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The adoption of MARPOL Annex VI has followed some years of debate within organisations. At the same time IMO Technical code on the Control of Emissions of Nitrogen Oxides from Marine Diesel Engines was adopted. MARPOL Annex VI and the Technical Code have retroactive requirements for diesel engines 130 KW and above installed on ships keel-laid on or after 1 January 2000, and Incinerators installed onboard on or after 1 January 2000.
MARPOL Annex VI will apply to all ships, fixed and floating drilling rigs and other platforms from 19 May 2005, but the certification requirements are depending on size of the vessel and time of periodical survey.
Ships of 400 gross tons and above engaged in international voyages involving countries that have ratified the conventions, or ships flying the flag of those countries, are required to have 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.
The IAPP certificate will be issued following an initial survey carried out by the Flag Administration or by a recognised organization (e.g. Det Norske Veritas) on behalf of the Flag Administration, confirming compliance with MARPOL Annex VI. For ships with the flag of an Administration that have not yet ratified Annex VI, a Certificate of Compliance with Annex VI may be issued by DNV.
Annex VI also requires diesel engines (as described above) to carry individual certificates with regard to NOx emissions, named Engine International Air Pollution Prevention (EIAPP) Certificates.
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Annex VI requires that every ship of 400 gross tonnage or above and every fixed and
floating drilling rig and other platforms shall be subject to the following surveys:
- An initial survey before the ship is put into service or before the IAPP Certificate is issued for the first time.
- Periodical surveys at intervals specified by the Administration, but not exceeding five years.
- A minimum of one intermediate survey during the period of validity of the certificate.
The Administration shall arrange for unscheduled inspections during the period of validity of the certificate. If the Administration establishes mandatory annual surveys, these unscheduled inspections shall not be obligatory, and for this purpose DNV has so far considered that all Administrations will apply a system with mandatory annual surveys.
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Annex VI has requirements to the following main issues, which will be highlighted
more in detail in this paper.
- 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.
Application for ships keel-laid before 1 January 2000
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. Formal certification of the ships applies at the first scheduled dry-docking after 19 May 2005.Regulation 12 Ozone depleting substances
Annex VI prohibits any deliberate emissions of ozone-depleting substances. Ozone-depleting substances, and equipment containing such substances, shall be delivered to appropriate reception facilities when removed from a ship.New installations which contain ozone-depleting substances are prohibited on all ships after the entry into force date, except that new installations containing hydrochlorflourocarbons (HCFCs) are permitted until 1 January 2020. The use of Halon in fire extinguishing systems and equipment is already prohibited for newbuildings. For newbuildings, this requirement in Annex VI will therefore always be complied with.
More restrictive requirements for ozone depleting substances are in place regionally, e.g. in the European Union (EU).
Regulation 13 Nitrogen Oxides (NOx)
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Regulation 13 of Annex VI concerns NOx-emission from diesel engines and shall
apply to:
- each diesel engine with a power output of more than 130 kW which is 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.
The phrase major conversion, means a modification of an engine where the engine is replaced by a new engine built on or after 1 January 2000, or any substantial modification is made to the engine, as described in the NOx
- Major Modifications
- changing camshaft, fuel injection system
- other NOx-related settings or components
- the maximum continuous rating of the engine is increased by more than 10%
- Substantial Modification is defined as follows
- For engines installed on vessels constructed on or after 1 January 2000, a Substantial Modification means any modification to an engine that could potentially cause the engine to exceed the emission standards set out in Regulation 13 of Annex VI. Routine replacement of engine components by parts specified in the Technical File that do not alter emission characteristics shall not be considered a Substantial Modification, regardless of whether one part or many parts are replaced.
