12V46TS-DF-engine-hero
Wärtsilä 46TS-DF dual fuel marine engine

Wärtsilä 46TS-DF delivers unprecedented levels of efficiency and power density across a wide operational range for vessels in every segment.

Get the facts: open the brochure

The flexible Wärtsilä 46TS-DF dual fuel marine engine

Wärtsilä 46TS-DF dual fuel marine engine is fuel flexible and will help you power a more sustainable future. It represents a new generation of medium-speed engines and sets a new benchmark for fuel efficiency and emissions performance.

The Wärtsilä 46TS-DF is suitable for a broad range of vessel types and applications. For example:

  • as a main propulsion engine in diesel-electric, mechanical and hybrid installations.

This engine can be optimised to run

  • at constant speed, or 
  • along a propeller curve.

Who is Wärtsilä 46TS-DF engine for?

Because Wärtsilä 46TS-DF can bring fuel savings and maximise environmental performance, it is an optimal choice for

  • cruise lines
  • ferry operators.

Merchant vessels can use Wärtsilä 46TS-DF as a main engine on board, for example on:

  • medium to large size gas tankers
  • bulk carriers
  • container ships
  • special vessels such as dredgers.
cruise vessel Liberty of the Seas

Wärtsilä 46TS-DF – powerfully ready for future fuels

With its two-stage turbocharging, Wärtsilä 46TS-DF delivers unprecedented levels of efficiency and power density across a wide operational range. It is available in six- to 16-cylinder configurations, corresponding to a power output range of 7.8 to 20.8MW at 600rpm.

Wärtsilä’s proven dual-fuel technology combined with an intrinsically modular design means that the engine can operate on either gas or liquid fuel. It is possible to switch between the two fuels according to cost, availability and local environmental regulations.

For the vessel owners and operators, this flexibility and modularity mean that they can

  • save fuel
  • cut emissions
  • choose potential upgrades in the future, including upgrades for use of alternative fuels.

Key features

  • High power density (1,300 kW / cylinder)
  • Two-stage charge air system for higher efficiency
  • Digital common rail fuel injection system for smoke-free operations
  • Variable valve timing for improved flexibility
  • Thermal insulation to improve safety and minimise loss of radiated heat
  • Fully electrical control devices for accurate and fast control

Key benefits of the Wärtsilä 46TS-DF

  • Efficient and powerful, with high power density (1,300 kW / cylinder)
  • Reliable, with proven and flexible dual-fuel technology
  • Complies to regulations. IMO Tier III compliant in gas and diesel modes when combined with SCR
  • Cuts emissions thanks to the revolutionary NextDF technology
  • Cuts your operational costs because it is efficient and has improved heat recovery
  • Saves on maintenance costs because there are 10% fewer cylinders

Comes with NextDF technology

NextDF offers an innovative solution to reduce engine emissions and comply with increasingly strict legislation. With the NextDF feature included, Wärtsilä 46TS-DF will see a significant reduction of methane emissions. 

The power of NextDF is based on the following:

  • Advanced combustion control continuously adjusts engine settings. This optimises combustion for fuel quality and air conditions, which minimises methane slip
  • Latest valve timing control and injector technologies enhance efficiency 
  • New air-fuel ratio control logic lowers the peak temperature of combustion, which reduces NOx formation – and reduces methane slip even further.

Cutting methane slip brings brilliant benefits to the owner and operator, including saving money by avoiding or minimizing emissions-related penalties, and reducing environmental impact.

Take a closer look at Wärtsilä 46TS-DF

Wärtsilä 46TS-DF is a large-bore engine which takes power density and performance to new heights. Learn more from this short video:

High performance with optimal total cost of ownership

When you want to get the best performance while minimising operating costs, you will want to maintain the vessel’s engines in peak condition. Wärtsilä is here to help you: choose a service agreement and you can be sure to have our specialist support for planning, preparing, and executing maintenance.

Your spare parts will be managed by our team, and a proficient maintenance workforce will be ready to support you with high-quality service. AI-driven solutions and predictive analyses combined with expert knowledge will keep your vessel operating at its best.

A service agreement with Wärtsilä offers genuine peace of mind and lets you concentrate on your primary operations. Learn more about our service agreements.

Wärtsilä 46TS-DF Product guide, 3D models and drawings

What’s the secret to successful collaboration when introducing a new engine?

  • detail image of cruise liner with rescue boats
    Royal Caribbean Group

    When Royal Caribbean Group became the first customer for the new Wärtsilä 46TS-DF engine, they knew the rewards it could bring. But what was needed to make sure that the engine’s full potential could be realised?

    Open the case study

Insights on the topic

Discover these most relevant webinars, articles and case studies – they will build your knowledge of Wärtsilä 46TS-DF and related topics.

Cargo ship at sea
25 Oct 2023 · Webinar
How to reduce methane slip – winning tactics for your maritime business
Watch this interesting webinar and you will learn how to reduce methane slip...
Powering the next generation cruise vessel - cruising the decarbonisation journey
18 Jan 2023 · Webinar
How next-generation cruise vessels can succeed in smart decarbonisation
Webinar on smart decarbonisation for cruise ships. Royal Caribbean Group,...
Wärtsilä 46TS-DF - The power to change
26 Apr 2022 · Webinar
Wärtsilä 46TS-DF – The power to change
Wärtsilä 46TS-DF represents the next generation of medium speed engines, designed to set a new benchmark in...
23 Apr 2025 · Article
5 min read
Seven helpful and unbiased facts to know about methane slip
What is methane slip, why is reducing it essential and what smart solutions are on offer...
innovative NextDF technology
18 Feb 2025 · Article
5 min read
How innovative NextDF technology is an easy way to reduce methane emissions
Searching for a way to dramatically reduce emissions like methane slip?...
17 Oct 2022 · Article
4 min read
Five ways the Wärtsilä 46TS-DF helps you decarbonise now and in the future
Take a peek under the hood of the market-beating Wärtsilä 46TS-DF engine...
Wärtsilä 46TS-DF - The power to change
1 Jun 2022 · Article
5 min read
Wärtsilä 46TS-DF – The power to change
The Wärtsilä 46TS-DF delivers dual-fuel flexibility and record-breaking fuel economy across the operating...
Carnival Victory
12 Apr 2021 · Article
5 min read
Guaranteed asset performance – a win-win for Wärtsilä and Carnival
After seeking new ways to draw even greater mutual value from their partnership,...
ship contruction plan
White paper
24 pages
eGuide: Insider’s guide to ship engines
The insider knowledge from this guide helps you make the best choice of engine for the lifetime of your...

Related products and services

Hand-picked press releases

Reach out to Wärtsilä to discover how Wärtsilä 46TS-DF can enhance your fleet’s performance and sustainability.

Wärtsilä Marine. Let's connect.