MAN’s powerful engine chosen for dredger

MAN Energy Solutions has won the contract from Royal Boskalis to supply 3 × MAN 49/60 engines for a 31,000 m³ Trailing Suction Hopper Dredger (TSHD).

Each engine will come accompanied by an exhaust-gas after-treatment system, namely an MAN Low-Pressure Selective Catalytic Reduction (LP-SCR) system, that ensures IMO Tier III compliance. The newbuilding will be built at Dutch shipbuilding company, Royal IHC, at its Krimpen aan den IJssel yard and is expected to enter service in mid-2026.

The TSHD will be diesel-electric powered with two Azipods to allow vessel operation even at shallow draught. All major drives (thrusters, dredge pump, etc.) will be electrically driven and controlled by frequency converters, enabling each system to operate at optimal speed and power. The asymmetric load-sharing results in optimal load distribution over the diesel generating sets with low fuel-consumption and high maneuverability.

The BV-classed main diesel engines will be capable of running on either conventional fuels – like HFO and/or MDO/MGO – or on sustainable fuels, such as biodiesel (HVO and/or FAME). Furthermore, the dual-fuel engines will also be delivered as (green) methanol-ready. As such, the MAN 49/60 will always be capable of meeting NOx Tier III emission limits.

MAN Energy Solutions states that the engines maintain their high efficiency at all times and that there is no fuel penalty when operating the SCR system – especially with HFO – in great part due to the lower temperatures that MAN SCR solutions operate at.

In close cooperation with Royal IHC and Boskalis, the engines have been fitted into an engine-room design similar to those used in previous Royal IHC dredger projects.

The MAN 49/60 successfully passed its type approval test in March 2023 and features a high power-per-cylinder of 1,300 kW, reducing the number of installed cylinders necessary to meet customer power demands. While in this particular project six-cylinder engines are applied, the L-type of the engine can accommodate up to 10 cylinders, which make it capable of propelling ships typically powered by V-engines. The 49/60 is also available as 12V and 14V engine variants.

A key determinant in the choosing of the 49/60 engine was its ability to fulfil the load-acceptance requirements demanded by the TSHD’s diesel-electric propulsion system in diesel mode. The next-generation MAN common-rail system 2.2, in combination with the two-stage turbocharging system used by the engine, enables it to compromise between load acceptance and efficiency.

Additionally, the next-generation SaCoS 5000 engine-automation system enables the engines to fulfil cyber security requirements and offers enhanced remote-support possibilities.

The MAN LP-SCR system provides an in-house developed and integrated solution for MAN Energy Solutions’ entire portfolio of four-stroke medium- and high-speed engines and serves as a standard solution for meeting Tier III emission limits. This SCR technology exploits synergies and competences within the entire Volkswagen Group, such as the AdBlue Technology of Volkswagen Truck & Bus division, and has proven its performance in the automotive field millions of times.

Unlike other SCR solutions, MAN SCR systems do not require a pre-silencer as they have been designed to reduce pulsation and vibration, in the process extending times-between-overhauls. MAN Energy Solutions also offers customised SCR systems on demand and, to date, has sold more than 350 of its own LP-SCR systems for marine newbuilds and more than 20 of its own LP-SCR systems for retrofit solutions.