- For engines installed on vessels constructed before 1 January 2000, a Substantial Modification means any modification made to an engine which increases its existing emission characteristics established by the simplified measurement method in excess of the allowances set
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According to Annex VI the operation of applicable diesel engines are prohibited
except when the emission of nitrogen oxides from the engine is within the following
limits:
- 17,0 g/kWh when n is less than 130 rpm
- 45,0 з n(-0,2) g/kWh when n is 130 or more but less than 2000 rpm
- 9,8 g/kWh when n is 2000 rpm or more
Certification and onboard verification
The EIAPP (Engine International Air Pollution Prevention) certificate is required for all diesel engines as described above, and will be issued for marine diesel engines after demonstrating compliance with NOx emission limits. The certification process is to be carried out in accordance with the NOx Technical Code issued by IMO.-
The following engines require EIAPP Certificates:
- Engine power output above 130 kW
- Is the vessel constructed (keel laid) before or after 1 January 2000?
- Major conversion of the engine on or after 1 January 2000?
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The NOx Technical Code opens for 3 different onboard verification procedures:
- Engine parameter check method
- Simplified measurement method
- Direct measurement and monitoring method
Methods of Checking Compliance
Engine parameter check method Rather than having to measure the actual level of NOx it is acceptable that a record be kept to ensure the current status of the engine is equivalent to that when NOx readings were taken initially. 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.-
To satisfy the requirements of this method the following must be available:
- Technical File including the onboard verification procedure.
- Record book of engine parameters for recording all of the changes made relative to an engine�s components and settings. Also to include technical documentation in case of modification of any of the engine�s designated components.
- EIAPP certificate (Statement of Compliance) for each applicable engine.
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The NOx-influencing components and settings depend on the design of the particular
engine, and shall be listed in the engine�s Technical File. The below list shows typical
NOx-influencing parameters:
- 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 'water injection'
- NOx reducing equipment 'emulsified fuel' (fuel/water emulsion)
- NOx reducing equipment 'exhaust gas recirculation'
- NOx reducing equipment 'selective catalytic reduction'
There may be situations where the engine maker comes up with a new design for one of the NOx-influencing components, with a different Id No from what�s stated in the Technical File. The new design should then be approved by the Administration (or DNV on behalf of a Flag Administration when authorised) and the change is to be documented in the 'Record book of engine parameters'. The same is applicable for all other changes the engine may be approved for during its lifetime.
Simplified measurement method
This involves full load running of the engine for about 20 minutes, and will in most cases require a test trial.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.
Direct measurement and monitoring method
The ship-owner will have the option of direct measurement of the NOx emissions
during the engine operation. Such data can either take the form of spot checks
logged with other engine operating data on a regular basis and over the full range of
engine operation, or they can result from continuous monitoring and date storage.
Data must be taken within the last 30 days, and must have been acquired using the
test procedures given in the NOx Technical Code. These monitoring records are to
be kept onboard for at least three months for verification purposes. To demonstrate the compliance by the direct measurement method, sufficient data shall be collected to calculate the weighed average NOx emissions in accordance with the NOx Technical Code.
It should be noted that the two methods that involve measuring of the exhaust emissions do not include any kind of identification markings of the NOx-influencing components.
Surveys and inspections
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Following the regime of the IAPP certificate, the diesel engines will also be subject for
the following surveys:
- An initial survey before the ship is put into service or before the IAPP Certificate is issued for the first time.
- Periodical surveys at intervals specified by the Administration, but not exceeding five years,
- A minimum of one intermediate survey during the period of validity of the certificate.
