Section 3 Risk-based studies

3.1.1 The purpose of the risk-based studies is to:

1. evaluate safety considerations that are specific to the application;

2. evaluate dependability of essential services;

3. specially consider arrangements which deviate from the requirements of these Rules.

3.2.1 A system safety risk assessment shall be undertaken. The objectives of the assessment are to:

1. evaluate safety risks associated with the use of methanol that are application specific, such as the specific location of tanks, machinery, equipment and accommodation;

2. evaluate safety risks associated with the use of methanol where it is proposed to deviate from the requirements of these Rules;

3. demonstrate that an appropriate level of safety is achieved that is commensurate with conventional oil-fuelled propulsion and auxiliary machinery.

3.2.2 Where the risks cannot be eliminated, an inherently safer design shall be sought in preference to operational/procedural controls. This shall focus on engineered prevention of failure (e.g. a minimised number of connections, increased reliability, and redundancy). Where this cannot be achieved or is insufficient, protection of occupants should focus on:

1. firstly, passive means (e.g. physical barriers, separation, absence of ignition sources);

2. secondly, active means (e.g. detection, isolation, ventilation and extinguishment).

Both passive and active means may be required to demonstrate an appropriate level of safety.

3.2.3 The assessment may identify the need for additional safety measures in addition to those specifically stated in these Rules. Where additional safety measures are identified, evidence is to be provided that demonstrates how they are implemented and validated.

3.2.4 As a minimum, the scope of the assessment shall consider:

1. normal operation, start-up, normal shutdown, non-use, and emergency shutdown of the system;

2. physical tank, machinery and equipment layout, arrangements and location;

3. foreseeable mechanical failures, electrical failures and human errors.

3.2.5 The assessment shall be undertaken to a recognised Standard (e.g. ISO 31010, Risk management – Risk assessment techniques) and in accordance with LR’s ShipRight procedure Assessment of Risk Based Designs and associated annexes.

3.3.1 A system dependability assessment shall be undertaken. The objectives of the assessment are to:

1. demonstrate the dependability of the system during all normal and reasonably foreseeable abnormal conditions where essential services are reliant upon the system for their intended operation; and

2. demonstrate that an appropriate level of dependability is achieved that is commensurate with conventional oil-fuelled machinery.

3.3.2 As a minimum, the scope of the assessment shall consider:

1. the redundancy of fuel storage and supply; and

2. the reliability and availability of machinery, equipment and components to maintain essential services.

3.3.3 Essential services include but may not be limited to those defined in the Rules for Ships, Pt 6, Ch 2, 1.6 Definitions 1.6.1 and the items of equipment listed in the Rules for Ships, Pt 5, Ch 1, 1.1 Machinery and equipment to be constructed under survey 1.1.1.

3.3.4 The assessment shall be undertaken to a recognised Standard (e.g. IEC 60300-3-1, Dependability management Part 3-1: Application guide – Analysis techniques for dependability – Guide on methodology).

3.4.1 An FMEA shall be undertaken on key components of the system as identified in the system safety risk assessment (e.g. may include the tank master isolation valve and/or the master fuel valve). The objectives of the analysis are to identify:

• potential failures;
• consequences of failure;
• means to eliminate or prevent failure;
• means to eliminate or minimise consequences.

3.4.2 The analysis may identify the requirement for safety measures in addition to those specifically stated in these Rules. Where additional safety measures are identified, evidence is to be provided that demonstrates how they are implemented and validated.

3.4.3 As a minimum, the scope of the analysis shall consider the ‘fail safe’ condition, location and arrangement of the critical system elements.

3.4.4 The analysis shall be undertaken to a recognised Standard (e.g. as outlined in ISO 31010: Risk management - Risk assessment techniques).

3.5.1 A hazardous areas classification study shall be undertaken. The objective of the study shall identify areas or spaces in which a flammable/explosive atmosphere is present or may be expected to be present, such that potential sources of ignition can be eliminated or controlled, and access to such areas restricted.

3.5.2 The scope of the study shall consider all machinery and equipment which could represent a source of release of fuel in:

1. normal operation, start-up, normal shutdown, non-use, and emergency shutdown of the fuel system;

2. equipment intended for recovery from unintended releases of fuel.

3.5.3 The study shall be undertaken by suitably qualified and experienced personnel to a recognised Standard; IEC 60079-10-1: Explosive atmospheres – Part 10-1: Classification of areas – Explosive gas atmospheres.

3.6.1 A HAZOP study shall be undertaken. The objectives of the study are to:

1. identify potential deviations from the intended operation of the fuel system;

2. identify the causes of each deviation, and the consequences for safety (see Ch 1, 3.2 System safety risk assessment and Ch 1, 3.4 Failure modes and effects analysis (FMEA) of the critical system elements) and dependability (see Ch 1, 3.3 System dependability assessment);

3. list safeguards to minimise causes and consequences;

4. determine and recommend if further safeguards should be considered.

3.6.2 Using a detailed piping and instrumentation diagram (P&IDs) and supporting information and plans, the scope of the study shall consider normal operation, start-up, normal shutdown, non-use, and emergency shutdown of the fuel system.

3.6.3 The study shall be undertaken to a recognised Standard (e.g. ISO 31010: Risk management – Risk assessment techniques) in accordance with LR’s ShipRight procedure Assessment of Risk Based Designs and the associated annexes.

3.7.1 A bunkering safety study shall be undertaken. The objectives of the study are to review the bunkering equipment and arrangements, so as to:

1. identify causes and safety consequences of potential fuel releases during connection, preparation and disconnection of bunkering equipment, and during transfer of fuel;

2. list safeguards to minimise causes and consequences;

3. determine and recommend if further safeguards or procedural changes should be considered.

3.7.2 The study shall be undertaken to a recognised Standard (e.g. ISO 31010: Risk management – Risk assessment techniques) in accordance with LR’s ShipRight procedure Assessment of Risk Based Designs and the associated annexes.

3.8.1 Other studies may be required as identified by the risk assessment (see Ch 1, 3.2 System safety risk assessment), and these may identify the requirement for safety measures in addition to those specifically stated in these Rules. Where additional safety measures are identified, evidence is to be provided that demonstrates how they are implemented and validated.