Offshore Vessels Feature MAN L21/31 GenSets for Diesel-Electric Propulsion

Wenchong shipyard in China, part of the CSSC Group, has ordered four shipsets of 3 × MAN 8L21/31 MK2 GenSets in connection with the construction of 4 × 96m C-CSOVs (Construction and Commissioning Service Operation Vessels) operated by DO (Deutsche Offshore Schifffahrt [German Offshore Shipping]).

A CSOV is a specialised vessel designed to provide support services during the commissioning and operation phases of offshore wind farms. DO has innovated this concept with increased flexibility, offering the market enhanced applicability in the construction phase, as well as in the cable-grid sector. The basic design was drafted by Naval Architects Salt Ship Design AS from Norway. MAN Energy Solutions licensee, CMP, will build the engines in China with delivery scheduled from Q1, 2027; the order includes an option for further vessels.

The engines will be delivered as part-load optimised for increased fuel efficiency. They will also form part of an innovative diesel-electric concept that complies with Dynamic Positioning stage 2 (DP2), as set out by the DNV classification society.

Johannes Wolters, Managing Director of Deutsche Offshore, summarised: “MAN Energy Solutions’ L21/31 is a cornerstone in our endeavour to develop a vessel with a minimal environmental footprint. The engines offer us benchmark performance in the here and now, while granting us seamless readiness for our decarbonisation strategy.”

Colin Peesel – Head of Sales & Promotion, MAN Energy Solutions, Germany – said: “These 12 engines represent a very significant contract, amounting to over 20MW of power. The L21/31’s many advantages include its class-high fuel efficiency, and low noise-and-vibration levels. Crucially, it is future-proofed regarding operating fuel. Besides MGO, it is capable of running on biofuels such as HVO and FAME, and it is additionally delivered methanol-ready.”

The vessel design that allows for the future retrofitting of the L21/31 GenSets to methanol operation caters for this to a much higher degree than class notation actually requires. Having introduced substantial methanol infrastructure into the vessel already today will make a future conversion to carbon-neutrality smooth and efficient.

MAN Energy Solutions reports a growing trend within the offshore-vessel segment for construction to take place in China. The company already has a sizable presence in China supporting a broad network of licensee engine builders and a growing portfolio of new engine models. Likewise, its after-sales division – MAN PrimeServ – has a strong, global presence, regardless of where the DO vessels eventually operate.

Hakon Juel Hansen –  Manager Engine Promotion & Business Development – MAN Energy Solutions, said: “We are experiencing increased demand for efficient, competitive engine designs for the Offshore Wind segment, which our portfolio of small-bore propulsion engines is fulfilling, backed up by our MAN PrimeServ after-sales network. With these technically sophisticated offshore vessels, DO is showcasing the adaptability of our engine portfolio.”

About DO

Launched in 2024, Deutsche Offshore Schifffahrt (DO) is positioning itself as an important player in the rapidly growing offshore energy market. DO acts as commercial manager for four ordered special-purpose vessels, which have been ordered by Schoeller Holdings. These Construction and Commissioning Service Operation Vessels (C-CSOVs) are expected to enter service in 2027. The core task of Hamburg-based DO lies in the development of special offshore ships and the commercial operation of these technically sophisticated vessels tailored to the energy market. Technical management will be contributed by Columbia Energy.