Section 2 Scope of the Rules

2.1 Applicable ship types

2.1.1 The Rules are applicable to naval ships designed and constructed for the purpose of carrying and operating naval systems. For the purposes of Classification, naval ships can be grouped into five categories as follows:

NS1 ships

This category covers ships used for the deployment of aircraft or equipment and ships which may be used as centres of command. Designed for world wide operation and usually supported by ships from the NS2 category.

Typically it will cover ships above 140 m in length with a deep displacement of 10000 tonnes or more. It will include aircraft carriers, helicopter and amphibious support ships, and assault ships.
NS2 ships

This category covers ships used to defend NS1 ships as part of a task force or act as independent units. They may have a variety of sole or multiple roles including air defence, anti submarine, sea defence, shore support and will be designed for world wide operation.

Typically it will cover ships of length of 70 m to 140 m with displacements of 1300 tonnes to 20000 tonnes. NS2 ships may be described as cruisers, frigates, destroyers, corvettes or similar.
NS3 ships

This category covers ships that have a front line role but are not covered by the above descriptions. This category includes a variety of ships typically below 1500 tonnes displacement. They may operate independently or as part of a task force and are usually designed and constructed for specific roles such as mine sweeping, beach landings, coastal defence or fast patrol duties. A restricted service area may be specified.
NS(SR) ships

This category covers auxiliary naval ships used for the support of civil and naval operations. They may have a variety of roles including the movement of military and other personnel, ammunition, vehicles, stores and fuels and the transfer of such to other naval ships. They do not have a defined military role but may have a limited self-defence capability. In general, the ships will comply with LR’s Rules and Regulations for the Classification of Ships, July 2022 and any relevant requirements in Vol 1, Pt 1, Ch 2, 3.5 Ship type notations 3.5.6 for new vessels and any relevant requirements in Vol 1, Pt 1, Ch 3, 16 Classification of ships built under survey to LR Classification Rules and Regulations other than LR Naval Ship Rules and Regulations for existing vessels; and satisfy as far as practicable the requirements of the International Conventions applicable to the ship type. Any deviation from the applicable International Conventions requires agreement with the Owner or Naval Administration and where applicable the National Administration. A Design and Operating Scenario Statement declared by the Owner stating the role of the ship in terms of the carriage of equipment, personnel, stores and fuels, in accordance with Vol 1, Pt 1, Ch 2, 3.5 Ship type notations 3.5.7, is to be acceptable to LR. Where an NS(SR) notation is applicable, the requirements of the Rules and Regulations for the Classification of Ships, July 2022, Pt 1, Ch 2 Classification Regulations are not applicable and the requirements of this Chapter are to be applied.
NS(SSC) ships

This category is limited to ships typically below 1500 tonnes displacement or 110 m length. They do not have a defined military role but may have a limited self-defence capability and are usually designed and constructed for constabulary purposes such as coastal defence or patrol duties. In general, the ships will comply with LR's Rules and Regulations for the Classification of Special Service Craft, July 2022 and any relevant requirements in Vol 1, Pt 1, Ch 2, 3.5 Ship type notations 3.5.6 for new vessels or Vol 1, Pt 1, Ch 3, 16 Classification of ships built under survey to LR Classification Rules and Regulations other than LR Naval Ship Rules and Regulations for existing vessels; and satisfy as far as practicable the requirements of the International Conventions applicable to the ship type. Any deviation from the applicable International Conventions requires agreement with the Owner or Naval Administration and where applicable the National Administration. A Design and Operating Scenario Statement declared by the Owner stating the role of the ship in terms of the carriage of equipment, personnel, stores and fuels, in accordance with Vol 1, Pt 1, Ch 2, 3.5 Ship type notations 3.5.7, is to be acceptable to LR. Where an NS(SSC) notation is applicable, the requirements of the Rules and Regulations for the Classification of Special Service Craft, July 2022, Pt 1, Ch 2 Classification Regulations are not applicable and the requirements of this Chapter are to be applied.

There are special requirements for hovercraft, mine-sweepers, landing ships, which are to be designed in accordance with the appropriate Sections of relevant LR's Rules and Regulations.

2.2 Definitions

2.2.1 For the purpose of the Rules and Class notations, the definitions given in Vol 1, Pt 1, Ch 2, 2.2 Definitions 2.2.2 to Vol 1, Pt 1, Ch 2, 2.2 Definitions 2.2.15 will apply.

2.2.2 Clear water. Water having sufficient depth to permit the normal development of wind generated waves.

2.2.3 Designer. The organisation which provides the design and constructional plans.

2.2.4 Fetch. The extent of clear water across which a wind has blown before reaching the ship.

2.2.5 Laid-up notation. A ship not under repair or not actively employed may be assigned the laid-up notation in order to maintain the ship in class subject to agreement by the Classification Committee. A general examination of the hull and machinery is to be carried out in lieu of the Annual Survey. An Underwater Examination (UWE) is to be carried out in lieu of the Special Survey. See;

The schedule of survey activities for a ship which is laid-up with personnel onboard and/or with some degree of ongoing system operation during the laid-up period will be specially considered.

2.2.6 Maximum speed. Maximum speed is the speed, in knots, achieved at the maximum continuous power for which the ship is certified in smooth water.

