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Large Thruster Tunnel Corrosion Protection
Bow and stern thruster protection is a specialized area
where Corrintec have developed at system which is uniquely
effective in providing corrosion protection.
Problems of corrosion arise because of the dissimilarity
of the materials used in the hull and thruster tunnel construction
and remain unchecked because they are outside the scope of
conventional ICCP systems.
Corrintec’s thruster tunnel systems are installed
on ocean going vessels, harbour tugs and in offshore oil
and gas applications.
The equipment consists of a power unit/controller and an
arrangement of reference cells and anodes positioned on either
side of the tunnel. The anodes and reference electrodes are
flush mounted to maintain the optimum performance of the
thrusters and reduce the effects of turbulence which can
accelerate corrosion.
This has a number of advantages in comparison with sacrificial
anode systems where anodes are much heavier, have to be checked
at regular intervals and replaced at each drydocking. In
contrast, the Corrintec system provides carefully monitored
and precisely delivered corrosion protection for a design
life up to 15 years.
The system operates continuously when the vessel is at sea,
but when the impellor is activated during manouvering, the
equipment is automatically shut down using a fail-safe switching
system
which is installed by shipyard. This prevents any stray current
damage occurring to the bearings and seals.
In cases where ships are fitted with sacrificial systems,
Corrintec monitoring equipment can be used to check the performance
of the anodes. The system consists of a small control panel
with the option of a digital or analogue display. This is
connected to an arrangement of reference cells which measure
the electrical potential flush mounted to avoid the risk
of ‘drag’ and turbulence. The system enables
ship’s engineers to regularly monitor the status of
cathodic protection as well as indicating when anode renewal
is necessary. |
