Damen has been looking at ways to promote sustainable shipping for years. Several years ago, former Damen shipyard Bodewes participated in the PELS
Project (Project Energy-saving air-Lubricated Ships) with Marinvention and the Maritime Research Institute Netherlands (MARIN) as partners.
PELS originally focused on air lubrication technology using push barges. The project reached a real milestone when the project partners decided switch
to bottom construction. This resulted in a new type of air lubricated ship called ACES (an acronym of ‘Air Chamber Energy Saving’). ACES has
since been patented by Damen and Marinvention.
Testing a diverse conditions
Model tests were undertaken at MARIN’s test basins in Wageningen, the Netherlands. Tests were also carried out along the River Rhine and other
inland waterway locations to investigate various loading conditions. Damen’s R&D team and Marinvention developed a totally new concept that used
a corrugated hull construction. After successful model tests the vessel’s traditional flat bottom was changed to the air lubrication construction at
full-scale. Testing continued in diverse sailing environments: deep and shallow waters as well as facing up and down river.
Annual savings of 15%
The system’s efficiency depended on the sailing profile. Results, and therefore fuel savings, improved at lower speeds. Results varied between 5%
and 40% fuel savings, with overall annual savings calculated to be 15% with a normal sailing profile.
New type patented
There has been a lot of research into all kinds of air lubrication systems – none successful up until now. We are very proud to have developed the
first air lubricated ship. It is a completely new design that offers many possibilities. The construction itself is very simple and easier to build than
the original double-bottomed construction. The corrugated profiles are welded to the plates – making the welding process easier. And it turned out
that this new corrugated construction was incredibly strong.
Furthermore, Marinvention discovered that it was much easier to make a corrugated bulkhead for longitudinal sailing directions. The height of the
corrugations is where the strength lies – there is less wet area because the gaps are filled up with air. There is also a system underneath the hull
which allows a small amount of air onto the propeller – something that reduces propeller vibrations.
Savings from day 1
This system is the first to offer realistic fuel savings. Operators choosing this design on a new build vessel have the
potential to save a lot of money right from the first day of sailing. It also economically viable to carry out the works during a bottom repair or if
companies want to change the CO2 footprint of an existing ship.
Possibilities for seagoing ships
As well as launching ACES, the partners are investigating using this type of bottom on a seagoing vessels. After looking at a 360-metre container
feeder, they will also look at the potential for the tanker industry. There are several challenges to be addressed when it comes to the tanker market, such
as the ADN regulations and the bottom construction of ACES.