Prevention of air pollution from ships - MARPOL Annex VI & SEEMP guideline
Although air pollution from ships does not have the direct cause and effect associated with, for example, an oil spill incident, it causes a cumulative effect that contributes to the overall air quality problems. Eventually, it can hit a large section of the neighborhood population and also affects the natural environment, such as fierce acid rain. Therefore to prevent excessive air pollution from ships due to emission of smoke from the funnel must be correctly controlled and any local port regulations strictly adhered to.
Ships duty officers need to check periodically visual opacity of the funnel emissions and advise the engineer officer if it is of concern. Regular sighting of the funnel gases by the engineer officer will indicate whether combustion is efficient or not.
Modern vessels usually are fitted with a soot collection tank. The soot is discharged directly overboard via an eductor driven by the fire main or a similar arrangement. The soot disposal is to be logged in the garbage logbook – under category 6 – every time the soot is disposed of. It should include the position and time of disposal.
Prior to disposal the following items must be checked –
There is a dedicated tank for soot collection
The approved ship’s plan for this arrangement is available on board
In July 2011, IMO adopted a new chapter to MARPOL Annex VI that includes a package of mandatory technical and operational measures to reduce GHG emissions from international shipping. It aims to improve the energy efficiency for new ships through improved design and propulsion technologies and for all ships, both new and existing, primarily through improved operational practices. The measures came into force on January 1, 2013.
The measures aim to reduce carbon dioxide emissions by 100-180 million tonnes a year by 2020. All ships are now required to implement an energy-efficient management plan, including monitoring of fuel consumed. All-new ships built from 2013 and onwards will be required to meet a specific energy requirement (grams of CO2 per tonne-mile), which will be gradually tightened over time (every five years).
Funnel emission from a large container ship
The revised MARPOL Annex VI enforced on January 1, 2013.
The significant amendment to MARPOL Annex VI is the introduction of the new Chapter 4. The chapter provides regulations on energy efficiency for ships (SEEMP). The revised Annex also highlights North American Waters as Emission Control Areas (ECAs).
The impact of the Annex VI SOx controls will vary depending on whether a ship is operating in or outside an Emission Control Area. The North American ECA, which came into effect in August 2012, extends up to 200 miles offshore. It significantly increased the total global area covered by ECAs and the associated quantities of controlled fuel oils.
As for NOx ECAs, these will only affect ships constructed on or after January 1, 2016. Currently, the North American area will be the only NOx ECA.
We must expect that further Emission Control Areas – both for SOx or NOx – will be added over time. A US Caribbean ECA, covering both SOx and NOx emissions, is currently being considered by the IMO.
SEEMP was developed by a coalition of industry organizations through a working group on greenhouse (GHG) emissions convened by IMO MEPC and issued through circular MEPC.1/Circ. 684. SEEMP is a practical management tool that increases the energy efficiency of ships in operation through
improved voyage planning
speed and power optimisation
optimised ship handling
onboard energy management.
The measures consist of the requirement for an Energy Efficiency Design Index (EEDI) for new vessels and a Ship Energy Efficiency Management Plan (SEEMP) for new and existing vessels.
Revised MARPOL Annex VI
The main changes to MARPOL Annex VI are a progressive reduction globally in emissions of SOx, NOx, and particulate matter and the introduction of emission control areas (ECAs) to reduce emissions of those air pollutants further in designated sea areas. Under the revised MARPOL Annex VI, the global sulfur limit now reduced from earlier 3.50% to 0.50%, effective from January 1, 2020.
Further reading on control of air pollution requirement available in below IMO links:
ShipsBusiness.com is merely an informational site about various aspects of ships operation,maintenance procedure,
prevention of pollution and many safety guideline. The procedures explained here are only indicative,
not exhaustive in nature and one must always be guided by practices of good seamanship. User feedback is
important to update our database. For any comment or suggestions please Contact us Site Use and Privacy - Read our privacy policy and site use information. //Home //Terms and conditions of use
