The Cathelco marine growth prevention system has proved to be an effective and reliable method of eliminating blockages caused by bio-fouling.
- Based on the electrolytic principle, providing continuous and reliable protection without the use of chemicals.
- A dual system combining pipework anti-fouling and corrosion suppression.A range of control panels and anodes to suit vessels of every size.
- Every system custom designed for its particular application ensuring greater effectiveness.
- Automatic operation – requires minimal attention and makes very little demands on crew time.
- Easy installation – anodes can be installed in seachests or strainers at newbuilding or retrofit.
- Environmentally friendly – does not involve the use of chlorine based chemicals or carcinogens.
- Approved by classification societies.
The system usually consists of pairs of copper and aluminium anodes which are mounted in seachests or strainers and wired to a control panel. In the case of cupro-nickel pipework, a ferrous anode is used instead of the aluminium anode.
In operation, the copper anode produces ions which are carried by the flow of seawater, creating an environment in which barnacles and mussels will not settle or multiply.
By introducing copper ions in very small concentrations, around 2 parts per billion, the Cathelco system interrupts the settlement sequence of mussel and barnacle larvae.
Instead of adhering to the surface of seachests, strainers and pipework, the larvae pass harmlessly through the cooling water system to the point of discharge.
Without anti-fouling protection, pipes become encrusted with organisms leading to partial or total blockages which reduce the efficiency of the seawater cooling system.
A dual action system
The action of the copper ions is assisted by aluminium hydroxide created by the aluminium anodes which flocculates the released copper from the copper anodes.
This highly gelatinous copper-aluminium hydroxide floc is carried throughout the system and tends to spread out into the slow moving areas closer to the pipe surfaces where marine larvae are most likely to settle.
As a result, marine growth larvae do not settle, instead passing direct to discharge. At the same time, a cupro-aluminium film is built up on the internal surfaces of pipes to suppress corrosion. In this way, the system has a dual action protecting seawater pipework against bio-fouling and corrosion.
Seachest or strainer mounted anodes
When systems are installed at newbuilding, anodes are generally fitted in the seachests using special sleeves or flange mountings.
Alternatively, if systems need to be installed prior to scheduled drydocking, the anodes can be mounted in the seawater strainers. This also simplifies replacement when anode renewal becomes necessary.
In special cases, where the Cathelco system supersedes existing chemical based anti-fouling equipment, the anodes can be mounted in treatment (electrolysis) tanks in order to economise on the installation costs by utilising existing pipework.
- Steel pipework – protected by copper and aluminium anodes.
- Cupro-nickel pipework – protected by copper and ferrous anodes.
- Seachest mounted anodes – generally installed at newbuilding and are replaced at drydocking.
- Strainer mounted anodes – can be replaced at any time when the vessel is alongside.
- Electrolysis tanks – can be used to replace chemical systems or in specialised applications where seachest or strainer mounting is not possible.
- Environmentally friendly – does not use chemicals. Generally operates with copper concentrations of just 2 parts per billion.
Make sure you meet the new
EU biocide regulations
Since September 2015, owners and operators of vessels sailing into European waters must ensure that marine growth prevention systems comply with the EU Biocides Regulation (528/2012). Cathelco are one of the few companies listed under Article 95, the official register of Authorised Active Substance suppliers who have been approved by the European Chemicals Agency (ECHA). Therefore, it is important to install genuine Cathelco equipment and anodes.
Failure to use equipment from an authorised supplier may affect the ship’s Green Passport, lead to financial penalties and even imprisonment.