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High anxiety in the shipping industry about "Low Sulphur Fuel"

With just several months left before the IMO Marpol 73/78 Annex VI comes into force in 2005, many ship owners and ship operators are still grappling with the technical implications of the fuel sulphur regulations.


The key question is whether commercial vessels with their existing engine and tank configurations are prepared to consume bunkers with lower sulphur content, particularly when they enter the so-called Sulphur Emission Control Areas (SECAs).

Ship owners and ship operators should first be aware of the differences between heavy fuel oils (HFO) and ‘distillates’ such as marine diesel oils (MDO) and marine gas oils (MGO).


Unlike distillate fuels, HFO requires heating before being injected into diesel engines or boilers, due of their high viscosities.

The latest statistics indicate that world average sulphur levels in residual fuels is about 2.6%, but in some areas, fuels with a sulphur content of up to 4.5% are common. Such fuels may be termed high sulphur fuels (HSF). Most engine manufacturers and lube oil suppliers describe low sulphur fuels (LSF) as products containing less than 1% sulphur, although some may include sulphur levels of up to 1.5%.


ISO 8217 specifications currently limit sulphur content to 1.5% for MGO and 2% for MDO as well as blended diesel oils, while  statistics suggest that actual average sulphur content for all distillate fuels is about 0.6%.

The EU directive, however, is proposing that ships at berth in some areas consume LSF with a maximum of 0.2% sulphur. From 2008, this limit may be lowered to 0,1%.


In the absence of an international definition for marine fuels with 0.2% sulphur or less, we will call such fuels Ultra Low Sulphur Fuels (ULSF).

The bunker industry, presently, has little or no knowledge about the characteristics of LSF and ULSF, both of which are not yet readily available in the market place. This could be a major problem for marine fuel refiners as they will soon face mounting pressure to meet the increased demand for low sulphur products, presumably by introducing new production processes.


‘Single-Fuel’ ships, designed to operate all their marine engines on HFO, will also face numerous technical challenges when consuming LSF and ULSF; especially during the change-over from HFO to LSF or ULSF and vice versa.

To begin with, HFO and fuels with low sulphur content may be incompatible in certain blending ratios. During the change-over from HSF to LSF/ULSF, and vice versa, distillate components may disturb the stability of the HFO and cause asphaltenic sludge to precipitate. In the worst cases, the engine hot filters will be choked, causing fuel starvation and other ill consequences for the ship.


LSF and ULSF used in combination with cylinder lubricating oils with high Base Number (BN) may also result in over-lubrication, leading to cylinder liner lacquering and scuffing. On the other hand, some ULSF do not provide sufficient lubricity to high-pressure fuel pumps for problem-free operation. Those high in aromaticity often have poor ignition and combustion properties, possibly due to the de-sulphurising processes in the refineries having a negative impact on the properties of the fuels' blended components.


Last but not least, the existing tank capacity and pipelines designs on many ships make segregation of HSF and LSF difficult or even impossible.

While two-stroke marine diesel engines may be able to consume LSF for short periods, long-term LSF operation can be problematic and thus raise safety concerns, particularly when the vessels are sailing in congested waters or in the SECAs.


To what extent two-stroke main engines will have to consume ULSF remains to be seen, since the regulations are still unclear about the restrictions in SECAs and inland waterways in the EU. Most likely, the consumption of ULSF ‘at berth’ as mentioned in the regulations should imply mainly the use of auxiliary engines to power winches, cargo pumps and cranes.


So how to prepare for the low sulphur regulations ?

The IMO and EU regulations are unfortunately not in line with each other on how SOx emissions can be reduced. As an alternative to burning low sulphur fuels, the IMO permits the use of approved after-treatment exhaust gas cleaning systems or other technologies that can be verified to limit SOx emissions.


The EU directive, in its present edition, is less flexible and only allows fuels with maximum 1.5% sulphur to be used in restricted areas.

