Classification Services


As a leading international classification society,

ClassNK is well regarded as a highly reliable, trustworthy and impartial third party organization by marine transport, shipbuilding, and other maritime related industries around the world.

Importantly, classification and registration of a ship by the Society ensures the ship is recognized by underwriters the world over, including the Institute of London Underwriters.

Survey and Registration for Classification of Ships and Installations:

Before a ship or offshore structure can be registered, it must be surveyed in accordance with technical Rules and regulations of the Society. Once the ship has been surveyed to the satisfaction of the surveyor, classification of the ship is reviewed by the Classification Committee of the Society. If approved, a certificate of classification or installation registration, as appropriate, is issued and the ship is entered into ClassNK's Register of Ships.

Surveys for Maintenance of Class:

Ships and offshore structures together with installations that have been classed and registered with the Society undergo periodic and occasional surveys to ensure that they continue to satisfy ClassNK technical Rules and the requirements of class.

Ship Classification Related Services

  • Survey and registration of ships and offshore structures during construction
  • Survey and registration of ship installations, machinery and appliances
  • Survey and inspection of ships, offshore structures and related installations in service for the maintenance of class
  • Inspection and type approval of materials, equipment and similar products
  • Approval of service providers, manufacturers and manufacturing methods
  • Testing and inspection of materials and various types of testing machines

ClassNK performs drawing examinations,approvals, and ship surveys as part of its services for registering and maintaining ships in class. In order that these activities may be carried out more effectively, the Society also conducts various other approval and inspection services as described below.

Approval of Materials, Machinery and Equipment:

ClassNK offers approval services for the following materials, machinery and equipment;

Steel plates, steel pipes, as well as non-ferrous and other materials,
Welding materials,
Fire protection materials, insulating materials, and oil-impervious materials,
Engine room machinery and equipment,electrical and automatic machinery,
Ventilating systems and equipment for the prevention of marine pollution,
Anchors, chains, rope, and other types of equipment and gear for ship use,
Equipment and devices used in life saving appliances, fire extinguishing systems and other types of arrangements.

In order to rationalize the conduct of classification surveys as well as assure and enhance the quality of ships under class, ClassNK conducts assessments of the quality systems, production processes, and facilities of manufacturers based on various technical Rules for the purpose of approving the production, maintenance and repair of materials, equipment and other components used onboard ships classed with the Society. Manufacturers whose quality systems and actual production practices have been thus approved may have certain aspects of surveys of these materials and equipment simplified.

The Society also carries out inspections and approvals of companies who provide testing and measurement services that are used in the survey and registration of ships and machinery as well as the maintenance of class. These include inspecting the quality system of the companies, the education, training and qualification of technical staff and other personnel engaged in providing the service, as well as inspecting the testing and measurement instruments and equipment used in the course of providing the service. Companies found to satisfactorily meet the requirements for providing a given service are approved as recognized service providers with respect to the conduct of related surveys of ships and equipment.

At present, the Society conducts the following types of inspections and approvals for service providers;

  • In-water surveys
  • Plate thickness measurements
  • Radio communication inspections
  • Maintenance of fire fighting equipment
  • Maintenance of life-saving appliances
  • Performance testing of voyage data recorders
  • Tightness testing of hatches using ultrasonic equipment

Natural Resources and Energy Department


A new department, the Natural Resources and Energy Department, was set up on 1 October 2011 as part of the Society’s diversification into the promising offshore sector of the energy industry. This department takes on the role of the now defunct tanker section of the Hull Department.
The services offered by this department build upon the Society’s vast array of expertise to offer high quality support tailored to the needs of clients in the oil, chemical and gas sectors.
The scope of the department’s activities covers the entire process, from upstream projects such as extraction via Floating Production, Storage and Offloading Systems (FPSO) through to activities further downstream including the transportation by ship of the extracted oil or gas. This position allows ClassNK to be at the forefront when it comes to developing new technologies and service solutions for the industry as such needs arise.

Key Services offered by the Department

  • Plan approval for newly built oil tankers, chemical tankers, and gas carriers
  • Certification for tanker-related conventions including MARPOL, IBC Code, and the IGC Code
  • Certification services for the loading of chemical cargo
  • Plan approval for the conversion of oil tankers, chemical tankers, and gas carriers in service
  • Concept Approval for new designs of liquefied natural gas (LNG) cargo tanks and LNG fuel tanks
  • Plan approval for floating offshore facilities (FPSO/FSO) for the production and storage of oil
  • Plan approval for floating offshore facilities (LNG-FPSO) for the production, storage, and offloading of LNG
  • Plan approval for the structure and moorings of floating wind turbines
  • Plan approval for ultra large floating structures
  • Comprehensive provision of technical development and services