Propeller retrofitting

Changed operational profiles with varying speeds often lead to non-optimal propeller designs on existing vessels. These propellers have typically been designed for maximum speed and low cavitation. A retrofitting to a more suitable propeller given actual operational conditions can reduce the overall fuel consumption significantly.

Applicability and assumptions

Propeller retrofitting is suitable for all vessel types and ages with operating conditions which deviated from design conditions, especially container vessels and large vessel series. The exchange of the propeller with an upgraded design assures operation at peak efficiency. Included with the price of the propeller itself, a complete analysis to recommend the best-suited propeller for highest efficiency is also included. An engineering analysis should be conducted utilising computational fluid dynamic (CFD).

The lifetime of a new propeller is estimated to be 15 years.

Cost of implementation

The cost of propeller retrofitting with CFD analysis, and a new propeller is assessed to be in the range of $400,000 – $850,000 (USD), heavily dependent of propeller size.

Reduction potential

This measure typically makes the most sense when combined with additional improvements on machinery and the achieved reduction potential is assessed to be in the range of 2 – 6% on main engine fuel consumption.

Typical total fuel consumption saving is estimated to be between 0.5 – 4%.

Other References

1. DNV GL. (n.d.). ECO Retrofit / Overview of different retrofit options
2. Aronietis, et al. (2014). Ship retrofit solutions: economic, energy and environmental impacts
3. Gassmann, et al. (2017). Underwater noise comparison of pre-and post-retrofitted MAERSK G-class container vessels