4
GB
3.2 Preparing the hole for the tube
TT Thruster can be fitted new or as a replacement for
an existing thruster. Tunnel dimensions listed on the
following table.
NOTE: Check mounting holes on the saw template
‣ The recommended tunnel is designed to fit a
Lewmar saddle, take the weight of the Thruster
and the torque of the motor.
‣ Fig 3.1.3 - To reduce any potential loss of
performance or damage to the propeller the
entrance of the tunnel can be altered to improve
thrust as well as reduce noise.
Fig 3.1.3
Fig 3.2.1
Fig 3.2.3
Fig 3.2.2
When you are satisfied the best location for the
Thruster unit has been found within the parameters
available proceed as follows.
‣ Fig 3.2.1 - Make a jig to precisly align the drill holes
either side of the hull.
NOTE: Double check everything before drilling.
‣ Drill a pilot hole in both sides of the hull.
‣ Form a wire guide to diameter of the tunnel hole,
mark, check and cut.
‣ Insert tube in the hole, mark and remove excess.
‣ Grind off gel coat etc. Insert tunnel and fix allowing
enough room inside for saddle location on the
tunnel.
‣ Gel coat finished installation and antifoul.
THRUSTER MODEL
(kW)
INSIDE DIAMETER
WALL THICKNESS
mm
inch
mm
inch
110 (1.5)
110
4
5
/
16
5.0
3
/
16
140 (2.0)
140
5 1/2
4.0-5.0
5
/
32
-
3
/
16
⚠ For general guidance for GRP boats only.
Problems caused by faulty installation of the
tunnel are the installers full responsibility.
⚠ A competent, marine engineer must carry
out any work on the hull of your boat.
r = 0.1 Ø
