27. May 2021 | Coach Solutions

Hull fouling is one of the most common reasons why a vessel is underperforming as it is having a detrimental impact on a vessel’s hydrodynamic performance and hence the relationship between speed and fuel consumption. Besides having a financial negative impact for a ship owner, it also has a negative impact on the environment since fouling is causing additional fuel consumption.

Hull fouling

Let´s first have a look at what fouling is. When a vessel is leaving a shipyard as a newbuilding or after a drydocking the bottom of the vessel has been coated with an anti-fouling paint which makes it much harder for the vessel to be fouled. However, the anti-fouling paint will generally only be active when the vessel is sailing due to the water flow around the vessel. When a vessel is idle the anti-fouling paint will no longer have a significant effect.

There are two types of fouling:

  • Macro fouling is large, distinct multicellular organisms visible to the human eye, such as barnacles, tubeworms, mussels, fronds of algae or other large attached or mobile organisms.
  • Micro fouling is a layer of microscopic organisms including bacteria and diatoms and the slimy substances they produce. Often referred to as a ‘slime layer’, microfouling can usually be removed by gently passing a finger over the surface.

Micro fouling will often disappear once the vessels start sailing again and the anti-fouling paint is activated, however this is not the case with macro fouling. It needs to be removed with hull cleaning.

Hull cleaning

Hull cleaning is normally carried out by experienced diving companies which have the knowledge and equipment for such operation. When the cleaning is being carried out it is very important not to damage the anti-fouling paint by using excessive force. As a “rule of thumb” a vessel can be cleaned 2-3 times before the anti-fouling paint loses its effect or is worn off entirely

The hull cleaning operation is carried out by using specialized equipment – typically by using a “brush kart” or a “waterjet kart”.

A “brush kart” is operated by a diver and it is normally powered by a electric hydraulic power pack, powering two or three brushes depending on which area of the hull that has to be cleaned. Depending on the type of fouling and painting various types of brushes are being used. Brushes range from soft silicone brushes to a combination of hard silicone and steel wire brushes when extreme hard and large barnacles need to be removed.

Machines using waterjets is the newest way of cleaning a hull. The water pressure is adjusted according to the fouling type allowing for an effective cleaning and at the same time with least possible damage to the anti-fouling paint. A “waterjet kart” is controlled by a land or ship-based operator who are using cameras mounted on the cleaning machine to control and direct the “waterjet kart”

Example of a hull cleaning performed by using a brush kart: https://www.youtube.com/watch?v=pN1kGrV8CqI

How can our solutions help you?

The COACH Solutions vessel performance software can advise you of the current hull performance of a vessel allowing you to determine when it is time to make a hull cleaning.

The Performance Team from COACH Solutions will create what we call a “digital twin”. We call this performance indicator “speed percentage” and it describes how a vessel should be able to perform in optimal conditions with no fouling. This data is compared with actual performance data deriving from noon reports and any variance will be categorized as a performance loss.

Our vessel performance software determines if and by how much a vessel is under performing and calculates how much fuel and emissions you will be able to save if a proper hull cleaning is carried out.

What kind of savings are we talking about?

The above graph is showing a vessel’s actual performance over time (the blue trend line) A “speed percentage” of 100% is based on optimal hull performance of a vessel. The left side of the graph is showing that the performance of the hull decreases over time from 93% to 90% before a needed hull cleaning is carried out.

The right side of the graph shows the immediate and obvious effect of the hull cleaning. The hull performance is improved from 90% prior to 98% after the hull cleaning.

A vessel with a 10% hull under performance is by “rule of thumb” using up to 25% to 30% more fuel – i.e., a vessel using 50 metric tonnes of fuel per day with no fouling is using 12-15 metric tonnes of fuel extra per day with a 10% hull under performance. With today’s bunker prices this example is resulting in a daily loss of USD 6,000-7,500! This is not petty cash….

Let COACH Solutions help you optimizing your vessel performance resulting in lower fuel consumption and emissions – contact us at sales@coachsolutions.com to hear more.

Recent
Popular

15. June 2021 | Coach Solutions

Meet a COACH – Thomas Hechmann

Here at COACH Solutions, we are very proud of our most valuable and greatest assets – our employees. Without them – no COACH Solutions. We have interviewed Thomas Hechmann, our newest “addition” to our Sales Team at COACH in Copenhagen. He brings a vast amount of commercial shipping experience – mainly form the tanker and […]

27. May 2021 | Coach Solutions

Hull Cleaning and Performance Monitoring

Hull fouling is one of the most common reasons why a vessel is underperforming as it is having a detrimental impact on a vessel’s hydrodynamic performance and hence the relationship between speed and fuel consumption. Besides having a financial negative impact for a ship owner, it also has a negative impact on the environment since […]

18. May 2021 | Coach Solutions

Meet a COACH – Ulla Knudsen

Here at COACH Solutions, we are very proud of our most valuable and greatest assets – our employees. Without them – no COACH Solutions. This time we have interviewed Ulla Knudsen, who is now part of our Performance Department. The team is like the “glue” within COACH Solutions – it is the natural link internally […]

29. April 2021 | Coach Solutions

Meet a COACH

Here at COACH Solutions, we are very proud of our most valuable and greatest assets – our employees. Without them – no COACH Solutions. We have interviewed Abhinesh Nandan, who is Team Leader of our Vessel and Administrative Support Team. The team plays a very vital role since they are in the forefront when a […]

18. March 2021 | Coach Solutions

Online Weather Routing – Why does constant recalculation create value?

Voyage planning has existed ever since sailing became a mean of transportation. Owners and charterers have always tried to optimize the value of fuel against the value of time. Should you arrive earlier or slow down and save bunker? How can we make sure the vessel arrives on time without taking too much risk? Today’s […]

18. November 2020 | Coach Solutions

Why is weather routing so important?

The aim of weather routing is to achieve optimum speed in order to perform the voyage as energy efficient as possible reducing bunker consumption while providing the safety of ship, crew and cargo. The IMO has publicly states that utilizing weather routing services reduces fuel consumption by up to 3% and even further with larger […]

18. January 2021 | Coach Solutions

Monitor Cylinder lube oil consumption

Cylinder lube oil consumption is one of the most overlooked consumers in fleet performance management. With saving potentials anywhere between 5-10% and often higher there is great value in monitoring the consumption and taking action. Over-lubrication does not only directly impact your profit and loss it also has a negative technical impact on your equipment. […]

1. July 2020 | Coach Solutions

Kongsberg Digital acquires COACH Solutions

Kongsberg Digital has acquired COACH Solutions, a leading supplier of software solutions for vessel performance and monitoring. COACH’s vessel performance monitoring system was developed by Danish shipping company Clipper Group. In 2016 COACH was established as an independent company – COACH Solutions ApS – which has grown rapidly. Its software currently has over 900 licenses […]

12. September 2019 | Coach Solutions

COACH Solutions releases IMO 2020 module

COACH Solutions releases IMO 2020 module COACH Solutions have, in close cooperation with our dedicated clients, developed a simple overview to help operators manage the increasing demands posed by the 2020 global Sulphur Cap. In short, it gives the operator a constantly updated overview of which fuel types are on board the vessel, in which […]

23. September 2019 | Coach Solutions

COACH Solutions launch updated web portal

COACH Solutions has launched an updated web portal to serve existing and new clients. The updated web portal helps the clients continue being updated on the performance and current status of their vessels. The site offers an even more user-friendly navigation platform as well as increased responsiveness. In addition, the back-end for the market leading […]

Related articles