Flex Tunnels, three nozzles and three manoeuvring systems with seven rudders for new tanker Stolt and BASF

Damen Marine Components (DMC) is making a special contribution to the innovative inland waterway tanker that is being built for BASF and Stolt Tankers. This shallow water tanker will be equipped with three manoeuvring systems and a total of seven rudders, which is unique in the industry.

The tanker has a lightweight shallow water design, allowing the vessel to remain operational, even at very shallow water levels. The hull form is equipped with three manoeuvring systems. The outer systems consist of a Three-rudder system with a Flex Tunnel in front, both on the left and right. These flexible tunnels are integrated into the hull and can be deployed and retracted at any time. When deployed, they optimise the water flow to the propellers. If the water depth is sufficient, the tunnels are superfluous and they will be retracted. The centre manoeuvring system has a single rudder to improve course stability. DMC also supplies custom-made control and steering systems.

The shallow water ship will be fitted with a total of seven rudders, which is unique. Leo van Zon, Area Sales Manager of DMC: “The design has shown that the outer drive trains have to do their job with a small propeller diameter at shallow draught. DMC has chosen a solution for this in which the original Three-rudder system compensates for the lack of rudder surface at this small propeller diameter that is offered with a normal propeller size drive and rudder system. The seven rudders in combination with the Flex Tunnels make it a unique ship.”

The ship design was conceived and developed on behalf of BASF by DST Duisburg, the inland shipping research institute that also developed the Flex Tunnel System with DMC. Shipping company Stolt Tankers, one of the largest chemical carriers in the world, will be the owner of the vessel and operate it exclusively for BASF. Stolt has asked project developer Mercurius Shipping Group to build the ship. The tanker is planned to be commissioned by the end of 2022.

The new tanker has a high carrying capacity and with a length of 135 meters and a width of 17.5 metres, it will be considerably larger than most other tankers on the River Rhine. The ship will be fitted with ten stainless steel cargo tanks for the transport of chemicals and be powered by three electric motors.

The development of this innovative design was prompted by the shallow draught on the Rhine at the end of 2018, which compromised the supply of raw materials to BASF in Ludwigshafen. “The predictions are that water levels will become increasingly erratic,” says Maickel Uijtewaal, general manager of inland shipping at Stolt Tankers. “All this is in response to expected shallow water levels in the future. It’s fantastic to be able to realise such a unique project together.”