Short Review of Customer-made Fouling and Damage

Prevention

Systems for Ship Hulls and Associated Technologies

LimnoMar

Last update February 2020

The following should deliver a rough overview of the fouling prevention system in use and on the

market to demonstrate the most dominant systems and those of minor application. Unique fouling

prevention solutions are rare, if existing at all. The selection of an effective and vessel-tailored

fouling prevention system should fulfil the following criteria: Minimal fouling on current exposed hull

areas and in niches to achieve optimal performance, biosecurity and access to global ports. As

integral part of biofouling management it will reduce emissions, fuel and costs on the long run.

Biocidal SPCs/CDPs

Effective after recommendation by respective paint company according to a defined and constant

operational profile of vessel 60 – 72 months (low to high activity, global waters, restricted lay-off

periods)

Effective after recommendation by respective paint company according to no defined and varying

operational profile of vessel, has be combined with regular in-water cleaning after a couple of month

depending on activity level, traded waters and service speed, appropriate, smooth cleaning may only

remove the leached layer

Precautious measurements: Additional paint layers may have to applied to compensate abrasion due

to cleaning

Products: More than 1,400 registered at Lloyds List, standard fouling prevention systems

Biocide-free SPCs

Exclusively effective after recommendation by respective paint company according to clearly defined

operational profile of vessel which will be kept 60 months (low to high activity, global waters,

restricted lay-off periods)

Products: One product of one company with four variations related to operational profiles of vessels

Foul Release Coatings, biocide-free

Effective after recommendation by respective paint company according to operational profile

preferably for vessels with high activity, high service speed and short lay-off periods (ferries, offshore

service vessels, container ships with predictable operational profile

Effective without damage over 60 months

Vessels with varying traded waters, low service speed, low activity level and extended idle periods

regular softly cleaning necessary to avoid biofilm formation and stronger adhering bryozoans and

tube worms

Due to fragility mechanical impact protection by oversized fenders (cruise ships), or lateral protecting

bulges (ferries), no service in drifting ice

Fig. 1 Foul release coatings, silicone based

Fig. 2 Oversized fenders to protect foul release coatings in port

Fig. 3 Lateral bulge to protect the hull and underwater hull coatings on ferry

Foul Release Coatings, biocidal

Foul release coatings, based on silicone backbone with incorporated biocide in extruding hydrogel

Effective after recommendation by respective paint company according to operational profile

recommended for vessels with low activity, low to medium service speed and extended lay-off

periods (bulkers, tankers, cruise ships)

Effective without damage over 60 months

Due to fragility mechanical impact protection by oversized fenders (cruise ships), or lateral protecting

bulges (ferries), no service in drifting ice

Products: 2 products

Mechanical Impact Coatings

Glass fibre or glass balls enforced epoxies

At boot-top for vessels with extended container ships, bulkers, tankers with frequently varying

loaded draught and for flat bottom of vessels operating near soft sediment seabed

Fig. 4 Fender damage on boot-top coated antifouling paint, container ship

Fig. 5 Damage on boot-top coated with antifouling paint, tanker

Fig. 6 Mechanical damage (abrasion on flat bottom of vessel operating in shallow waters near or in contact

with soft bottom of seabed

Vessels with large boot-top area: Container ships, tankers, bulkers

Products: Couple of products frequently in use with antifouling paint on top

Hard coatings without any foul release properties

Glass fibre or glass globules enforced epoxies, no different to most of anti-corrosive paints, some

with ice-class

No inherent fouling protection, coatings have to be cleaned weekly, otherwise strongly adhering

macrofouling will develop which can be removed either by abrasion of the upper layer of the coating

or by hydro-blasting (min. 1,000 bar) with remaining base plates of barnacles and basic attachment

of other fouling organisms

Recommended for fresh water or vessels with defined operational profile permanently trading

between fresh-, brackish- and sea water, vice versa at high activity

Fig. 7 Hard coating after one year in service, before cleaning

Products: 3 -4 products, offered as cleanable coatings, essentially not different from glass fibre

enforced anticorrosive epoxy coatings

Hard Coatings with foul release properties

Hard coatings which withstand impact of cleaning by rotating brushes or hydro-jetting but possessing

inherent properties to reduce the adhesion of fouling organisms

Can be cleaned and should be cleaned according to in-water inspections and foul degree, most

favourable to be cleaned in the biofilm stage

Products: 2 products

Cleaning Technologies

Cleaning without any collection and filtration

Majority of in-water cleaning companies use diver steered cleaning tools with rotating brushes with

different stiffness

More than 30 companies globally active

Cleaning with own collection and filtrations system

An increasing number of in-water cleaning companies use divers steered cleaning tools with rotating

brushes or ROVs using hydro-jetting. Collected fouling is concentrated in a bag or pumped to a

filtration and treatment unit

Approx. 6 companies globally active

Fig. 8 In-water cleaning toll with rotating brushes, collection- and filtration system

Filtration Technologies in combination with In-Water Cleaning

Ballast water treatment facilities on board or mobile systems which can be moved inside of ports or

between adjacent ports

Systems which meet the D2 standard and are certified will offer the most sophisticated filtration

technology.

To avoid connectivity problems between cleaning tools with collection systems via water draining

tube, it may be an option to pump the water with the removed fouling organisms in a barge, one

shell tankers out of service etc. To pump the effluents in an intermediate storage would either allow

to collect water from several cleaning actions or in cases when the amount of water to be filtered is

to voluminous to get ready before the vessel has to leave the port

Fig. 9 Mobile blast water treatment facility

Marine Growth Protection Systems (MGPs) for niche areas

If accessible sea chests, thrusters and stabilizers are coated with those antifouling paints as applied on the hull

In addition cathodic protection, ultrasound and enclosure systems for the cooling system to be filled in port

with hot water, preferably freshwater

Products using copper anodes: 3 at the market

Products using ultrasound, UV-light and heat: 10 products