Standards for fuel to be used on ships

Malcolm Latarche

Malcolm Latarche · 12 May 2017


Although the IMO has set standards for fuel to be used on ships, at least with regard to sulphur levels, there is no compunction on bunker suppliers to follow the regulations and as a consequence there is quite often a mismatch between the quality of fuel needed to comply with MARPOL and that actually supplied. The problem is compounded because as with most IMO regulation, enforcement by port states takes little account of commercial reality.

Almost all fuels are ordered using contracts that require the fuel to meet ISO 8217 standards. This standard contains reference to another ISO standard (ISO 4259) that describes how test results are to be interpreted. However, the MARPOL sample that is taken as part of all bunker supplies is tested when necessary according to Annex VI of MARPOL Appendix VI.

Attempts by the industry to persuade the IMO to recognise the problem were made at MEPC68 in May 2015. Despite opposition from many states including the US, Norway, Sweden and Germany, the meeting did agree to establish a working group to investigate and report at MEPC69 in 2016. At MEPC 69 the working group were unable to report consensus and the matter was held over for further consideration at MEPC 71 which takes place in July 2017.

A need for procedures

Annex VI is not the only aspect of MARPOL applying to bunkering procedures.
Bunkering connections must be fitted with save-alls to retain any spills during bunker loadings and it is good practice to take further precautions as well. Most safe management systems required to comply with the ISM Code would recognise bunkering as a key shipboard operation, a potential emergency situation and a potential threat to the environment. It would therefore be expected that a written procedure is in place and pollution control materials ready to hand and scuppers plugged.

Annex VI also includes a requirement for the changeover process from standard to low sulphur fuel to be recorded when a ship is preparing to enter an ECA or for other reasons. The main purpose of this is to permit PSC inspectors to determine if, at the time the ship entered the ECA, the correct type of fuel was being used in the engines.

It is not possible for an instant switchover to a different fuel to be made because this is unsafe and could result in damage to most engines. The changeover process can take several hours to be managed safely although there are now automated means to do this.

Safety regulations concerning fuels and lubricants are mostly concerned with their flammable nature. As previously mentioned there is a limit of 60ºC on the flashpoint of marine fuels except for fuel for emergency pumps where a lower limit of 43ºC is permitted providing the fuel is stored away from machinery spaces. Setting the SOLAS flashpoint at 60ºC precludes the use of road fuels for engines in ECAs because a limit of 57ºC usually applies to that sector. Some other aspects of the SOLAS requirements for fuel systems include:-

  • As far as practicable, parts of the oil fuel system containing heated oil under pressure exceeding 0.18 N/mm² shall not be placed in a concealed position such that defects and leakage cannot readily be observed. The machinery spaces in way of such parts of the oil fuel system shall be adequately illuminated.
  • Fuel oil, lubrication oil and other flammable oils shall not be carried in forepeak tanks. Safe and efficient means of ascertaining the amount of oil fuel contained in any oil fuel tank shall be provided.
  • Oil fuel pipes and their valves and fittings shall be of steel or other approved material, except that restricted use of flexible pipes shall be permissible in positions where the Administration is satisfied that they are necessary. Such flexible pipes and end attachments shall be of approved fire-resisting materials of adequate strength and shall be constructed to the satisfaction of the Administration.
  • External high-pressure fuel delivery lines between the high-pressure fuel pumps and fuel injectors shall be protected with a jacketed piping system capable of containing fuel from a high-pressure line failure. A jacketed pipe incorporates an outer pipe into which the high-pressure fuel pipe is placed, forming a permanent assembly. The jacketed piping system shall include a means for collection of leakages and arrangements shall be provided with an alarm in case of a fuel line failure.
  • Oil fuel lines shall not be located immediately above or near units of high temperature, including boilers, steam pipelines, exhaust manifolds, silencers or other equipment required to be insulated.
  • As far as practicable, oil fuel lines shall be arranged far apart from hot surfaces, electrical installations or other sources of ignition and shall be screened or otherwise suitably protected to avoid oil spray or oil leakage onto the sources of ignition. The number of joints in such piping systems shall be kept to a minimum.
  • Components of a diesel engine fuel system shall be designed considering the maximum peak pressure which will be experienced in service, including any high-pressure pulses which are generated and transmitted back into the fuel supply and spill lines by the action of fuel injection pumps. Connections within the fuel supply and spill lines shall be constructed having regard to their ability to prevent pressurised oil fuel leaks while in service and after maintenance.
  • In multi-engine installations which are supplied from the same fuel source, means of isolating the fuel supply and spill piping to individual engines, shall be provided. The means of isolation shall not affect the operation of the other engines and shall be operable from a position not rendered inaccessible by a fire on any of the engines.
  • Surfaces with temperatures above 220°C which may be impinged as a result of a fuel system failure shall be properly insulated.
  • Precautions shall be taken to prevent any oil that may escape under pressure from any pump, filter or heater from coming into contact with heated surfaces.

