MOL’s propeller boss cap fins hit 3,500 vessel order milestone

Japanese shipping major Mitsui O.S.K. Lines said that its Propeller Boss Cap Fins (PBCF), marketed by its group company MOL Techno-Trade, has now been ordered for 3,500 vessels.

PBCF is an energy-saving device attached to the propeller of a vessel.

It breaks up the hub vortex generated behind the rotating propeller, resulting in energy savings of 3% to 5% compared to an identical vessel not equipped with PBCF.

Higher fuel efficiency in turn cuts emissions of greenhouse gases (GHGs), reducing the shipping industry’s environmental impact.

PBCF installed on a propeller; Image by MOL

PBCF was co-developed by MOL, West Japan Fluid Engineering Laboratory, and Mikado Propeller Co. (now Nakashima Propeller Co., Ltd.), and introduced in 1987.

It has been installed mainly by Japanese shipowners, and in 2006, orders reached 1,000.

As overseas shipowners and ship operators widely recognized the value of PBCF on the back of skyrocketing bunker prices and growing worldwide awareness of the need for CO2 reduction, the number of orders reached 2,000 vessels in 2011 and topped 3,000 in 2015, MOL said.

MOL Tech calculated that the widening use of PBCF has contributed to a cumulative 42 million-ton reduction in CO2 emissions worldwide.

As explained, PBCF can be installed on a propeller by the bolt only, and it has no moving parts, so it is maintenance-free once the installation is complete.

In 2017, MOL Tech, MOL, and Akishima Laboratories (Mitsui Zosen) jointly developed a new type of PBCF, featuring a refined fin shape and height to further enhance its energy-saving effect. This upgraded PBCF has already been installed on over 300 vessels.

“The development team has moved forward with research on a hybrid version with other energy-saving devices such as the Pre Swirl Fin and Energy-saving Rudder with Bulb Fins, and confirmed synergetic effects in a model test (Smart Wake Ship style), having similar wake flow to a full-scale ship,” the company added.

Effective January 2023, the industry expects the introduction of fuel efficiency standards targeting in-service vessels, mandating the same level of efficiency as newbuilding ships.

Vessels that do not conform to these standards will not be allowed to provide ocean shipping services.