Rudders, kort nozzles, thruster tunnels and other running gear of a ship are particularly susceptible to the devastating damage that can be caused by cavitation and corrosion. This can result in deep pitting and sometimes complete failure, needing very expensive repairs or replacement. The problem has remained unsolved until now.

When a ship comes into drydock, maintenance of its rudder and running gear can be expensive and time-consuming. Cavitation and corrosion damage repair often involves hot work, grinding and recoating. Thus a poorly protected and damaged rudder or other running gear can extend drydocking time and costs considerably. 

The costs involved go far beyond simply repairing and recoating the damaged rudder. Drydock expenses and off-hire time add up quickly. And if underwater repairs are needed for these parts in between drydocking, further expense is incurred.

The effects of cavitation damage on rudders, thruster tunnels and other running gear can be devastating

(Left, above) A rudder that has been repaired with welding after severe cavitation damage and corrosion. (Right) A thruster tunnel showing corrosion and cavitation damage. 

ECOSHIELD breakthrough

However, a recent breakthrough has changed all of this: ECOSHIELD.

Ecoshield is glass-platelet reinforced protection for rudders, kort nozzles, thruster tunnels, bulbous bows, azimuth thrusters, stabilizer fins and other parts of the ship, whether steel, aluminum or GRP. It lasts the service life of the vessel without need for recoating or major repair – at most, quick and easy touch-ups amounting to less than 1% of the surface area will be required during routine drydocking. Ecoshield comes with an unheard-of ten-year guarantee. 

Planning the maintenance of the vessel’s stern area therefore becomes much easier.

Ecoshield is a reinforced version of the well-known Ecospeed non-toxic underwater ship hull coating. Small but significant variations of the Ecospeed formula have been tested on rudders since 2002 with extraordinary results. Ships that were experiencing heavy cavitation damage to their rudders, once the glass-flake coating was applied, have seen no further cavitation damage erosion for as long as 15 years after application, with no sign that the coating will need replacement during the life of the ship.

Below you see a rudder 10 years after it was originally coated with Ecoshield, with no repainting over that entire time, only minor touch-ups. 

A rudder coated with Ecoshield after 10 years with no repainting is still in excellent condition.

(Above) Rudder in excellent condition 10 years after Ecoshield was applied, with no repainting over that period. 

Extremely cost-effective permanent protection

The perfect time to apply Ecoshield is at newbuild. However, the coating can also be used to protect vessels that have been in service for some time using traditional coatings and are already facing cavitation and corrosion damage. There is even a filler of the same composition, Ecofix, which can be used to repair pitting and corrosion damage and restore the surface prior to the application of Ecoshield. 

Ecoshield’s flexibility makes it easy to adapt the application schedule to the rest of the activities at the shipyard or drydock in a way which does not interfere with them. Overcoating time can be as short as three hours, which means that for smaller surfaces, such as rudders or bow thrusters, the two coats required can usually be applied in one single day. Even if three or four coats are being applied, the time is short compared to other coating systems, which are far less effective. 

The costs of the temporary underwater repairs and the regular inspections required by a condition of class until the next drydocking can be high. So can the costs for rudder repairs in drydock. Thus, it becomes clear that the investment in a coating system that offers extra protection from day one is very easily won back. For this reason more and more owners have Ecoshield applied on the rudders and other running gear of a large part of their fleet or have it included in the rudder, nozzle, etc. specs of their newbuild vessels. These owners invest in the right coating system for protection because they know the savings that will result.

Download the Ecoshield brochure for more details:

Ecoshield Digital Brochure

A White Paper with full details about protecting rudders and running gear from cavitation damage is available for free download in the Downloads section below.


White Paper 6 Rudder Cavitation Damage Solved

You can give the rudders and running gear of your vessels the same lifelong protection. Contact us for more information.

Ecoshield is the ultimate solution for protecting a ship's rudder and running gear from the forces of cavitation. 

E-mail us for more information, a consultation or a quote: info@subind.net

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