A classification society is a non-governmental organization that establishes and maintains technical standards for the construction and operation of ships and offshore structures. Classification societies certify that the construction of a vessel comply with relevant standards and carry out regular surveys in service to ensure continuing compliance with the standards.
Regarding alternative fuels as methanol, different classifications societies like DNV-GL and LR creates their own interpretation of IMO:s guidelines, the overall content is more or less similar but some parts might be more conservative or vice versa. If the classifications society approves the design, the shipowner can be confident that their vessel is reaching a similar safety standard as IMO demands.
DNV GL and LR have taken slightly different paths for the class approval process. The LR Ship rules dictate that when designing an unconventional arrangement, a formal risk assessment approach shall be taken with MSC/Circ. 1023 as a starting- point. This approach is somewhat time- consuming, with the benefits of a well thought through result and great open- mindedness to unconventional solutions. DNV GL has adopted a more prescriptive model, with no requirements for risk assessment sessions.
+ DNV-GL, RU-SHIP Part 6 Chapter 2 Section 6
As mentioned, Det Norske Veritas (Norway) and Germanischer Lloyd (Germany) follows a prescriptive model for their LOW FLASHPOINT LIQUID FUELLED ENGINES (LFL fuelled). With an approved design fulfilling all criterions, having an equivalent level of integrity in terms of safety and availability as that which can be achieved with new and comparable conventional oil-fuelled main and auxiliary machinery, the vessel will be given an additional notation “LFL fuelled”.
The scope for additional class notation LFL fuelled includes requirements from the vessel's LFL fuel bunkering connection up to and including the consumers. The rules in this section have requirements for arrangement and location of fuel tanks and all spaces with fuel piping and installations, including requirements for entrances to such spaces. Hazardous areas and spaces due to the fuel installations are defined.
+ Lloyd's Register, Rules for the Classification of Methanol Fuelled Ships
LR rules intends to establish requirements for machinery using methanol as a fuel. The aim of the requirements is to provide a level of safety in respect of the ship’s occupants and a level of dependability in respect of the ship’s essential services, such as propulsion and electrical power that is commensurate with conventional oil-fuelled propulsion and auxiliary machinery. These requirements are in addition to the applicable requirements of the Rules and Regulations for the Classification of Ships.
Ships operating on methanol and complying with the requirements of these Rules will be eligible for assignment will have an additional notation as follows: LFPF(GF, ML).
LR follows a risk-based approach as mentioned, where the purpose is to: evaluate safety considerations that are specific to the application, evaluate dependability of essential services and specially consider arrangements which deviate from the requirements of these Rules.
To fulfil this approach several different risk-analysis must be considered, they are as follows:
- System safety assessment
- System dependability assessment
- Failure modes and effects analysis (FMEA) of the critical system elements
- Hazardous areas classification study
- System hazard and operability study (HAZOP)
- Bunkering safety study
- Other risk-based studies
+ India Register of Shipping, Guidelines on Methanol Fueled Vessels
A guideline for methanol fueled vessels is established by the India Register of Shipping (IRS). The goal is to provide provisions for the arrangement, installation, control and monitoring of machinery, equipment and systems, helping ship owners, ship designers and shipyards to design, build and operate methanol fueled ships. Though the guideline is focus on methanol, ethanol fueled vessels can apply the same guideline.
The guideline includes 18 sections, they are developed considering goal based approach MSC.1/Circ.1394. The last two sections, Section 17 and Section 18, are provided for guidance for stakeholders, instead of strictly class matters.