After more than a century of using oil as fuel for ships, it is not surprising that most regulation covers oils either as fuels or as lubricants. The only other fuel commonly in use today is LNG and until recently it was not really covered by any international regulation.

The first ships to use LNG were LNG carriers and the gas is not loaded as fuel but is provided by the boil off from the cargo which would otherwise have been vented to the air for safety reasons. The boil off gas is used to run either a steam turbine plant or more recently a dual-fuel engine. In addition to the many LNG carriers powered by gas there are a growing number of other ship types that have been built over the last decade or so.

Most are ferries or offshore vessels operating under the Norwegian flag but the numbers also include ferries flagged in other Scandinavian countries and Canada and a handful of US-flagged container ships. So far all of the vessels have required flag state approval on a case-by-case basis because of the lack of any internationally agreed regulations and standards for gas fuelled vessels.

That has now changed with the adoption at MSC 95 in June 2015 of the International Code of Safety for ships using gases or other low flashpoint fuels (IGF Code). The code has been in development for some years and is based upon interim guidelines contained in MSC Resolution 285(86) which was adopted in June 2009. While the guidelines were voluntary, the IGF Code is now incorporated into SOLAS and its requirements re now mandatory. The IGF Code covers bunkering procedures as well as the storage and use of LNG as fuel onboard.

The IGF Code involved amendments to SOLAS chapter II-1 (Construction – Structure, subdivision and stability, machinery and electrical installations) that included amendments to Part F Alternative design and arrangements, to provide a methodology for alternative design and arrangements for machinery, electrical installations and low-flashpoint fuel storage and distribution systems; and a new Part G Ships using low flashpoint fuels, to add new regulations to require ships constructed after 1 January 2017 to comply with the requirements of the Code. There are related amendments to chapter II-2 and Appendix (Certificates).

The IGF Code contains mandatory provisions for the arrangement, installation, control and monitoring of machinery, equipment and systems using low-flashpoint fuels, focusing initially on LNG. It addresses all areas that need special consideration for the use of low-flashpoint fuels, taking a goal-based approach, with goals and functional requirements specified for each section forming the basis for the design, construction and operation of
ships using this type of fuel.

The IMO has also adopted related amendments to the STCW Code to include new mandatory minimum requirements for the training and qualifications of personnel on ships subject to the Code. The amendments also came into force date on 1 January 2017, in line with the SOLAS amendments related to the IGF Code.

A matter of record

In its attempts to control pollution by oil, IMO regulations not only deal with practical matters but also cover the administrative aspects by the mandatory use of Oil Record Books. The Oil Record Book is supposed to detail the management of all fuel and other oil on board and the fuel consumption and disposal of waste oils and used consumables such as filters that will by their very nature be contaminated with oil waste.

Maintaining the ORB accurately is essential for ships if they are to avoid PSC intervention and prosecution. The vast fines and custodial sentences meted out by US courts and other legal authorities are rarely direct punishment for illegal discharges – discharges outside territorial waters would not be actionable – but false record keeping since the ORB is considered as a legal document.

In addition to the international conventions, there are also a number of regional regulations concerning emissions which are influenced by fuel choice. Probably the most well-known are the EU’s directive on using ultra low-sulphur fuel in ports and the California Air Resources Board requirement for ships to switch from heavy fuel oil to low-sulphur marine distillate fuel before entering “Regulated California Waters.”

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