunnel should, if possible, be so situated that when the vessel is planing it is above the water level thus causing no resistance.
    Installation of two bow thrusters in tandem (for larger boats). In this case, depending on weather conditions, one or both bow thrusters may be used.

    Connection of thrust tunnel to ship's hull

    The manner, in which the thrust tunnel is connected to the ship's hull, is of great influence to the actual performance of the bow thruster and to the drag that the hull produces when under way.

    Direct connection of the tunnel to the hull, without a fairing, produces reasonable results.

  • A The connection to the hull can be abrupt.
  • B It is better to make the connection rounded with radius 'R' of about 0.1 x D.
  • C It is even better to use sloping sides 'C' with dimensions 0.1 to 0.15 x D.
  • Connection of the thrust tunnel to the ship's hull with a fairing results in lower hull-resistance during normal sailing.

  • A The connection with a fairing can be abrupt.
  • B It is better to make the connection with a fairing rounded with radius 'R' of about 0.1 x D.
  • C The best connection is with a fairing using sloping side 'C' with dimensions 0.1 to 0.15 x D.

  • Length 'L' of the fairing should be between 1 x D and 3 x D. This fairing should be embodied in the ship's hull in such a way that the centerline of the fairing will correspond with the anticipated shape of the bow-wave.
    If the connection of the thrust tunnel and the ship's hull is to be made with a sloped side, it should be executed in accordance with the drawing. Make the sloped side (C) with a length of 0.1 to 0.15 x D and make sure that the angle between the tunnel and the sloped side will be identical to the angle between the sloped side and the ship's hull.

    Grid bars in the tunnel openings

    Although the thrust force will be adversely affected, grid bars may be placed into the tunnel openings, for protection of the thruster.

    In order to minimize as far possible the ill effects to the thrust power and the hull's resistance whilst under way, make sure that:

  • no more than 4 grid bars per opening will be fitted
  • the bars should have a rectangular section, as shown in the drawing, as well as a certain overlap ( see figure 3 above ).
  • the bars should be positioned perpendicularly to the shape of the bow wave to be expected.
  • Protection of the bow thruster against corrosion To prevent corrosion problems, do not use copper based anti-fouling. Cathodic protection is a 'must' for the protection of all metal parts under water.
    In order to protect the bow thruster tailpiece against corrosion, the tailpiece is supplied with a zinc anode.
    Corrosion of a steel or aluminium thrust tunnel can be reduced by ensuring that the tail piece is completely insulated from the thrust tunnel. NOTE: The gaskets supplied are already electrically insulated. However the bolts and the shaft need to be fitted with insulation material, for example nylon bushes. ( see figure 4 below ).


    Installation of the thrust tunnel

    Drill 2 holes into the ship's hull, where the centerline of the thrust tunnel will be, in accordance with the diameter of the marking tool.
    Pass the marking tool (home-made) through both pre-drilled holes and set out the outside diameter of the thrust-tunnel to the hull.>/td>
    Dependent on the vessel's construction material, cut out the holes by means of a jigsaw or an oxy-acetylene cutter.
    Install the thrust-tunnel.

    Polyester thrust tunnel:
    Resin: The resin used for the polyester thrust tunnel is Isophtalic polyester resin (Norpol Pl 2857).
    Pre-treatment: The outside of the tunnel must be roughened.
    Remove all of the top surface down to the glass-fibre. Use a grinding disc for this.
    Important: Treat the end of the tunnel, after it has been sawn to length, treat the end of the tube with resin. This will prevent water seeping in.
    Laminating: Apply a coat of resin as the first coat. Lay on a glass-fibre mat and impregnate with resin. Repeat this procedure until you have built up a sufficient number of layers.
    A polyester thrust tunnel should be finished as follows:
    Roughen the hardened resin/glass-fibre. Apply a top coat of resin. Treat the side of the tunnel which comes into contact with water with 'epoxy paint' or 2-component polyurethane paint.
    Then apply anti-fouling treatment if required.

    Drilling the holes in the thrust-tunnel

    Use the drill pattern supplied, to determine the correct position of the holes to be drilled.
    Important: The pattern of the holes must be positioned precisely on the centerline of the tunnel.
    Drill the holes through the thrust tunnel and take care that the holes are free of burrs.

    Installation of tail piece

    Remove the propeller.

    Install the gasket between the tail piece and the thrust tunnel.
    Apply a sealant (polyurethane* or silicon), and position the tail piece into the hole in the thrust tunnel.

    Mount the adapter flange on the tail piece. Grease the threads of the bolts with 'outboard gear grease' before before mounting them.

    *) e.g. Sikaflex-292.

    Check for possible leaks immediately the ship returns to water.

    Final assembly

    Make sure that the key (1) is properly positioned in the keyway of the shaft.
    Grease the shaft with 'outboard gear grease' and install the propeller (2) with the O-ring (3) and the hexagonal nut (4).
    Secure the nut with the lock-screw (5). Fit the zinc anode (6) to the propeller shaft by means of the bolt (7).

    The propeller should be at least 1.5 mm free of the thrust tube wall, all round.

    Fit the connections in the tail piece.

    Trouble shooting

    Hydraulic motor rotates (too) slowly.
    - Speed of the hydraulic pump is (too) low.

    Hydraulic motor does not rotate at all.
    - Check whether the main switch is in position 'ON'.
    - Check whether the control circuit fuse is blown. Control circuit is shortened, check wiring. - Transmission of the hydraulic pump is faulty.

    The hydraulic system looses oil.
    - Check all tubing and connections for possible leakage.


    Check the cathodic protection and if necessary renew the zinc anode.
    There is a spare part set, including a zinc anode, available. Art. code: SET0075.

    Clean the propeller shaft, grease with 'outboard gear grease and refit the propeller on the shaft.

    Hydraulic motor

    The hydraulic motor requires no specific maintenance

    Technical Data

    Type : BOW410HM BOW550HM
    Hydraulic motor
    Type : Reversible motor Reversible motor
    Rated output : 22 kW 33 kW
    Flow rate : 92 l/min 92 l/min
    Operating pressure : 180 bar 280 bar
    Capacity : 45 cm3/rev. 45 cm3/rev.
    Tailpiece housing : brass brass
    Diameter : 386 mm (15.2 ") 386 mm (15.2 ")
    No. of blades : 3 3
    Pitch : 11" 13"
    Material : bronze bronze
    Rated thrust : 4100 N (410 kgf, 902 lbf) 5500 N (550 kgf, 1210 lbf)


    Steel model
    dimensions : O.D. 419 mm, wall thickness 11 mm
    treatment : blasted, coated with: 'International' Interplate NFA760/NFA761 primer
    Washprimer, suitable for all kinds of protection systems.

    Plastic model
    dimensions : I.D. 400 mm, wall thickness 12 mm
    material : glass fibre reinforced polyester

    Excl. thrust-tunnel : 40 kg (88 lbs)

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