First ship with Flex Tunnel commissioned into service

The first ship outfitted with the Flex Tunnel was named Friday, August 14th in Duisburg. The Rhenus Duisburg, the new barge combination from shipping company Rhenus PartnerShip, has been put through extensive tests and trials. Much data has been collected so as to establish the appropriate and ultimate efficiency of the Flex Tunnel. The system developed by Van der Velden offers advantages for barges in terms of speed, capacity, propulsion, manoeuvrability and fuel economy.

Without Tunnels

Flex Tunnel is an innovative fold-tunnel system designed specifically for inland waterways. Fitted with conventional tunnels, loaded barges sail in deep water for an average of 80% of the time. Then the use of a tunnel system is unnecessary and leads to additional resistance, with reduced propulsion and therefore higher fuel consumption. Van der Velden’s Tunnel system offers the solution, because the system is only in action when the vessel is unloaded or in shallow water.

The difference between the Flex Tunnel and conventional tunnel systems lies in the fact that the Flex Tunnel makes it possible to sail without tunnels in deep water, like the ARA area. In fixed tunnels, which are installed on most vessels, this is impossible. Navigating without tunnels vastly reduces the resistance, and this in turn provides better fuel economy.

Innovative in all areas

The innovation of this system is not just the ability to sail without tunnels. Van der Velden has also focused their attention at improving the speed whilst using tunnels. The Flex Tunnel ensures that enough water, without air bubbles is channelled towards the propeller. The tunnel has an airtight seal on the jet tubes, which allows larger propeller diameters to be used. The possibilities in the field of hull design are also increased, as fixed tunnels are no longer necessary. This allows further hydrodynamic optimisation. Through the application of the Flex Tunnel the entire design can be tailored to the operational profile and the area where the ship will operate. It is this radical change of design that has propelled the Flex Tunnel system as one of the four candidates for the Maritime Innovation Award 2015, which will be presented at the Maritime Awards Gala in November this year.

The Rhenus PartnerShip Push-barge combination

The German shipping company Rhenus PartnerShip have asked the Development Centre for Ship Technology and Transport Systems, to develop a push-barge combination for transporting coal from Rotterdam in the Netherlands to Lünen in Germany. The vessel will travel with one or more linked barges, but also has to be able to travel along the Rhine with two extra barges on the sides. This calls for a solution for both loaded and unloaded cruising in a mixture of shallow and deep water. Here the Flex Tunnel comes into its own.

Navigation Tests

During the Rhenus Duisburg trials, the Flex Tunnel proved to be fully functional. The reduced resistance on the ship at the collapse of the tunnel system yielded a fuel saving of approximately 10%, whilst sailing in deep water with full loads. This level of performance more than satisfies the high expectations. In addition to the installed Flex Tunnel, Rhenus PartnerShip has also opted for the use of the friction reducing Dolphin Xr++ rudder. This is combined with matching spoilers and a trim plate.

In the following months more tests will be conducted, which will test the performance of operating with full loads in shallow water and how the Flex Tunnel reacts to empty ballast, in both deep and shallow water.

Van der Velden Marine Systems B.V. congratulates Rhenus PartnerShip on their modern and innovative vessel, and wishes the company and crew a safe voyage on the Rhenus Duisburg.