One complete solution to protect rudders and running gear

Last month we gave a summary of the most important Ecospeed projects of 2018. This month we will be focusing on Ecoshield. In the past year numerous rudders, thruster tunnels and nozzles were coated with our protective coating system designed specifically to give lasting protection against cavitation and corrosion damage.


In 2018 applications were carried out in shipyards in Turkey, the Netherlands, Singapore, Hong Kong, China, Japan, Denmark, Estonia, Germany and the United States and this on a wide range of ships. These included vehicle carriers, ferries, tankers, yachts, research vessels and container ships. The rudders as well as the running gear of these ships will be protected against cavitation and corrosion damage for the rest of their service lives.

Well over thirty vessels belonging to fourteen different owners were treated. Some of them were new customers, some returning ones. They had experienced firsthand the devastating effect of cavitation when a traditional coating system is used. For this reason they decided to use Ecoshield to ensure lasting protection against corrosion and erosion damage for the rudders, nozzle rings and tunnel thrusters of their vessels.

Ecoshield has been designed to give a very thorough and lasting protection against cavitation and corrosion. If the cavitation cannot pierce the coating then no other damage can occur.

Tests conducted in a flow channel have confirmed that Ecoshield performs extremely well under severe cavitation. These tests were divided into six stages during which the coating was exposed to an increasing pressure drop, creating a growing cavitation force. Even after the last stage no erosion was present on the patch coated with Ecospeed.

Suited for newbuilds and existing vessels


As a consequence of cavitation and corrosion damage on their rudders many ships are given a condition of class. Such a condition of class can have a great impact on the vessel’s sailing schedule if for instance it is not allowed to enter certain ports or needs to go to drydock before a certain period of time has passed.

Understandably the owner then wants to try to hold off going to drydock as long as possible and ideally until the five year interval has passed. Temporary repairs are carried out after which the class requires that a new inspection is performed every three months.

When such a vessel eventually comes into drydock, maintenance work on the vessel’s stern area, especially cavitation damage repair, can take a long time. Most of these repairs cannot be performed concurrently. This is the result of the close proximity of the rudder, the propeller and the stern area, along with the strict procedures concerning blasting, painting and welding work. Painting is therefore usually assigned to the end of the schedule and as a consequence may not get done at all or else prolongs the stay in drydock. Taking into account the tight drydock schedule of most vessels this is often very problematic.

With an Ecoshield application one can avoid these problems from day one because no repaint of the running gear will be needed during drydocking. Ecoshield will remain intact for the lifetime of the vessel and is guaranteed for ten years. At the most, touch-ups amounting to less than 1% of the surface area will be required. Planning the maintenance of the vessel’s stern area therefore becomes much easier.

The newbuild phase is the perfect time to apply Ecoshield. However, the coating can also be used to protect vessels that have been in service for some time and are already facing cavitation and corrosion damage.

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. This means that for smaller surfaces such as rudders or bow thrusters the two required coats can usually be applied in one single day.

Conclusion


If one takes into account the costs of the temporary underwater repairs and the regular inspections required by a condition of class or the costs for rudder repairs in drydock, it becomes clear that the investment in a coating system that offers extra protection is won back from day one. More and more owners have Ecoshield applied on the rudders and running gear of a large part of their fleet or have it included in the rudder specs of their newbuild vessels. These owners invest in the right coating system for the savings that will result.

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

Belgian headquarters
Phone: +32 3 213 5318
Fax: +32 3 213 5321
info@subind.net

US Office
Phone: +1 727 443 3900
Fax: +1 727 443 3990
info.us@subind.net

Related product(s):

Ecoshield

Durable protection against cavitation damage for running gear

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