ClassNK: Survey and Construction of Ships of Fibreglass

The Nippon Kaiji Kyokai (ClassNK) amended its Rules for the Survey and Construction of Ships of Fibreglass Reinforced Plastics (FRP ships).

These amendments are in force from 1 January 2023.

These rules apply to FRP ships used for unrestricted service, except for oil tanks, that are less than 35 meters long and have a standard form.

For FRP ships used in restricted service, adjustments to hull construction, equipment, and measurements may be made based on service conditions.

The rules specifically pertain to FRP ships constructed through hand lay-up or spray lay-up methods, using fibreglass reinforcements and unsaturated polyester resins.

Ships that are primarily made of wood and simply covered with FRP or similar materials do not fall under the category of FRP ships.

In cases where FRP ships have unique shapes or proportions, are intended for specific cargo transportation, or are constructed using methods or materials not specified above, the hull construction, equipment, arrangement, and measurements will be determined at the discretion of the Society.

It should be noted that regardless of the aforementioned rules, FRP ships registered in Japan must also comply with the requirements outlined in other rules set by the Society.

The Society will consider alternative hull construction, equipment, arrangement, and measurements if they are deemed equivalent to the requirements stated in these rules.

For FRP ships that meet additional requirements or are exempted from certain criteria, an appropriate notation will be added to their Classification Characters, following the guidelines presented in Chapter 2 of the Regulation for the Classification and Registry of Ships.

The notation should be affixed similarly to 1.2, Part 1 of the Rules for High-Speed Craft, with the inclusion of the "FRP" notation indicating the use of fibreglass reinforced plastic as the main hull material specified in 1.2.3, Part 1 of the Rules for High-Speed Craft.