VETUS GRP Stern-Thruster Installation Guide

1 Introduction

VETUS GRP thrust tunnels can be installed as stern thrusters. The electric motor is housed inside the vessel, providing reliable protection and easy serviceability. Using this thrust tunnel offers:

• Shielded propeller, significantly reducing the risk of damage or injury.
• Optimized water flow for high thrust output.

This guide covers installation aspects specific to using the thrust tunnel as a stern thruster. For the complete installation of the stern thruster, consult the relevant VETUS bow thruster instruction manual.

2 Operation

For stern thruster operation, refer to the owner's manual of the installed bow thruster.

Note: Never use the stern thruster as a boarding step. Stepping on the thrust tunnel can damage the propeller and the tunnel, potentially affecting operation and causing leaks at the hull seal.

3 Maintenance

The GRP thrust tunnel requires no maintenance.

4 Installation

For overall dimensions, consult the drill pattern.

4.1 General

The reliability of the stern thruster is highly dependent on the quality of the installation. Most problems arise from installation faults or inaccuracies. It is crucial to follow and check all points in this manual.

If the available height at the stern is insufficient, a sloped surface can be created for installation. Ensure the thrust tunnel is protected against water flow forces during normal cruising.

Installation in the bottom of the vessel is not recommended, as the thrust tunnel is not designed to withstand normal cruising water flow forces, and it can significantly slow down normal propulsion.

4.2 Positioning of the stern thruster

When selecting the location, ensure the centerline of the thrust tunnel is at least 'X' mm below the waterline for optimal results. Consult the drill pattern for the value of 'X'.

The electric motor must be positioned clear of the maximum bilge water level.

Consult the drill pattern for the maximum allowable hull thickness.

Diagram Description: An illustration shows the stern thruster positioned relative to the waterline, with a requirement for the centerline to be below a certain level ('X'). Another diagram indicates the electric motor should be clear of the bilge water level. A third diagram shows a requirement for maximum hull thickness.

The stern must be level. If not, it must be filled out with a spacer. The total thickness of the spacer must be less than or equal to the maximum allowable thickness of the stern.

Diagram Description: An illustration shows the stern thruster requiring a level mounting surface. If the hull is not level, a spacer should be used, ensuring the total thickness does not exceed the maximum allowable hull thickness.

4.3 Installation of the flange

At the installation location, attach the drill pattern to the outside of the hull and mark the holes.

Note: The centerline of the drill pattern must be precisely horizontal and at least 'X' mm below the waterline.

Diagram Description: An illustration shows a drill pattern being aligned on the hull, with markings for drilling holes. A note emphasizes the horizontal alignment and depth below the waterline.

For checking purposes, drill a small pilot hole at the center point of the flange location. This allows for easy checking of the available space for the flange and motor from the inside.

Diagram Description: An illustration shows a pilot hole being drilled at the center point of the planned flange installation. This is followed by an interior view showing space check for the flange and motor.

Apply a sealant (e.g., polyurethane sealant like Sikaflex 292) to the mounting surface of the thrust tunnel and position it onto the hull.

Diagram Description: An illustration shows sealant being applied to the mounting surface of the thrust tunnel before it is attached to the hull.

Install the thrust tunnel using bolts, nuts, and washers. These are not supplied and must be ordered separately. Consult the drill pattern for bolt length, which depends on the hull thickness.

Diagram Description: An illustration shows the thrust tunnel being secured with bolts, nuts, and washers. It notes that these parts are separate and bolt length depends on hull thickness.

Drill the holes according to the hull material, using a drill, jigsaw, or oxy-acetylene cutter. Ensure the holes are free of burrs.

Diagram Description: An illustration shows the process of making holes in the hull, with options for drilling, jigsaw, or cutting. It emphasizes removing burrs from the holes.

4.4 Installation of the 'bow thruster'

The bow thruster must be installed according to its relevant instruction manual.

Check that the distance between the propeller blade tips and the inside of the thrust tunnel is consistent all around the periphery.

Diagram Description: An illustration shows the bow thruster propeller inside the tunnel, with an arrow indicating the need to check the clearance between the propeller tips and the tunnel wall, ensuring it is uniform.