What is it?

Propeller surface roughness causes a greater energy loss per unit area than the condition of the hull surface.  To determine the extent of propeller surface roughness, periodic underwater inspections are conducted.  Thus, it is possible that a ship will be operating with significant propeller roughness before that roughness is detected by the periodic inspection. 

How does it work?

To achieve a reduction in propeller roughness and sustain a smooth propeller blade, increased propeller monitoring and condition-based maintenance will be implemented. To assess the propeller surface condition more effectively and understand how that roughness affects fuel use, preliminary inspections will be conducted and a quantitative method for acquiring roughness data will replace the subjective methods currently being employed.

What will it accomplish?

Timely detection and remediation of propeller surface roughness can result in significant fuel savings.

Metric:

Policy Change