MARPOL 73/78 Annex VI Regulations for the prevention of Air Pollution from ships will enter into force on 19 May 2005,

Basically the code covers the following

Regulation 12 - Emissions from Ozone depleting substances from refrigerating plants and fire fighting equipment.

Regulation 13 - Nitrogen Oxide (NOx) emissions from diesel engines

Regulation 14 - Sulphur Oxide (SOx) emissions from ships

Regulation 15 - Volatile Organic compounds emissions from cargo oil tanks of oil tankers

Regulation 16 - Emissions from shipboard incinerators.

Regulation 18 - Fuel Oil quality.

and will apply to all ships of 400 gross tons and above which will have to carry an International Air Pollution Prevention Certificate (IAPP Certificate). This certificate must be on board at delivery for a ship constructed (keel laid) after 19 May 2005. For ships constructed before this date, the IAPP certificate must be on board at the first scheduled dry-docking after 19 May 2005, but not later than 19 May 2008. Ships constructed (keel-laid) before 1 January 2000 need to comply with operational requirements in MARPOL Annex VI from 19 May 2005. Unless existing engines are subject to major modification, or new engines or incinerators are fitted, the requirements in Regulation 13 and constructive requirements in Regulation 16 do not apply to vessels constructed before 1 January 2000.

Ships of less than 400 tons will still have to comply with the legislation where applicable, but in there case the Administration may establish appropriate measures in order to ensure that Annex VI is complied with.

Because this web site is concerned with marine diesel engines, regulations 13, 14 and 16 will be discussed in further depth.

NOx Emissions

This regulation applies to diesel engines with a power output of more than 130 kW each which are installed on a ship constructed on or after 1 January 2000; and each diesel engine with a power output of more than 130 kW which undergoes a major conversion on or after 1 January 2000. It does not apply to lifeboat engines or emergency generators.

All certified engines are delivered with an individual Technical File that contains the engine’s specifications for compliance with the NOx regulation, and the applicable onboard verification procedure. The certification process includes an emission test for compliance with the NOx requirements on the manufacturer’s test bed

There are three on board verification procedures which can be used The method used is initially decided by the engine manufacturer, and is usually a specific chapter in the engine’s Technical File.

• Engine parameter check method

• Simplified measurement method

• Direct measurement and monitoring method

The engine parameter check ensures that the present state of the engine corresponds to the specified components, calibration or parameter adjustment state at the time of initial certification. The engine’s Technical File identifies the components, settings and operating values that influences the exhaust emissions and these must be checked to ensure compliance during surveys and inspections. The components and settings will be those which affect the NOx produced by the engine, such as:

• Injection timing

• Injection system components (nozzle, injector, fuel pump)

• Injection pressure

• Camshaft components (fuel cam, inlet- and exhaust cam)

• Valve timing

• Combustion chamber (piston, cylinder head, cylinder liner)

• Compression ratio (connecting rod, piston rod, shim, gaskets)

• Turbocharger type and build (internal components)

• Charge air cooler/charge air pre-heater

• Auxiliary blower

• NOx reducing equipment

The  Simplified measurement method is where the NOx content of the exhaust gas is measured during  a 20 minute full load run of the engine. Due to the possible deviations when applying the simplified measurement method, an allowance of 10% of the applicable limit value is accepted for confirmation tests and during periodical and intermediate surveys.

For the direct measurement and monitoring method, the engine will be fitted with a direct measurement system which monitors the NOx emissions, either as spot checks logged regularly or continuous monitoring. Records must be kept for at least 3 months and must have been taken in the past 30 days.

SOx Emissions

Low and high sulphur fuel will have to be stored in different tanks. Different grades of cylinder oils may have to be carried if operating with low sulphur fuel for any length of time to prevent excessive calcium deposits and resultant wear. If low sulphur fuels are used, high wear rates may be experienced with fuel injection equipment.

Fuel Oil Quality

Although fuel oil quality is currently primarily a matter between owners/managers and suppliers, it will under Annex VI of MARPOL 73/78 also become a statutory matter. In addition to requirements limiting the sulphur content of oil fuel, Annex VI contains requirements preventing the incorporation of potentially harmful substances, and in particular waste streams (e.g. chemical waste), into fuel oils.

Bunker delivery notes must be kept on board for a minimum of three years and must contain the following information:

• Name and IMO number of receiving ship

• Bunkering Port

• Date of commencement of bunkering

• Name, address, and telephone number of marine fuel oil supplier

• Product name

• Quantity (metric tons)

• Density at 15°C (kg/m³)

• Sulphur content (% m/m)

A signed declaration from the the fuel oil supplier's representative that the fuel supplied has a sulphur level below 4.5% and that the fuel is free from inorganic acid and does not include any added substance or chemical waste which either jeopardises the safety of ships, adversely affects the performance of the machinery, is harmful to personnel, or contributes overall to additional air pollution is also required.

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