- Annual Surveys (or a Flag Administration may instead implement
unscheduled inspections as an alternative to Annual surveys)
If the 'Engine Parameter Check Method' is the selected onboard verification procedure, the surveyor will typically want to see:- EIAPP Certificates for all applicable diesel engines onboard
- Approved Technical Files including �Onboard verification procedure� for all the applicable diesel engines onboard
- Record Book of Engine parameters for all the applicable diesel engines onboard
- One or all of the identified components, settings or operating values specified in the engines� Technical File
- EIAPP Certificates for all applicable diesel engines onboard
- Approved Technical Files including �Onboard verification procedure� for all the applicable diesel engines onboard
- All recommendations from engine manufacturer and approvals from the Administration concerning the 'Simplified Measurement Method'
- Test results
- EIAPP Certificates for all applicable diesel engines onboard
- Approved Technical Files including 'Onboard verification procedure' for all the applicable diesel engines onboard
- Documentation/Approval of the installed measuring equipment
- Logged measurement results in order to verify that the engines comply with the NOx Technical Code.
Engines with EIAPP certificates issued by another company
Although there are several companies able to certify engines only those approved by flag State will be acceptable to the administration (generally Class) who have been authorised to issue certification.Regulation 14 - Sulphur Oxides (SOx)
General
Upon entry into force of Annex VI to MARPOL on the 19 May 2005, the sulphur oxide (SOx) emissions from ships will be controlled by setting a limit of 4.5% on the sulphur content of marine fuel oils. Further, a limit of 1.5% on the sulphur content of marine fuel oil will apply in designated SOx Emission Control Areas (SECAs). IMO has currently agreed on the designation of two SECA�s as per below. The first designated SECA is the Baltic Sea Area which has been agreed that will enter into force on the 19 May 2006. The second area, the North Sea Area and the English Channel has also been agreed, but due to the amendment process in IMO, it has been indicated that it will not enter into force as a SECA until 19 November 2007. It is expected that further SECA�s will be designated in the future and IMO has set forth certain criteria for designating such SECA�s.The limitations in sulphur content applies to all fuel oils (heavy fuel oils, marine diesel oils and gas oils) and regardless of use on board (i.e. in combustion engines, boilers, gas turbines etc.).
Currently, the average sulphur content in fuel oils is in the region of 2.7% with only 0.2% having Sulphur content above 4.5%. However only 4% of fuels have less than 1.5%.
Exhaust Gas Cleaning systems
As an alternative to using marine fuel oil with a 1.5% sulphur content in SECA�s, an exhaust gas cleaning system or other equivalent system may be used (abatement technologies). The emission criteria for such systems are 6 g SOx/kWh.Development of a type approval standard for such systems is ongoing in IMO. The current available abatement technology is based on seawater scrubbing principles.
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There is however a few concerns related to these types of scrubber type systems:
- Annex VI states that port states may prohibit discharge of scrubber effluent overboard in ports within SECA�s unless it can be documented that the effluent complies with criteria set by that port state. A mitigating measure is installation of filtration/treatment systems.
- It has been indicated that conventional scrubber technology may be struggling to meet the emission criteria at high exhaust gas discharge flows.
- It has been indicated that there is a risk of blue-sheen originating from the scrubber overboard discharge. Although, not necessarily constituting an environmental hazard, the mere risk of such occurrences is to some operators unacceptable.
- There are space considerations in the engine room and more specifically the funnel. Although it has been indicated that the more advanced scrubber types can replace standard silencers, the associated piping systems may represent a challenge. Pressure drop in scrubbers has also been indicated as a limitation, particular in way of main engines uptakes.
- Tanker owners have had mixed experiences with corrosion of inert gas scrubbers and associated piping systems.
- The EU has been reluctant to accept scrubbers. Based on trials they have indicated that they may accept abatement technology as an equivalent to low sulphur fuel. Note that EU has indicated that it will develop criteria for resulting waste streams in their ports.
