Elogrid™: tunnel thruster solution for fuel savings and better maneuverability
Elogrid reduces tunnel thruster resistance and improves side thrust by over 10%. Proven on cruise ships and ferries. Available for newbuilds and retrofits.
Elogrid™ is Elomatic’s tunnel thruster solution that reduces hull resistance from open thruster tunnels while improving side thrust during maneuvering. It is installed in the thruster tunnel openings of the vessel and is optimized using computational fluid dynamics (CFD) analysis based on the specific hull shape and operational profile of each ship. Elogrid is available for both newbuilds and retrofit installations.
Key Takeaways
- Elogrid reduces fuel consumption by 1 to 4% depending on vessel type and operating conditions.
- Side thrust during maneuvering improves by over 10%, verified by independent CFD testing by Bureau Veritas Solutions in 2025.
- Vibration in the thruster tunnel is reduced by approximately 25%, improving comfort aboard.
- Elogrid is installed during regular drydocking, and laser scanning ensures millimeter-level component fit.
- Elogrid has been installed on vessels operated by Carnival Corporation, Viking Line, and others.
How Elogrid works
Open thruster tunnels create two problems that directly affect fuel consumption and vessel handling. When the ship is underway with thrusters inactive, the open tunnel openings add resistance to the hull, increasing fuel burn. When thrusters are in use, standard tunnel grids partially block and disrupt flow, reducing available side thrust and causing cavitation. Elogrid addresses both problems with a single device. The hydrodynamic design reduces the windmill effect in the tunnel when thrusters are off, and optimizes water flow to and from the thruster propeller when they are in use. The result is lower resistance at sea and stronger, more directional thrust in port.
Each Elogrid is custom-designed for the vessel it is installed on. Our CFD team analyzes the hull geometry and thruster configuration, which provides high precision for the custom design.
Measured results
The performance figures below are based on CFD evaluations and real-world measurements from installed vessels.
1-4%
Fuel savings depending on vessel and operation
>10%
Side thrust improvement, confirmed by Bureau Veritas
~25%
Reduction in tunnel vibration
~2 dB(A)
Reduction in airborne noise level
In 2025, Bureau Veritas Solutions Marine and Offshore (BVS) conducted an independent CFD evaluation of Elogrid. The validation confirmed that Elomatic’s CFD results align closely with BVS calculations, with less than 5% difference in both total resistance and side thrust results. BVS confirmed hull resistance reductions at 12, 18, and 21 knots, and side thrust improvement of over 10%.
Vessels with Elogrid
Elogrid has been installed on vessels across several major fleets. Current customers include Carnival Corporation’s XL-Class fleet, Viking Line, and MEYER FASSMER Spezialschiffbau. Several additional vessels are in the design and evaluation phase.
Laser scanning for precise installation
Laser scanning of the thruster tunnel openings captures the exact as-built geometry of the hull at millimeter accuracy. This allows Elogrid components to be manufactured as precision prefabrications, resulting in faster installation with no rework during drydock.
Laser scanning is done during the regular drydocking period. If a vessel has not yet committed to an Elogrid installation, we recommend capturing the tunnel geometry during any planned docking so the data is available when needed. This avoids an additional docking requirement later.
Newbuild and retrofit applications
Elogrid can be specified at the design stage for newbuilds, where it is integrated into the hull design from the outset. For existing vessels, retrofit installation is straightforward and does not require structural modifications to the hull. The CFD evaluation and laser scanning process is the same in both cases.
The payback period for a retrofit installation depends on the vessel’s fuel consumption, operational profile, and fuel price. For vessels with a high proportion of sea time and multiple tunnel thrusters, the return on investment is typically fast.
Frequently asked questions
Elogrid is a hydrodynamic device fitted in the tunnel thruster openings of a vessel. It reduces the additional hull resistance created by open tunnels when thrusters are not in use, and improves the thrust output and flow quality when thrusters are operating. The result is lower fuel consumption at sea and better maneuverability in port.
Fuel savings range from 1% to 4% depending on vessel design, the number of thrusters, and operational profile. Vessels with higher sea speeds and multiple tunnel thrusters tend to see larger gains. Our CFD team can estimate expected savings for a specific vessel before any commitment is made.
Yes. In 2025, Bureau Veritas Solutions Marine and Offshore conducted an independent CFD evaluation of Elogrid. Their results confirmed hull resistance reduction at multiple speeds and side thrust improvement of over 10%, with less than 5% difference from Elomatic’s own calculations.
Yes. Elogrid is available as a retrofit installation and does not require structural modifications to the hull. Installation is carried out during regular drydocking. Laser scanning of the tunnel openings is done first to ensure the components are manufactured to exact fit, which keeps installation time short.
Elogrid is suitable for any vessel with tunnel thrusters, including cruise ships, ferries, RoPax vessels, offshore support vessels, and cargo ships. Each installation is custom-designed using CFD based on the specific hull and thruster configuration of that vessel.
A preliminary evaluation based on available hull data typically takes a few weeks. A full CFD analysis with custom design takes longer and is carried out as part of the project scope. Contact our team to discuss what is needed for your vessel.
Discuss Elogrid for your vessel
If you want to know whether Elogrid is a good fit for your vessels, our team can run a preliminary feasibility study based on basic hull parameters. Contact us to start the conversation.