Hence, if exhaust gas cleaning is not going to be a viable alternative in the EU, ship operators must equip their vessels with more segregated units of bunker tanks, settling tanks, service tanks and cylinder lubricant tanks. Tank layout and design should ideally be planned during the new building process since modifications on existing installations can be costly. Even so, ships have this option to reconfigure their onboard fuel treatment plants.


For the vessel’s chief engineer, the best way to detect possible problems is to frequently check the condition of the main engine piston crown and to inspect the piston ring pack through the scavenge air ports. Over-lubrication should generally be avoided, but in practice, this may not be a safe practice because engine tolerances are small.


Moreover, when ships according to the proposed EU regulations consume LSF in the SECAs, they could be sailing in narrow straits, channels and passages, where engine failure is potentially disastrous. In this regard, two-stroke engines should preferably use a cylinder lubricant with reduced BN. During prolonged LSF operation or if ULSF consumption is unavoidable, the chief engineer should seek relevant advice from the vessel’s engine builder and the lubricant supplier.


Fuel testing companies(FOBAS) can also help ships cope with low sulphur fuels.

As the Marpol Annex VI regulations will be in force as of May 19th 2005 large ship operators preparing their vessels for low sulphur fuel consumption will have to make many important decisions quickly.

Among the considerations, they will have to assess the necessary modification to current tank arrangements for segregating HSF from LSF.

Ship operators should also know which type of low TBN cylinder oil is most suitable for their vessels’ LSF and ULSF operation. They will need to source for reliable suppliers of low TBN cylinder oils and determine whether adequate amounts of these products can be kept on board to replace high BN cylinder oil when required.


High sulphur content fuels require cylinder oils with a high TBN (Total Base Number). High sulphur fuels generate sulphur oxides during the combustion process which when combined with water, also formed during combustion, can cause corrosive sulphuric acid. The alkaline additives in high TBN cylinder oils neutralize the corrosive acids generated during the combustion process. Accordingly, low sulphur fuels would need a cylinder oil with a lower TBN.

Typically your low sulphur fuel oils are gas oils or diesel oils which are "lighter" oils with lower viscosities and consequently lower lubricating qualities when compared to heavy fuel oil (HFO). All slow and most medium speed disel engines are designed to operate on HFO. If running-in an engine on a lighter fuel, more time would be required to wear in the cylinder liner and piston rings.


Finally, ship owners and ship operators must ensure that their chief engineers are comfortable with the change-over procedures for distillate fuel operation, and that the ship crews can monitor cylinder liner condition effectively.




What the regulations say

-Marpol Annex VI-  IMO Assembly Resolution A.719(17)

From May 19th 2005 all sea going vessels above 400 GT are required to take samples during bunkering operations, this in conjunction with Air Pollution Marpol Annex VI. The samples are to be stored on board the vessel for a period of 1 year. Vessels trading in SOx Emmision Control Areas (SECAs) will be required to produce an "International Air Pollution Prevention Certicicate". The Baltic Sea will fall under a SEC Area. Other SECAs will follow in the future.


Requirements for control of emmisions from ships; Link IMO


Ozone depleting substances

Prohibited ..... except new

installations containing HCFCs (Hydrochlorofluorocarbons) are permitted until January 1st 2020

Nitrogen oxides

Each diesel engine with an output power of 130KW which is installed on a ship constructed  on or after January 1st 2000

Sulphur Oxides

Sulphur content of any fuel oil used on board ships shall not exceed 4,5% m/m, in SEC Areas 1,5% m/m







17,0 g/KW h less than 130 rpm

45,0 x n  \©˛ g/KW h when n >130 but <2000 rpm

  9,8  g/KW h when n >2000 rpm       




The above will be enforced by Port State Controlling Officers under the Protocol of 1997.

On 99% of vessels the above values will be reached using low sulphur fuel oils.



