TeamCo has contracted Van der Velden Marine Systems for the delivery of FLEX tunnels for two new inland waterway tankers to be built next year at the company's yard in Heusden, the Netherlands.
Van der Velden will also supply a Barke Optimised Steering System (BOSS) eco system, an intelligent fuel saving system for the ships.
XXL Tankers
The inland waterway tankers will set sail in 2018 and are based on a new hull design. Van der Velden, which will also supply the rudders, adjusted the FLEX Tunnel design to fit the hull. The bunker vessels (135 x 22 m) will become the largest of their kind, hence the term XXL tanker.
According to Leo van Zon, sales director at Van der Velden, this took some work: ‘Especially when the number of propulsion trains was reduced from three to two during the design stage. This meant we lost a third of the rudder capacity. Larger rudders and propellers were needed to ensure good manoeuvrability. This was partly achieved with the FLEX Tunnel.’
More Power, Less Fuel
The FLEX Tunnel is retractable and specially developed for inland vessels. Tunnels are commonly used to ensure optimal water flow to the propellers at shallow draughts, but also increase hull resistance and fuel consumption. Moreover, when loaded, inland ships sail in deeper water conditions (about 85 per cent of the time), during which a tunnel is superfluous.
The FLEX Tunnel is only deployed when sailing in shallow waters to ensure sufficient water flow to the propellers and maintain their efficiency. In this case, it forms an airtight seal to the nozzles allowing for larger propellers and rudders. The airtight seal creates a partial vacuum allowing the water level in the tunnel to rise for a sufficient flow of water to the propellers that stick out relatively far above the water line. This improves propeller efficiency and allows them to deliver more power.
More power from the propellers, means the engines do not have to work as hard thereby saving fuel by approximately 20-25 per cent. Embedded into the vessel’s hull, the FLEX tunnel lowers resistance and further improves efficiency.
BOSS Eco
Van der Velden first introduced the BOSS eco system in May this year. To optimise manoeuvrability when steering manually or automatically, BOSS is able to calculate the rudder forces by measuring the bending of the rudder stock.
The measured values are displayed on a touch panel on the bridge and can be transferred to the ship's navigation system. The panel also indicates current fuel savings and related reduced CO2 emissions.
Through reducing rudder movements, manoeuvrability is improved and sailing on Autopilot mode reduces the overshoots, shortening the travelled distance and so reducing fuel consumption by 10-12 per cent. The BOSS eco system is suitable for all inland waterway vessels, both existing and new builds.
