MOL Techno-Trade introduces a short-bodied & Specialized design PBCF (Propeller Boss Cap Fins), an energy-saving device that can be installed on vessels with narrow clearances between the rudder and the propeller.

It has been more than 38 years since PBCF was commercialized and MOL Techno-Trade has been involved in its development and sales for a long time, leading to the installation of PBCF on more than 4,400 vessels worldwide. Using the knowledge and experience gained over these many years, MOL Techno-Trade has now developed this short-bodied and Specialized Design PBCF. This product has a shortened body (cap length) to solve this problem and enables installation in extremely narrow clearances on vessels where the distance between the rudder bulb and the propeller boss is narrower due to the larger rudder bulb, making it difficult to install Advanced PBCF.

In addition to reducing the hub vortex, the PBCF increases the fuel-saving effect by reducing torque or increasing thrust due to the fins, but as the rudder bulb has the effect of eliminating the hub vortex, PBCF with rudder bulb has to increase the fuel-saving effect by the fin effect alone. Furthermore, in the case of short-bodied PBCF, it is more difficult to increase the fin effect due to the narrower space available for fin mounting. A possible way to increase the fin effect is to increase the fin height and fin area, but expanding the fins in the height direction also increases the fin resistance, which has the opposite effect. Therefore, CFD calculations were used to optimize the fin pitch angle, fin height and fin shape.

The results of the CFD (Computational Fluid Dynamics) analysis confirmed that the special shape of the PBCF improved fuel consumption by more than 2.0% even on vessels already equipped with energy-saving fins and rudder bulb.

In the case of ships with rudder bulb, including oversized vessels, installation of PBCF on almost half of the vessels had been abandoned due to insufficient clearance, but with the introduction of this short-bodied special shape PBCF, it is expected that PBCF installation will expand to a wide range of ship types.