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Hydrodynamic
design
Refined propeller blades and
conical tunnel inlets provide:
• Minimum
excitation
• Maximum
thrust
Double seals
between inner
and outer tunnel
– in a protected
position, but easy
to inspect
Engineering services
• Selection of thruster
type, size and
location
• Structural
thruster-hull
integration
• Noise
assessments
Resilient mounts
Size, number and location
based on data for:
• Thruster configuration
• Static and dynamic
stiffness
characteristics
for mounts
Acoustic elements
• Specially designed air-filled acoustic
elements between
inner and outer tunnel.
• These elements ensure
that no seals are
required to avoid
acoustic short-
circuiting
between
inner and
outer tunnel.
Structural design
For easy hull integration,
complete full-length double tunnel
suits hull lines and complete
outer tunnel has stiffeners.
Rigid inner and
outer tunnel provides:
• Maximum attenuation
• Rigid support for mounts
• Rigid support for flange-mounted
underwater thruster gearbox
Patented LowNoise thrusters from Brunvoll
Unique full-length
double-tunnel
construction features
an air-water mix
between the outer
and inner tunnel
Acoustic excitation
is fairly constant
along the length
of the tunnel
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