Australian Maritime Safety Authority (AMSA) issued a marine notice, in order to provide general information to shipowners, masters and crews on Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL). Annex VI of MARPOL contains regulations for the prevention of air pollution from ships.
This Marine Notice focuses on MARPOL Annex VI regulations, that control emissions of sulphur oxides (SOx) and particulate matter, and nitrogen oxides (NOx). These controls are divided between those applicable inside IMO designated Emission Control Areas (ECAs) and those applicable elsewhere.
SOx and Particulate Matter Emissions
SOx and particulate matter emissions are a function of the sulphur content of fuel. The SOx control requirements in MARPOL Annex VI provide for a progressive global reduction in the sulphur content of fuel oil to reduce the emission of SOx and particulate matter from ships.
The current maximum sulphur content of fuel oil for ships operating in areas other than ECAs is 3.5% m/m (mass/mass). This limit will be reduced to 0.5% m/m from 1 January 2020. This reduction follows an International Maritime Organization (IMO) commissioned study1 to review the global and
regional demand for, and supply of, fuel oil complying with the 0.5% m/m limit.
The maximum sulphur content of fuel oil for ships operating in ECAs is 0.1% m/m. Four SOx ECAs have been designated by the IMO. These are the Baltic Sea, North Sea, the North American area (both east and west coasts of the United States and Canada) and the United States Caribbean Sea area.
MARPOL Annex VI provides provisions for when a ship, despite best efforts, cannot purchase compliant fuel oil during its planned voyage. In this case, the ships’ owners and operators must notify their Administration (for Australian vessels, AMSA) and the competent authority of the relevant port of destination prior to arrival in the port. In Australia, local fuel oil suppliers are required to be registered with AMSA.
NOx Regulations for Marine Diesel Engines
Regulations in MARPOL Annex VI provide for progressive reductions in NOx emissions from marine diesel engines, with a power output of more than 130 kW, installed on a ship. NOx emissions are restricted to certain limits (Tier I, II and III) based on the ship’s construction date; date of major conversion and area of operation. Within each of these Tiers, the NOx emission limit is set based on the ship’s rated engine speed (crankshaft rpm).
The Tier I and II limits apply to marine diesel engines installed on ships constructed, or undergoing a major conversion, on or after 1 January 2000 and 1 January 2011 respectively. Replacement engines and additional engines installed on existing ships are required to meet Tier II standards, unless they meet the defined criteria for an ‘identical engine’.
These limits apply in all areas not designated as a NOx ECA. The more stringent Tier III limits apply to marine diesel engines installed on ships constructed on or after 1 January 2016 operating in existing NOx ECAs. Replacement engines, installed on existing ships operating in NOx ECAs, are required to meet Tier III standards where possible. Additional engines must meet the Tier III standard.
There are currently two NOx ECAs – the North American area and the United States Caribbean Sea area. For additional NOx ECAs designated in the future, Tier III controls will apply to ships constructed on or after the date of the adoption of such an ECA, or a later date as may be specified in the designation of the ECA, when operating in the area.
NOx Standards for Existing Engines
Existing marine diesel engines with a power output of more than 5,000 kW, and a per cylinder displacement at or above 90 litres, installed on a ship constructed on or after 1 January 1990 but prior to 1 January 2000, are also required to comply with Tier I limits.
To achieve compliance, such existing marine diesel engines must also have an Approved Method (for example, an engine upgrade kit) certified by an Administration, and the IMO needs to be notified. When an Approved Method has been certified, it is to be applied to all relevant engines on ships no later than the first renewal survey that occurs 12 months or more after IMO is notified. A publicly available list of Approved Methods and notification dates is maintained online in the IMO Global Integrated Shipping Information System (GISIS).
Where the owner or operator of an Australian ship is able to demonstrate to AMSA that an Approved Method is not commercially available, the above requirement may be extended, so that it is installed on the ship, no later than the next annual survey which falls after the Approved Method is commercially available.
Further information may be found in the following report:
Source: AMSA