EU Directive 1999/32/EC with proposed amendments
In connection with MARPOL Annex VI one cannot disregard ongoing low-sulphur developments in the EU.-
EU directive 1999/32/EC has been amended a number of times, and in force today is
the following:
- Member states to ensure that Marine Distillates used within their territory from July 2000 do not exceed 0,2% Sulphur (0,1 % from January 2008). In other words, ships must ensure that if they are using Marine Distillates in EU territory (territorial waters including seas 12 nautical miles from shore and inland waterways), their sulphur content is below 0,2%. Marine Distillates in this context include both marine gas oils and marine diesel oils (DMX, DMA, DMB and DMC). As far as DNVPS has been informed this requirement is currently only enforced by Dutch Authorities Amendment to EU directive 1999/32/EC reached a common position in July 2004, and although the amendment process is in its final stages, implementation date is highly uncertain and further amendments cannot be ruled out. As of July 2004 the following is in the pipeline:
- A 1.5% sulphur limit for fuels used by all ships in the Baltic Sea, North Sea & Channel in accordance with the implementation dates of Annex VI to MARPOL (i.e. starting in 19 May 2006 for the Baltic Sea Area). As of 19 May 2006, EU member states shall ensure that the sulphur content in marine diesel oils (ISO 8217 grades DMB and DMC) supplied within their territory does not exceed 1.5%.
- A 1.5% sulphur limit for fuels used by passenger vessels on regular services between EU ports as of 19 May 2006.
- A 0.1% sulphur limit on fuel used by inland vessels and by seagoing ships at berth in EU ports. The Council agreed this limit delayed until 1 January 2010, to allow single-fuel ships time to adapt their fuel tanks.
- A further two year delay has been proposed given to 16 unifuel (vessels using heavy fuel oil for both main and auxiliary engines) ferries serving the Greek islands.
- As of 1 January 2010, EU member states shall ensure that the sulphur content in marine gas oils (ISO 8217 grades DMX and DMA) supplied within their territory does not exceed 0.1%.
- For ships arriving from outside the EU, the requirement need only be complied with upon leaving the EU port of call.
Low sulphur heavy fuel
It has been indicated that experience in terms of low sulphur residual (or heavy) fuel oil blending is varying and that quality problems are to be expected. Although there is limited usage of (blended) low sulphur fuel oils, DNV Petroleum Services has already seen indications that the low sulphur processing of fuel oils may lead to additional quality problems such as instability, incompatibility, ignition and combustion difficulties and an increase of catalytic fines levels. Regrettably one has also seen cases where chemical waste has been introduced in such fuel.Fuel tank/system configuration
It should be noted that when approaching a SECA the fuel must be changed over to the 1.5% sulphur content fuel and completed before entering the SECA. That is all the fuel lines to the engine must have this fuel only.-
There are two approaches to this
- FLushing - low sulphure fuel is used to flush out the higher sulphur fules from the settling/service tank
- Duplication of tanks- seperate Settling/service tanks are installed for the two types of fuels. This has the potential to simplify the change over proceedure and reduce risk of fuel imcompatibilities.
The differences in cost between low and high sulphur heavy fuel oils as well as between heavy fuel oils and low sulphur diesel oils, has led some owners to consider separating fuel treatment and service piping systems. This is increasingly important with respect to potential requirements to use of ultra low sulphur fuels in EU ports
In order to facilitate safe and simple change-over, the installation of separate marine gas oil/diesel oil supply piping with heating capabilities should be considered. (While separate direct diesel oil supply lines are often arranged for auxiliary diesel engines, the same is less frequently encountered for boilers and main engines.)
The below serves as examples of proposed modifications regarding duplicated heavy fuel oil service and settling tanks and piping systems.
Change-over procedures
The time, ship�s positions at the start and completion of change-over to and from 1.5% fuel oil must be recorded in a logbook (e.g. ER log. book), together with details of the tanks involved and fuel used. It can be anticipated that the same will be applicable with respect to the EU proposal upon entry into force.Regulation 15 � Volatile Organic Compounds
Emissions of volatile organic compounds (VOCs) from tankers may by each party to Annex VI be regulated in its ports and terminals. Such requirements shall be given in a list published by IMO. The list shall also specify size of tankers, and which cargoes, that requires vapour emission control system. All tankers which are subject to vapour emission control in accordance with above list shall be provided with an approved vapour collection system, and shall use such system during the loading of such cargoes.Existing tankers which are not fitted with vapour collection systems may be accepted for a period of three years after the terminal was included in the above list. DNV has for many years had class notations VCS 1 and 2 for vapour control systems complying with IMO Guidelines (MSC/Circ.585), and USCG regulations. It may be noted that a vessel complying with VCS- 1 or 2 will comply with regulation 15. This regulation shall only apply to gas carriers when the type of loading and containment systems allow safe retention of non-methane VOCs on board, or their safe return ashore.
