Propeller Boss Cap Fins (PBCF)

PBCF (Propeller Boss Cap Fins) is an energy-saving device installed on the hub of a vessel's propeller. It improves propeller efficiency by weakening the hub vortex generated behind the rotating propeller, reducing fuel consumption by up to 5%. On a large container ship this equals a 9,000-ton reduction in annual CO2 emissions. PBCF was co-developed by Mitsui O.S.K. Lines, West Japan Fluid Engineering Laboratory and Mikado Propeller, and sales began in 1987.

Key features

• Fuel consumption reduction of up to 5%
• Underwater noise reduced by 3 to 6 dB in a specific frequency range, confirmed by model tests
• Selected as a vessel noise reduction technology in the Port of Vancouver's EcoAction Program
• Short-Bodied & Specialized Design PBCF: shortened cap length for vessels with narrow clearance between the rudder bulb and the propeller boss; over 2.0% fuel efficiency improvement in CFD analysis, even on vessels already fitted with energy-saving fins and rudder bulbs

Applications

Newbuild and existing merchant vessels, including container ships and LNG carriers. The Short-Bodied design was first installed on an LNG tanker in 2025.