2.2.7 Mono-hull ship. A mono-hull ship is a ship whose single hull may be of displacement form or of a semi-planing or planing form subject to some support by hydrodynamic lift.

2.2.8 Naval Administration. An authority or authorities nominated by the Owner responsible for providing regulation associated with procurement and support of the ship. The Naval Administration may also be responsible for identifying appropriate standards, auditing and certification. The Naval Administration could be a Government department, Statutory Authority, LR or an independent organisation with appropriate standing. In the absence of a clearly defined Naval Administration, LR will refer to the Owner.

2.2.9 Navy. The operator of the ship. The Navy may also be the Owner.

2.2.10 Owner. Generally, this will be the government department responsible for naval procurement and support. In certain circumstances, the Navy may operate ships chartered from other Owners, in which case the Owner as defined in these regulations is to be agreed with LR on a case by case basis.

2.2.11 Client. LR’s point of contact with the organisation contracting it to undertake work.

2.2.12 Operational envelope. The operational envelope will be provided by Lloyd’s Register as an Annex to the Classification Certificate and defines limits of the vessel’s service in terms of operational speeds, wave heights, displacements, service area and time required to seek refuge where this is required.

2.2.13 Reasonable weather. Reasonable weather is defined as wind strengths of force six or less on the Beaufort scale, associated with:

Sea states within the operational envelope which are sufficiently moderate to ensure that green water is taken on board at infrequent intervals only or not at all.
Motions such as do not impair the efficient operation of the ship.

2.2.14 Sheltered water. Water where the fetch is six nautical miles or less.

2.2.15 Stability information. Documents required for stability certification.

2.2.16 Standard. A set of appropriate requirements and/or criteria that are to be agreed by the Naval Administration prior to the plan appraisal stage.

2.2.17 Concept of Operations. The Concept of Operations (ConOps) is a statement of an Owner’s intentions for the operation of the ship. The ConOps describes the ship’s intended service in terms of purpose and function and is to include, but not be limited to, information on the following: crewing, operational speeds, wave heights, displacements, service area, temperatures, motions, aircraft and boat operations; arrangements under reasonably foreseeable, normal and abnormal conditions. The ConOps is to be provided by the Owner. LR may accept alternative documents where these provide the information which would be included within the ConOps, in such cases the relevant sections providing the information required to provide equivalence with the ConOps are to be identified.

2.2.18 System Operational Concept. A System Operational Concept is a description of the intended operation of each of the major ship systems, that is those comprised of sub-systems and equipment referenced within the Rules. The System Operational Concept is to demonstrate that the systems’ architecture, configuration and criticality meet the requirements of the operational scenarios defined by the ConOps. The System Operational Concept statements are to be agreed between the designer and the Owner. LR may accept alternative documents where these provide the information which would be included within the System Operational Concept. In such cases the relevant sections providing the information required to provide equivalence with the System Operational Concept are to be identified.

2.2.19 System Design Description. The System Design Description is a document that describes the design of a system or equipment. The System Design Description details the system’s capability and functionality under all normal and reasonably foreseeable abnormal operating and fault conditions. The System Design Description documents are to be agreed between the designer and the Owner. LR may accept alternative documents where these provide the information which would be included within the System Design Description. In such cases the relevant sections providing the information required to provide equivalence with the System Design Description are to be identified.

2.2.20 Engineering and Safety Justification. A statement or report which provides a reasoned and compelling argument supported by a suitable body of evidence, that either the system or sub-system under consideration will operate as intended for a defined application in a defined environment or in the case of a deviation from the Rules, evidence that the proposed alternative arrangements are equivalent. This is to include details of the safety implications and protective measures to be implemented to mitigate risks associated with the system or alternative arrangements. It may include references to design standards used, assumptions and technical evidence such as analysis or test reports. Where required this is to be derived from a Risk Based Analysis in accordance with Vol 1, Pt 1, Ch 2 Classification Regulations. It may include:

Possible failure modes of internal components and measures adopted to mitigate such failures that may have an effect on the internal machinery or the surrounding environment/structures/systems, taking due account of suitability of materials and the effects of stress raisers, etc.
Operating parameters and any required limitations.
Details of life-limited critical components, including their declared lives and residual lives or balance of planned life remaining, in terms of operating time or operating cycles, or where life is derived from declared acceptance criteria, and the associated maintenance strategies.
Installation arrangements.
Details of potential failures that could lead to hazardous or major consequences and/or degradation in systems performance that could lead to failures and which are to be notified to the Operators.
Common failure modes and measures to minimise potential single points of failure such as system redundancy and environmental separation of equipment and services.
Identification of failure modes of the defined integrated system.

In addition, an Engineering and Safety justification is to be provided for each deviation from the Rule requirements, such deviations are normally raised by the designer or Builder and are to be agreed with the Owner and Naval Administration. In some cases a full justification and Risk Assessment may be required. See Requirements for Machinery and Engineering Systems of Unconventional Design, Vol 2, Pt 1, Ch 2 Requirements for Machinery and Engineering Systems of Unconventional Design and Risk Assessment (RA) Vol 2, Pt 1, Ch 3, 18 Risk Assessment (RA).