Regulation 16 � Shipboard Incineration
Onboard incineration outside an incinerator is prohibited except that sewage sludge and sludge oil from oil separators may be incinerated in auxiliary power plants and boilers when the ship is not in ports, harbours and estuaries. Incineration of Annex I, II and III cargo residues, of PCB's (Polychlorinated biphenyls), of garbage containing more than traces of heavy metals and of refined petroleum products containing halogen compounds is always prohibited.Incineration of PVC�s (polyvinyl chlorides) is prohibited except in shipboard incinerators type approved according to resolutions MEPC 59(33) or MEPC 76(40).
Monitoring of combustion flue gas outlet temperature shall be required at all times and waste shall not be fed into a continuous-feed shipboard incinerator when the temperature is below the minimum allowed temperature of 850АC. For batch-loaded shipboard incinerators, the unit shall be designed so that the temperature in the combustion chamber shall reach 600АC within 5 minutes after start-up. It must be ensured that the incinerators' flue gas outlet temperature monitoring system is operational.
All incinerators installed on or after 1 January 2000 shall be type approved in accordance with Resolution MEPC 76(40) giving the IMO standard specification for shipboard incinerators. For such incinerators a manufacturer's operating manual is required.
Regulation 18 � Fuel Oil Quality
General While fuel oil quality is currently primarily a matter between owners/managers (and charterers) 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.Regulation 18 specifically requires that fuel oil supplied to ships is to be free from inorganic acids or chemical wastes that could jeopardise the safety of the ship, be harmful to ships' personnel, or which would contribute overall to additional air pollution. The addition of small amounts of additives intended to improve performance is however permitted.
Incidentally, the requirements to fuel oil quality in Regulation 18 are more or less identical to the general requirements of ISO 8217, although no references are made to the same. Accordingly one question raised has been whether a fuel found off-spec compared to ISO 8217 test parameters is in violation of Regulation 18. Consultations with certain port states indicate that this will likely not be the case. Instead it has been indicated that Regulation 18 may be enforced in case a ship is involved in accidents or near-accidents where fuel quality is a suspected contributor.
Operational issues
It is important to note that elaboration and clarifications relating to Regulation 18 are found in Resolution MEPC. 96(47) 'Guidelines for the sampling of fuel for determination of compliance with Annex VI of MARPOL 73/78'. Although this is a guideline, it is expected that the guideline will be used as requirements by port state inspectors. It should be noted that Intertanko has issued a thorough and useful guideline related to Annex VI which elaborates on the issues at hand.Bunker delivery notes
It is a requirement of Regulation 18 that any fuel oil for combustion purposes delivered to and used onboard shall be recorded by means of a Bunker Delivery Note (BDN). This implies that a bunker delivery note shall be presented for every barge delivery and every grade.-
Bunker Delivery Notes are required to contain all specific information as follows:
- 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 oC (kg/m3)
- Sulphur content (% m/m)
- A declaration signed and certified by the fuel oil supplier's representative that the fuel oil supplied is in conformity with regulation 14 and 18 (I.e. that the fuel supplied has a sulphur level below 4.5% and that the fuel is free from inorganic acid, 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).
- Resolution MEPC.96(47) recommends that the seal number of the associated MARPOL Annex VI fuel sample is included in the BDN's for crossreference purposes.
