Section 5 Electromagnetic compatibility
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Submarine Assurance Framework, July 2022 - Volume 1 Submarine Assurance - Part 4 Whole Boat Requirements - Chapter 3 Requirements for Systems - Section 5 Electromagnetic compatibility

Section 5 Electromagnetic compatibility

5.1 Functional objective

5.1.1 The range of electromagneticinterference which can be experienced by a submarine shall be defined for all foreseeable operating conditions.

5.1.2 The electromagnetic emissions from submarine, systems, equipment and components shall not be a risk to: the submarine systems, embarked persons, munitions or flammable atmospheres.

5.1.3 The Section does not cover portable electrical devices. These should be controlled by operating procedures.

5.2 Performance requirements

5.2.1 Electromagnetic (EM) threats are to be controlled using the appropriate methods for the EM emitters and susceptible systems, equipment or components within the submarine. This includes applying standards agreed by the Naval Administration and conducting an EM threat assessment.

5.2.2 The EM threat assessment and EM vulnerability assessment is to identify all the internal and external EM threats and vulnerabilities or hazards and identify all the processes, procedures and mitigation requirements which are to be applied to achieve the required electromagnetic compatibility (EMC) between the submarine equipment and systems. The EM Threat assessment is to consider the risk to people, explosive atmospheres and munitions associated with electromagnetic radiation.

5.2.3 EM pulse and electromagnetic signature are to be defined as a survivability and signature requirement. See Vol 1, Pt 4, Ch 8 Survivability.

5.2.4 The EM environmentshall be defined throughout the submarine for normal, abnormal and emergency operating conditions. Limits are to be set taking into account the electrical and mission system equipment likely to be on board the submarine, personnel exposure and risk to flammable atmospheres and munitions.The definition of the EM environment shall include:

  1. Conducted low frequency interference;
  2. Conducted radio interference;
  3. Radiated radio frequency fields;
  4. Fast low-energy transients (bursts);
  5. Slow high-energy transients (surges); and
  6. Electrostatic discharge (ESD).

5.2.5 The localised maximum transient EM environmentshall be defined for the areas where there are high power emitters which exceed the general EM environment, e.g. bridge fin.

5.2.6 The submarine, systems, equipment and components shall be protected from the effects of lightning.

5.2.7 The submarine, systems, equipment and components that are required to operate and are susceptible to a particular EM environmentare to be identified. They shall be able to operate and be immune to the defined levels of interference for that location or be fitted with suitable protection measures.

5.2.8 The EM environment defined shall take account of the impact on the embarked persons, suitable control measures are to be put in place to manage exposure.

5.2.9 The EM environment defined shall take account of the impact on flammable atmospheres which may be generated in or near the submarine, and suitable control measures are to be put in place to reduce the risk of ignition. The effect of electrostatic discharge on such operations is also to be considered.

5.2.10  The EM environment defined shall take account of the impact on munitions, suitable control measures are to be put in place to reduce the risk of a munition reaction.

5.2.11 An EMC Management Plan shall be provided which details the submarine’s operational role and defines the EM environment in normal, abnormal and emergency operating conditions, required submarine functions in the different EM environments, EM systems requirements and organisational responsibilities.

5.2.12 An EMC Control Plan shall be provided which defines the design and mitigation measures to be taken to achieve EMC in the agreed EM threat environment. These are to include, but are not limited to the following:

  1. The EM threats;
  2. The zoning concept used;
  3. Exposure limits for personnel, munitions and hazardous atmospheres;
  4. A declaration of the emission levels;
  5. A declaration the minimum immunity level;
  6. Shielding techniques and requirements;
  7. Cabling requirements;
  8. Filtering requirements; and
  9. Grounding requirements.

5.2.13 Levels of EM emission from the submarine equipment shall be known.

5.2.14 An EMC Test Plan shall be provided which defines the verification and validation requirements, which are to include the analysis, inspection, demonstration and testing requirements. The EMC test plan is to include verification of the EM environment.

5.2.15 The EMC Management Plan, EMC Control plan, and EMC Test plan are to be maintained for the life of the submarine and updated following modification or change. The effect of modifications and changes are to be evaluated to confirm performance requirements continue to be met.


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