Wärtsilä announces 46TS-DF high efficiency medium speed engine

27 April 2022

Wärtsilä announced the launch of the 46TS-DF medium speed marine engine, designed with a focus on efficiency, environmental performance, and fuel flexibility. In gas fuel mode, the engine has the highest efficiency thus far achieved in the medium-speed engine market, according to the company.

The first order for this engine type was placed by Chantiers de l’Atlantique for Royal Caribbean Cruises in April 2021. The engines will be installed on their latest Oasis class ship ‘Utopia of the Seas’. The ship is being built by the shipyard Chantiers de l’Atlantique and will feature six Wärtsilä 46TS-DF engines with Gas Valve Units, NOx Reducer SCR systems, LNGPac and Transverse Thrusters.

The Wärtsilä 46TS-DF is a dual-fuel engine that can switch between gas (LNG) and diesel modes. The two-stage turbocharger system features a higher compression ratio and high efficiency, allowing high power density and efficiency across a wide operational range. The fuel injection system features the fully electronic Wärtsilä Common Rail system, which provides efficiency and smoke-free operation at all loads, even in diesel mode. The engine is IMO Tier III compliant in gas and diesel modes when combined with SCR.

The engine can achieve a brake thermal efficiency (BTE) of up to 52% [5479]. This is a notable improvement over the Wärtsilä 31DF engine, which could achieve a BTE of up to 49.7% in 2019 [4241].

Development of the Wärtsilä 46TS-DF engine has been based on the experience from the Wärtsilä 46, 46F, and 50 engine families. It is available in 6 to 16-cylinder configurations, corresponding to a power output range of 7.8 to 20.8 MW at 600 rpm. It features a modular design, which simplifies upgradability and modifications for alternative future fuels.

Source: Wärtsilä