Wärtsilä transverse or tunnel thrusters WTT English Wärtsilä portals Home Energy Marine Company Insights Home Marine Products and solutions Propulsors and gears Thrusters Wärtsilä Transverse Thrusters Wärtsilä transverse thrusters WTT Transverse thrusters provide a side force that supports mooring operations and station keeping. Wärtsilä WTTs deliver superior hydrodynamic performance for high thrust - diameter ratio. Contact us Wärtsilä transverse/tunnel thrusters WTT Transverse thrusters, also known as tunnel thrusters, bow thrusters or stern thrusters, provide a side force, or transverse thrust, to support mooring operations or station keeping. Wärtsilä WTTs have compact dimensions, yet they deliver high thrust. They are available in a range from 400 kW to 5500 kW and are an excellent choice for ships such as: merchant vessels cruise vessels offshore support vessels  offshore construction vessels. In auxiliary applications, transverse thrusters support the mooring or harbour operations of merchant cargo vessels.  When applied in Dynamic Positioning systems, transverse thrusters extend the DP capability of, for example, offshore supply vessels. Key benefits Superior hydrodynamic performance for high thrust - diameter ratio Robust, reliable and maintenance friendly design Easy installation; high level of integration Maintenance friendly design Wärtsilä ProTouch controls with ergonomic levers and intuitive touch screen displays or push-button panels Download brochure Access 3D models & drawings Application Wärtsilä transverse thrusters are available in a range from 400 kW to 5500 kW for applications in numerous types of ships, including merchant vessels, cruise vessels, offshore support vessels, and offshore construction vessels. Transverse thrusters, also known as bow thrusters, stern thrusters or tunnel thrusters, provide a side force, or transverse thrust, to support mooring operations or station keeping. Transverse thrusters are available for auxiliary or AUX usage, which is mostly applicable with merchant vessels to support harbour manoeuvring and mooring operations. Where the transverse thruster is part of a dynamic positioning (DP) system, the rating for DP use applies. Merchant Cost per kW - 15% reduced cost (CAPEX) per kW* Environmental compliance - Compatibility with environmentally acceptable lubricants (EAL) - Ensures compliance with environmental regulations such as US EPA VGP2013 and DNV CLEAN DESIGN Smaller footprint - Integrated hydraulics and fine filtration ensures longer lifetime for gear, bearings and other rotating components User centric interface - ProTouch control system - bus connections for simplified installation and integration with other equipment control, monitoring and alarm systems  Global support - Service and delivery available when and where you need it Reliability - Robust design for reliable operations in demanding environments and low operational cost Experience - over 1,250 Wärtsilä Transverse Thrusters delivered or on order in the Merchant segment, of a total of 3,250 units Flexible Options – WTT are available in CPP and FPP giving you the option to select the right system to meet your needs. * Compared to a standard Wärtsilä Transverse Thruster with the same propeller diameter. The improvement may vary depending on configuration, fuel, vessel and currency . Options Controllable or fixed pitch propeller upto WTT-40 type; CP propeller for WTT-45 and CT3500 types Manoeuvring (AUX) or Dynamic Positioning (DP) application Redundant pumps and/or lubrication filters Compatible with environmentally acceptable lubricant (EAL) for EPA VGP 2013 compliance or CLEAN notation compliance Face type seal or Air barrier seal for WTT-21 and up Tailor-made tunnel with tunnel ends cut according to hull form and additional circular or longitudinal stiffeners L-drive with intermediate shaft and separate E-motor foundation De-mountable, low noise, horizontal drive variants Package with electric motor and starter Technical info Range and dimensions  Type Electrical Frequency (Hz)  Input Speed (rpm)   Maximum Power 1 Propeller Diameter (D) (mm) Length (L)  (mm)   Weight  2 (kg)     Manoeuvring AUX/Merchant (kW)    Dynamic Positiong DP (kW)       CT/FT125 H  60 50 1780 1480 610 510 600 500 1250 1550 2800  CT/FT150 H 60 50 1780 1480 880 735 780 650 1500 1800 4150  WTT-11 60 50 1180 980 1100 1100 1000 1000 1750 1970 5750  WTT-14 60 50 1180 980 1450 1450 1300 1300 2000 2195 8000   WTT-16 60 50 1180 980 1650 1650 1490 1475 2200 2115 10100   WTT-21 60 50 1180 980 2100 2200 1825 1825 2400 2275 12000 WTT-24 60 50 880 980 2600 2600 2150 2150 2600  2390 13900  WTT-28 60 50  880 735 3000 2800 2400 2400 2800 2970 20200 WTT-32 60 50 710 735 3300 3300 2800 2800 3000  3285 25400 WTT-36 60 50  710 735 3600 3600 3200 3200 3200/3300  3350 29400/29700 WTT-40 60 50 710 735 4000 4000 3600 3600 3400 3520 32800 WTT-45 60 50 710 735 4800 4800 4050 4050 3600  3800 40400 CT3500 60 50 590 590 5500 5500 5000 5000 4000   4300 63700  1 Maximum power level is valid for uni-directional rotation. Depending on propeller type and class society, lower power levels may apply. 2 Version with CP propeller including a standard tunnel with E-motor support., excluding E-motor. Weights and dimensions Power range Did you know? The grid matters Discover Elogrid by Wärtsilä, a unique solution for tunnel thrusters on ships, optimised and customised to add thrust force and save fuel in transit mode. This special grid solves the big problem associated with a conventional grid. Like any grid, it will save fuel in transit mode, but the ship will not suffer a loss of thrust force. On the contrary, this special grid will increase the thrust! Learn more Press releases 11 Jun 2025 · Trade press release Wärtsilä hybrid propulsion solution to optimise efficiency and enable zero emissions for four new Dutch vessels 12 Feb 2025 · Press release Wärtsilä and Elomatic sign licensing and cooperation agreement on Elogrid™ technology 23 Apr 2024 · Press release Six new Sallaum Lines vessels to drive sustainability with Wärtsilä solutions Product hologram Articles 9 May 2023 · Article 4 min read How the right bow thruster can increase efficiency and save you money Choosing the cheapest bow thruster may be a costly mistake. Learn the three... Propulsion Decarbonisation and future fuels Propulsion Decarbonisation and future fuels 14 Sep 2021 · Article 6 min read Helping power the Chinese windfarm construction boom with Wärtsilä transverse thrusters Wärtsilä’s highly efficient transverse thrusters ensure... 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Read more Reynaert The Reynaert entered service in 2007. The major part of the pumping power is delivered by the three Wärtsilä 6L26 engines. The ship is also equipped with two Wärtsilä controllable pitch propellers, one Wärtsilä transverse thruster and Wärtsilä propulsion controls. Read more More Transverse Thrusters references Wärtsilä Marine. Let's connect. Contact us Energy Marine Insights About Careers Media Investors Sustainability Contact About Wärtsilä Wärtsilä is a global leader in innovative technologies and lifecycle solutions for the marine and energy industries. We emphasise innovation in sustainable technology and services to help our customers continuously improve their environmental and economic performance. © 2026 Wärtsilä Privacy notice Cookie notice Terms of Use Subscribe