A message shared by Gelu Stan with the ANCONAV community puts fresh attention on one of the most practical efficiency levers available to shipping today: upgrading propulsion through advanced propeller design and retrofit energy-saving devices.
Lloyd’s Register’s public report Applying advanced propeller designs to ships suggests this is no longer a niche technical discussion. As owners face pressure to cut fuel consumption and remain compliant with EEXI, CII, EU ETS and FuelEU Maritime, propulsion upgrades are re-emerging as a realistic pathway to measurable savings without waiting for an entirely new generation of ships.
Why propeller performance is back on the investment agenda
Over the last few years, decarbonisation discussions have focused heavily on alternative fuels, digital optimisation and operational measures. Those remain important, but LR highlights a basic point: a major share of vessel efficiency is still determined by how effectively power is transferred into the water. That is why propeller redesign, vessel-specific optimisation and add-on propulsion devices are attracting renewed commercial interest.
According to Lloyd’s Register’s summary findings, high-efficiency propellers can deliver fuel savings in the range of roughly 3% to 10%, while established devices such as rudder bulbs may add reductions of around 3.5%, depending on vessel type and operating profile. In a market where every tonne of fuel and every CII performance point matters, those gains are commercially significant rather than marginal.
Demand is rising faster than fleet-wide adoption
Another important signal is the pace of market change. Demand for propeller retrofits and propulsion energy-saving devices has reportedly increased almost four-fold since 2020, showing that owners are no longer treating such projects as isolated experiments. At the same time, adoption across the global fleet is still limited, which means there is substantial room for modernization and a potential first-mover advantage for companies that make technically sound choices early.
For existing ships, the case is not only environmental. It is also commercial resilience. A vessel that burns less fuel, protects its carbon rating and keeps better trading flexibility is better positioned in a market where operating costs and regulatory constraints are tightening at the same time.
Not every retrofit works equally well on every vessel
This is where discipline matters. LR emphasizes that technology selection has to be based on the vessel’s real profile: hull form, typical speed, loading pattern, voyage mix, maintenance condition and shaft-line characteristics. A solution that performs well on one bulk carrier will not automatically produce the same result on another ship type without proper hydrodynamic and operational assessment.
Propulsion retrofits also need to be reviewed alongside secondary effects such as torsional vibration, shaft alignment, underwater radiated noise, cavitation behaviour and the performance losses associated with biofouling. The gap between a successful project and a disappointing one is usually determined not by marketing claims, but by the quality of the technical assessment and the monitoring framework after installation.
What owners, operators and yards should focus on
For owners and operators, the practical takeaway is that propulsion retrofit decisions should be treated as full business cases rather than simple equipment purchases. That means payback modelling, fuel and carbon scenarios, realistic docking windows and a clear view of how the upgrade interacts with other efficiency measures already installed on board.
- audit actual vessel performance and trading profile before selecting the solution;
- use CFD and cost-benefit analysis to validate the retrofit case;
- check implications for vibration, underwater noise and mechanical reliability;
- set up post-retrofit monitoring to verify the savings that were promised.
For Romanian yards, suppliers and technical service companies, the trend also has a commercial side. If the retrofit wave continues, expertise in hydrodynamic analysis, integration work, measurement and post-installation support could become increasingly valuable across the regional maritime market.
In short, efficiency is no longer driven only by slow steaming or route optimisation. It can also come from carefully engineered propulsion improvements, and that makes advanced propeller retrofits a business decision with direct operational relevance.
Editorial source: email sent by Gelu Stan on 2026-05-20 and Lloyd’s Register public materials: Applying advanced propeller designs to ships and Demand for propeller retrofits surge four-fold.
Romanian version: https://www.anconav.ro/ro/elice-avansate-retrofituri-propulsie-eficienta-navelor/