As explained, fouling accumulating in vessels' hull dramatically increases drag, which results in high fuel consumption and makes it harder to achieve climate targets.

An efficient ship painting requires two decisive factors: a smooth surface and the paint application itself. After all, the better the hull is cleared of its old layers of paint, the more evenly the new layers of paint can be applied to the part of the hull below the water line.

For the best-possible application of paint, the individual layers must be applied exactly at right angles to the surface, as this is the only way to minimise the overspray – i.e. the spray mist that makes the surface next to the section being worked on rough.

Both are a problem with traditional application by hand, as the staff in the shipyard varies considerably in terms of experience and qualifications,

...explains Jan-Evan Lütje, a shipbuilding engineer in Hapag-Lloyd’s Technical Fleet Management.

In shipyards in Hamburg, Marseilles and most recently Singapore, Hapag-Lloyd tested the so-called Hull Treatment Carrier (HTC) coating on a total of nine ships.

The system from the Austrian manufacturer Palfinger is made up of several automated units that travel along the side of the ship’s hull while it is in dry dock. Its job is to remove the old layers of paint from the hull with extremely high water pressure and then to evenly apply new paint.

The shipyard staff works by hand on the bulbous bow, below the bilge keels, at the propeller apertures, and on the flat bottom.

The HTCs can each apply around 600 to 800 square metres of paint per hour, which means it only takes a few hours for one coat of paint.

We can ensure a certain level of quality with automated application systems, and the system is less harmful to the environment. The performance indicators show that the smoother surface results in both lower fuel consumption at the start and a greater resilience to fouling over the entire 60 months,

...Lütje says.