MARPOL 73/78 Annex VI fuel oil samples
Regulation 18 requires that every BDN is to be accompanied by a representative sample of the fuel oil delivered, taking into account the guidelines in Resolution MEPC.96(47). The sample is to be sealed and signed by the supplier's representative and the master or officer in charge of the bunker operation on completion of bunkering operations, and retained under the ship's control until the fuel oil is substantially consumed, but in any case for a period of not less than 12 months from the time of delivery. Although MEPC.96(47) specifies that the volume of the sample bottle should be no less than 400 ml, due to potential need for repetitive testing, Intertanko has recommended that the sample volume is not to be less than 750 ml.For the sake of good order it should be noted that the practical purpose of this sample is to enable port states to verify the sulphur content of the fuel, as well as to verify that the fuel oil quality is in accordance with Regulation 18.
As Annex VI specifies that the Annex VI sample is not to be used for commercial purposes, DNV Petroleum Services recommends that for ship�s already participating in a fuel oil quality testing scheme, the Annex VI sample should be the fourth sample (in addition to the sample sent to laboratory for testing, suppliers sample and the retained onboard sample). The reason is that it is considered an advantage to always have an Annex VI sample onboard in case of port state controls.
Sampling procedures
Note that the referred to Resolution MEPC.96(47) specifies in detail that the fuel sample is to be obtained at the receiving ship�s inlet bunker manifold and is to be drawn continuously throughout the bunker delivery period. The term continuously drawn is specified to mean a continuous collection of drip sample throughout the delivery of bunker fuel. Sampling methods are further clarified as either; manual valve-setting continuous-drip sampler (equivalent to DNV Petroleum Services� Line sampler), time-proportional automatic sampler, or flow-proportional automatic sampler.-
Further the guidelines specify that sample bottle labels are to contain the following
information:
- Location at which, and the method by which, the sample was drawn
- Bunkering date
- Name of bunker tanker/bunker installation
- Name and IMO number of the receiving ship
- Signatures and names of the supplier�s representative and the ship's representative
- Details of seal identification
- Bunker grade.
Sample inventory
Resolution MEPC.96(47) also contains recommendations on sample storage location.Supplier�s responsibility
While most IMO conventions place full responsibility on the ships and ship owners, Regulation 18 places a certain responsibility on the suppliers (fuel oil quality declaration, BDN and the Annex VI fuel oil sample by continuous drip and at the receiving ships manifold).-
Annex VI of MARPOL also contains instruments to encourage port states to ensure
that suppliers fulfil their obligations. Port states are therefore required to:
- Maintain a register of local suppliers of fuel oil;
- Require local suppliers to provide the BDN and sample, certified by the fuel oil supplier that the fuel oil meets the requirements of regulations 14 and 18.
- Require local suppliers to retain a copy of the bunker delivery note for at least three years for inspection and verification by the Port State as necessary;
- Take action as appropriate against fuel oil suppliers that have been found to deliver fuel oil that does not comply with that stated on the Bunker Delivery Note;
- Inform the Flag Administration of any ship receiving fuel oil found to be noncompliant with the requirements of regulations 14 or 18 of this Annex.
- Inform IMO for transmission to Parties to the Protocol of 1997 of all cases where fuel oil suppliers have failed to meet the requirements specified in regulations 14 or 18.
Third party inspections
It can be expected that upon implementation, class surveyors, port state inspectors and possibly also vetting inspectors will scrutinise onboard documentation and records (e.g. sampling procedures, change-over procedures, ER log books, BDN's, sample inventory log books etc.), as well as the fuel oil sample inventory.The updated list showing state of ratification can be found on IMO's web pages (www.imo.org/home.asp) under 'conventions' and 'status of conventions by country. For further information, please contact: Annex VI in general: DNV, Cargo Handling, Piping Systems, Marpol and Gas Carriers (MTPNO880@dnv.com) NOx and engine related inquir
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