MAN Engines expands its workboat portfolio

With the new 30-litre MAN D3872 engine, MAN Engines is significantly expanding its engine portfolio in terms of output and displacement. The result is that in-line six-cylinder, V8 and V12 engines from 221 to 1,618 kW (301 to 2,200 hp) with a displacement of 12.4 to 29.6 litres are currently available for light, medium and heavy-duty marine applications.

A key feature of the MAN D3872 30-litre engine is its compactness. The developers were able to retain the connection dimensions of the 24.4 litre V12 engine with the displacement as well as the compact installation dimensions of 1,153mm wide and 1,320mm high. Only the length of the MAN D3872 has been increased by an additional 100mm to 2,335mm.

Additionally, the OEM says the compact dimensions of the MAN exhaust gas aftertreatment system offer a clear advantage in the design of machine rooms.

The development of the MAN D3872 involved numerous test bench trials that followed the development of the MAN E3872 stationary gas engine which has the same basic engine. This gas engine is already in series production and is proving its worth in power and heat generation applications.

A MAN D3872 LE432 engine with 1.650hp has undergone successful field testing in the passenger ferry MN Ischiamar I operated by Capitan Morgan in the Gulf of Naples, Italy. Since then, series production of the engine has commenced.

The V12 engine that was on display at SMM 2024 has an output of 1,213 kW (1,650 hp) at 2,100 rpm, making it suitable for medium-duty applications such as wind farm supply vessels, ferries, passenger ships and fishing boats. Further power variants of the MAN D3872 (1,471 and 1,618 kW or 2,000 and 2,200 hp at 2,300rpm) for light applications have already started series production.

The MAN D3872 has a completely new basic engine that builds on experience gained from the already-established MAN D2862 V12 engine series. It has improved coolant delivery through a new coolant pump and thermostat housing, which the OEM says contributes to the engine’s high longevity. As an optional alternative, the engine is available with an outer skin cooling system instead of the closed cooling circuit.

A key development goal was high power density, so that the most powerful variant, the MAN D3872 LE433, has an output of 1,618kW (2,200 hp), with a dry weight of only 2,720kg and a displacement of 54.7kW per litre.

There are other significant changes: the cylinder head of the MAN D3872 has been redesigned to optimise flow and cooling. The oil supply has new flow-optimizing features in addition to new oil pumps and new oil coolers. The new common rail injection system has an injection pressure of 2,200 bar, and the new MD1+ engine control unit optimises engine tuning. Significant crankshaft changes were implemented, including an increase in its wall thicknesses, optimised bolting, and larger bearing diameters.

The modular exhaust gas aftertreatment system developed in-house ensures that the MAN D3872 meets current strict emission standards such as EPA Tier 4 or Tier 3 or IMO Tier III or Tier II. It reduces fuel consumption by an additional 3-8% and can be fitted with a diesel particulate filter if required.

In addition, the engine – like all engines from the current portfolio – is approved for use with regenerative diesel in accordance with the EN15940 standard in Europe and the US specification ASTM D975 of the American Society for Testing and Materials (ASTM).

In the medium term, further performance increments are planned for the MAN D3872 marine engine in a wide variety of emission levels. Additionally, the MAN D3872 will be followed by another variant for heavy-duty applications rated speed 1,800 rpm which is expected to be unveiled at SMM 2026.