Flow Chart for Certification and Responsibilities



Unlawful Acts At Sea 

Diplomatic Conference on the Revision of the SUA Treaties: 10-14 October 2005 Amendments to the Convention for the Suppression of Unlawful Acts Against the Safety of Maritime Navigation, 1988 and its related Protocol, which provide the legal basis for action to be taken against persons committing unlawful acts against ships (and against fixed platforms located on the continental shelf) are set to be adopted by the Diplomatic Conference on the Revision of the SUA Treaties, which meets from 10 to 14 October 2005 at the London headquarters of the International Maritime Organization (IMO), the United Nations specialised agency responsible for safety and security of shipping and the prevention of marine pollution by ships.

The SUA treaties complement the practical maritime security measures adopted by IMO - including SOLAS1 chapter XI-2 (Special measures to enhance maritime security) and the International Ship and Port Facility Security (ISPS) Code, which entered into force in July 2004 - in that they regulate the legal situation in the unfortunate event that a terrorist attack should occur.

The principal purpose of the SUA treaties is to ensure that anyone committing unlawful acts against the safety of navigation will not be given shelter in any country but will either be prosecuted or extradited to a State where they will stand trial. Among the unlawful acts covered by the SUA Convention are the seizure of ships by force; acts of violence against persons on board ships; and the placing of devices on board a ship which are likely to destroy or damage it.


The two draft protocols to amend the 1988 treaties were developed by IMO's Legal Committee and are aimed at ensuring that the legal framework put in place by IMO continues to provide an adequate basis for the arrest, detention, extradition and punishment of terrorists acting against shipping or fixed platforms or when using ships to perpetrate acts of terrorism. The draft protocols broaden the list of offences covered by the treaties and introduce novel provisions to facilitate the boarding of ships where those offences may already be in the process of being committed, with the aim of preventing or neutralizing their potentially damaging consequences.

Work on the revision of the SUA treaties follows from the adoption, in 2001, of IMO Assembly resolution A.924(22), which called for a review of the then existing measures and procedures to prevent acts of terrorism which threaten the security of passengers and crews an the safety of ships.




Lloyd's Register Group is launching 'SEE THREAT', a powerful new web-based risk assessment tool which helps ship operators and their company security officers (CSO) to assess the security threat to their ships. The International Ship and Port Facility Security (ISPS) Code becomes mandatory on 1st July 2004. Pressure is building to demonstrate compliance and only some 3% of ships are currently certified. The Code requires CSOs to use their security assessments and other information as the basis for advising their ships about the threat levels they may encounter, such as terrorism, piracy, labour disputes and civil unrest, among others.

Freak Waves 

Over the last two decades more than 200 large carriers, cargo ships over 200m long, have been lost at sea. Eyewitness reports suggest many were sunk by high and violent walls of water that rose up out of calm seas. But for years these tales of towering beasts were written off as fantasy; and many marine scientists clung to statistical models stating monstrous deviations from the normal sea state occur once every 1,000 years. As part of a project called MaxWave, the European Space Agency (ESA) arranged for two of its Earth-scanning satellites to monitor the oceans with their radars. The shady phenomenon of freak waves as tall as 10 storey buildings had finally been proven, according to ESA. During a three week period they detected 10 giant waves, all of which were over 25m (81ft) high.


To prove the phenomenon or lay the rumours to rest, a consortium of 11 organisations from six EU countries founded MaxWave in December 2000.As part of the project, two Earth-scanning satellites, ERS-1 and ERS-2,  monitored the oceans with their radars. The radars sent back pictures of the sea surface in a rectangle measuring 10 by 5km (6 by 2.5 miles), which were taken every 200km (120 miles). Around 30,000 separate pictures were produced by the two satellites during a three-week period in 2001 - and the data was mathematically analysed. According to ESA the survey revealed 10 massive waves - some nearly 30m (100 ft) high. Ironically, while the MaxWave research was going on, two passenger liners endured terrifying ordeals.The Breman and the Caledonian Star cruise vessels had their bridge windows smashed by 30m waves in the South Atlantic. The Bremen was left drifting for two hours after the encounter, with no navigation or propulsion.




In the next phase of the research, a project called WaveAtlas will use pictures taken, during two years to create a worldwide atlas of freak wave events. The goal is to find out how these strange cataclysmic phenomena may be generated, and which regions of the oceans and seas are most at risk.




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