Mandatory Code on Nox Emissions - Engine Certification

Each engine is to be certified and issued with an Engine International Air Pollution Prevention (EIAPP) Certificate relative to NOX emissions. In certain instances (parent engines of an engine family or engine group, or engines that are not manufactured under the family or group concept) require a pre-certification survey to ensure compliance with the NOX emission limits.

The family concept is for any series of engines which by design are shown to have similar emission characteristics, whereas the group concept normally applies to large main propulsion engines which may require only minor adjustments during installation on board.

Prior to issuance of the EIAPP Certificate and after an engine is installed on board and adjusted/modified from the pre-certification survey, an initial survey is to be carried out. Periodic (annual and intermediate) surveys, conducted with the surveys required for the IAPP Certificate, are also required.

Initial and periodic verifications may be accomplished by (1) applying a simplified measurement technique which allows for greater deviations of measurements and partial use of the test bed data; or (2) verifying that the engine’s components, settings and operating values are within the manufacturer’s specifications. A third option (3) involving the directly monitoring the exhaust gases may be applied only for periodic verifications.

Engines which have been substantially modified are subject to an initial verification.

The manufacturer’s specifications, together with the test bed report and performance data must be contained in the engine’s Technical File which is to be readily available on board the ship. Details regarding test measurement methods and tolerances, analysis procedures and sampling requirements are detailed in the mandatory NOX Code.