Active cathodic corrosion protection

Cathelco produces electrochemical hull corrosion protection systems with applied current for any type of ship. Installed on more than 6,000 commercial vessels, the C – Shield system combines innovative control panel design with a wide range of hull anodes. Special ferry systems with aluminum and steel hulls and compact systems for small vessels are also available. Regardless of vessel type, Cathelco systems protect them from corrosion with unrivaled efficiency and reliability.

Corrosion Prevention with Coded Current Active Electrochemical Protection Systems

Despite the appearance of modern paints for the case, they do not provide complete protection. Therefore, most ships are equipped with a special system of electrochemical protection of the hull with applied current.

Using anodes and control electrodes mounted on the housing connected to the control panel, the system generates a powerful current and suppresses the natural electrochemical processes on the wetted surface of the housing. This helps to avoid the formation of corrosive elements on the surface and to avoid joint problems or the proximity of dissimilar metals.

The main feature of active cathodic protection systems is that they constantly monitor the electrical potential between the body and the water and accordingly regulate the current flowing through the anodes. This greatly improves efficiency and reliability compared to interchangeable anode systems in which the degree of protection cannot be measured or changed.

Using the C-Shield system, you can reduce the cost of maintaining the housing, as well as save fuel due to the smoothness of its surface. In addition, the increased strength of the case will ensure safety and good technical condition, thereby protecting the owners’ investments.

Modular Control Panels

C-Shield modular cathodic protection control panels based on modern computer electronics are designed for installations with currents up to 450A. They are very light and compact, and can be easily installed in the engine room. The output currents to the anodes can be constantly monitored on a digital display.

One of the main advantages of a modular unit is that its modules are interchangeable and can be quickly removed and replaced if necessary, which increases reliability. The system may include various protection functions, including “above” and “below” protection level alarms. Additional information regarding the status of the system can be transmitted directly to the bridge computer for continuous monitoring of tasks.

  • For active cathodic protection systems with currents up to 450A.
  • Modular design for greater flexibility and reliability.
  • Very light and compact.
  • Clear digital output displays.
  • Built-in protection level alarm.
  • It can be connected to bridge information systems.

Thyristor control panels

These panels combine the time-tested thyristor technology and the latest computer systems. This provides the best value for money for powering even the largest systems of active electrochemical protection.

Thyristor control panels can be used with currents up to 800 Amperes on cruise ships and supertankers, as well as on large container ships and cargo ships. Like modular panels, they are equipped with bright displays, and information about the state of the system can be directly transmitted to the ship’s computers.

  • For active cathodic protection systems with amperage up to 800 amperes
  • Cost-effective management of even the largest systems.
  • The combination of computerized displays, alarms and information systems.
  • Ability to communicate with on-board computer systems.

Cathelco Anodes

Straight Anodes C-Max Series

They are mainly used for the stern of the vessel in systems with a current strength of 50 to 300A. The conductive part is one or more titanium pipes coated with an alloy of metal oxides. The pipe is mounted on a substrate of durable but lightweight ABS plastic.

Dimensions: 740mm × 400mm
Weight: 7 kg


C-Max Series Disc Anodes

The shape of the anode reduces the risk of physical damage and provides stable hydrodynamics in the bow of the vessel. Low profile anodes prevent contact with the anchor chain. The conductive surface is made of an alloy of metal oxides on a titanium substrate. The edges of the anode are also protected with a rubber rim. It is possible to replace the anode without docking with the help of divers.

Weight: 4-9 kg


Elliptical anodes for ice class ships


In the future, elliptical anodes will be delivered only to ice-class vessels. These anodes are thicker than usual and are equipped with additional protective panels. The conductive surface of the anode is recessed in the shell and has a thick titanium coating in case of contact with ice.

Weight: 8-17 kg


Minitek Series Anodes for Steel Enclosures

Minitek anodes are used to protect the hull of steel on small vessels or yachts. Elements of execution from alloys of metal oxides. The compact design allows you to not take up much space for installation and save the contours of the vessel.


Alutek Anodes Series Anodes for Aluminum Enclosures

Alutek anodes are used on aluminum hulls on small vessels or yachts. Elements are made of platinum titanium (Pt / Ti). For these anodes, a dielectric coating and a special rubber dam are used.

Cathelco Test Electrodes

Control electrodes are necessary to measure the electrical potential between the housing and the water, since the effectiveness of the protection depends on this. The readings are transmitted to the control panel, which automatically regulates the current supplied to the anodes.

The control electrodes are made of zinc or silver and are installed in a recessed position. To do this, the kit includes installation products and gaskets that seal the hole in the housing through which the electrode is connected to the circuit.

Cathelco Shaft Grounding System

Even on ships with an active cathodic protection system or with sacrificial anodes, the propeller shaft bearings are subject to corrosion. This is because the rotating shaft is electrically separated from the housing by lubricants in the bearing housing and the use of non-metallic bearings.

This can be fixed with a sliding washer on the screw shaft, which is electrically connected to the housing. Cathelco produces complete propeller shaft grounding arrangements consisting of a pair of high silver graphite brushes mounted in a balanced frame that rotates on a copper sliding washer with a pure silver track. This combination provides optimal electrical contact.

Cathelco also supplies dedicated compact millivoltmeters to measure potential between the shaft and housing and evaluate system performance.

Silver graphite brushes

Graphite brushes included in the design of propeller shaft grounding systems require regular replacement. Bulk brush orders are more profitable and provide permanent shaft protection.

  • During normal use, the brushes must be replaced every 3-6 months.
  • Bulk orders save time, money, and provide easy replacement.
  • For bulk orders discounts apply.

Vessels are longer than 200 meters.

Superimposed current electrochemical protection systems for the bow and stern of supertankers, bulk carriers, container ships and large sea vessels.

To ensure a smooth surface of the hull in the bow system, round or elliptical anodes with a current of about 100A are usually used, installed on the left and right sides. Power can be supplied from modular or thyristor control panels.

Linear loop anodes are ideal for installation on large commercial vessels, as they provide high output from a relatively small surface. Since they have a powerful output, a single 300A line-loop anode mounted on each side of the housing provides effective protection. Alternatively, linear anodes may be used. In general, thyristor control panels are used in the stern systems of large vessels, as they combine the cost-effectiveness and complexity of information systems.

Tunnel cathodic protection systems for bow and stern

Exceptionally effective system to combat corrosion of the front and rear steering tubes.

Cathelco has developed a unique protective system to protect the stern and bow tunnel from corrosion.

Cathelco systems provide highly accurate corrosion protection for up to 15 years, which is constantly monitored. The system includes a set of anodes and control electrodes mounted flush with the housing and connected to a control panel that automatically regulates the anode current.

The system operates continuously while the ship is at sea, and when the propeller is turned on in a dry dock, it is automatically turned off using a special safety device installed in the shipyard. This protects bearings and seals against stray current.

Ships shorter than 200 meters

Feed system for small commercial vessels.

To protect the hull of ships less than 200 m in length from corrosion, one feed system of active cathodic protection is enough.

This system usually consists of a modular control panel, which is very compact and easy to install. These panels are based on computerized, interchangeable elements, which provides reliability and ease of maintenance and replacement.

For small vessels it is usually most economical to use recessed anodes in the hull. In this case, round or elliptical anodes are installed on the sides of the casing, as well as the corresponding control electrodes, with the help of which the system monitors the electric potential of sea water. Another advantage of small anodes is that they are easily mounted on any form of housing.