Press Release

ClassNK to releases world-first Guidelines on Composite Propellers

28 August 2015

Tokyo – Leading classification society ClassNK (Chairman and President: Noboru Ueda) has announced that it will release the world’s first Guidelines on Composite Propellers (Part on Manufacturing/Product Inspection) on 31 August.

The strength and corrosion resistance of composite materials makes them widely used in fields such as aerospace, automobiles, and wind power generation, and their scope of application has been further expanded due to their usefulness.

The substitute composite material carbon fiber reinforced plastic (CFRP) weighs in at around just 1/5 of aluminum-bronze. Despite its ultra-lightweight composition, CFRP exhibits the same or more strength compared to the aluminum-bronze composite materials used in conventional propellers. Due to its lightweight, CFRP propeller shafts can be manufactured with smaller diameters, reducing costs. In addition, by taking advantage of CFRP’s strength, it is possible to produce thinner propellers with smaller blade areas, potentially increasing the propeller’s efficiency.

In order to apply a composite propeller to ships, the material must have the required performance at least equal to existing aluminum-bronze composite materials, and it is necessary to confirm in advance that the composite propeller as an industrial product can be manufactured with uniform quality.

In May 2014, ClassNK granted approval for the design and manufacturing process of the CFRP propeller. The propeller was developed with support from the ClassNK Joint R&D for Industry Program and marked the world’s first installation of a CFRP propeller on a merchant vessel.

Based on the knowledge obtained through this joint R&D project, ClassNK comprehensively summarized the requirements for the approval of the manufacturing process for composite propellers and the testing/inspection of the product in the form of guidelines to assist in the effective use of composite material propellers on ships.

The Guidelines for Composite Propellers (Part on Manufacturing/Product Inspection) will be available on the ClassNK website for ClassNK “MyPage” users. Registration for ClassNK’s “MyPage” service is easy and free. Simply go to ClassNK’s website at and click on ‘My Page Login’.

For more information on this topic please contact

ClassNK Material and Equipment Department
Tel: +81-3-5226-2020

ClassNK - EOD