The Dutch dredging company Royal Boskalis has commissioned MAN Energy Solutions to supply a drive for a new trailing suction hopper dredger.
The scope of supply for the ship with a capacity of 31,000 m³ includes three MAN 49/60 engines. Each engine is equipped with an exhaust aftertreatment system, namely a MAN LP-SCR (Low-Pressure Selective Catalytic Reduction) system, which ensures compliance with IMO Tier III[ds_preview].
The ship is being built by the Dutch shipbuilding company Royal IHC at its shipyard in Krimpen aan den IJssel and is scheduled to enter service in mid-2026.
Ready for alternative fuels
Lex Nijsen – Vice President Marine, MAN Energy Solutions, says: “This project poses special challenges in every respect, as it is a completely customized solution. It is a special honor for us to have been selected as the propulsion system supplier for this unique dredging vessel.”
Marita Krems – Senior Vice President, Head of Four-Stroke Marine & License, adds: “This first order from an established customer for a demanding application is a significant step towards establishing our 49/60 as a widely used marine engine. Thanks to its ability to switch to renewable fuels such as e-methanol and biofuels, the 49/60 contributes to decarbonization and compliance with future regulations.”
The suction hopper dredger is equipped with a diesel-electric propulsion system and two azipods, which enable the vessel to operate even at shallow drafts. All major propulsion systems (rudder propeller, dredge pump, etc.) are electrically driven and controlled by frequency converters so that each system can be operated at optimum speed and power. The asymmetrical load distribution ensures optimum load distribution to the diesel gensets with low fuel consumption and high maneuverability.
MAN engine is methanol-compatible
The main diesel engines of the BV class can be operated either with conventional fuels – such as heavy fuel oil (HFO) and/or marine diesel oil (MDO)/ marine gas oil (MGO) – or with sustainable fuels such as biodiesel (HVO and/or FAME). The dual-fuel engines are also “methanol-compatible” (green). The MAN 49/60 can, therefore, always comply with the NOx Tier III emission limits.
MAN Energy Solutions emphasizes that the engines maintain their high efficiency at all times and that there are no disadvantages in fuel consumption when operating the SCR system – especially with heavy fuel oil (HFO) – due in large part to the lower temperatures at which MAN’s SCR solutions operate.
In close cooperation with Royal IHC and Boskalis, the engines were installed in an engine room design similar to that used in previous Royal IHC dredger projects.
Type approval test successfully passed
The MAN 49/60 successfully passed its type approval test in March 2023 and is characterized by a high output of 1,300 kW per cylinder. This allows the number of cylinders required to meet customer performance requirements to be reduced. While six-cylinder engines are used in this project, the L-type of the engine can have up to 10 cylinders, allowing it to be used in ships that are usually powered by V-engines. The 49/60 is also available as a 12V and 14V engine variant.
A key factor in the selection of the 49/60 engine was its ability to meet the load-carrying requirements of the diesel-electric propulsion system of the hold suction dredger in diesel mode. The next-generation MAN Common Rail System 2.2, in combination with the engine’s two-stage turbocharging, enables a compromise between load absorption and efficiency.
With the new SaCoS 5000 automation system, the engines can also meet cybersecurity requirements and offer extended remote maintenance options.
SCR without pre-silencers
SCR is the most tested and proven system for achieving NOx reduction rates of up to 90%. MAN’s LP-SCR system offers a purpose-built and integrated solution for MAN Energy Solutions’ entire portfolio of medium and high-speed four-stroke engines and serves as a standard solution to meet Tier III emission limits. The SCR technology utilizes synergies and competencies within the Volkswagen Group, such as the AdBlue technology of Volkswagen Commercial Vehicles, and has proven its performance in the automotive sector millions of times over.
Unlike other SCR solutions, MAN’s SCR systems do not require a pre-silencer as they are designed to reduce pulsations and vibrations, thus extending the time between overhauls. MAN Energy Solutions also offers customized SCR systems on request and, to date, has sold more than 350 of its own LP-SCR systems for new ships and more than 20 of its own LP-SCR systems for retrofit solutions.
