Section 1 General requirements
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Naval Ships, January 2023 - Volume 3 Additional Class Notations - Part 1 Ship Type Capability - Chapter 5 Replenishment at Sea (RAS) Systems - Section 1 General requirements

Section 1 General requirements

Parent topic: Chapter 5 Replenishment at Sea (RAS) Systems

1.1 Application

1.1.1 This Chapter states the requirements for Replenishment At Sea (RAS) systems installed in naval ships for the purpose of supplying and receiving solid or liquid supplies. The Chapter also states the requirements for Vertical Replenishment (VERTREP) and light jackstay RAS systems which may be used for transfer of personnel and light stores between naval ships. The requirements are in addition to the relevant requirements contained in Vol 1 Ship Structures and Vol 2 Machinery and Engineering Systems of these Rules. Other arrangements to supply solid and liquid stores by means of RAS will be specially considered.

1.1.2 The requirements in this Chapter cover arrangements, deck equipment, piping and control systems necessary for RAS operations.

1.1.3 The extent of RAS systems and facilities are subject to agreement between the designer and Owner. The classification approval process will involve assessment of the safety of the proposed facilities from concept to through life operability and de-commissioning. RAS operations are extremely hazardous and those involved in the development of such systems need to address safety issues to minimise the risks to the ship, personnel and the environment. Operational procedures and regular crew training are essential to minimise these risks and to reduce hazards to as low as reasonably practicable.

1.1.4 NATO interoperability requirements are to be specified by the Owner/Operator and are detailed in ATP16 (latest version).

1.2 RAS terminology

1.2.1 RAS terminology is defined in Vol 3, Pt 1, Ch 5, 1.2 RAS terminology 1.2.2.

1.2.2  RAS station: The physical location of a combination of deck area and associated equipment that provides a ship with the capability to receive or deliver solids, liquid or personnel by means of passing RAS equipment between ships whilst underway. Note these Rules are only applicable to naval ships intended for supplying and receiving solid or liquid supplies and for personnel transfer.

1.2.3  VERTREP Operational Area (VOA): This is the authorised area within which VERTREP operations are conducted. It includes the clear deck space for helicopter rotor, fuselage and landing gear, and VERTREP load clearances (including dump areas).

1.2.4  Abeam Replenishment: The transfer of solid cargo, personnel or liquid cargo by means of passing RAS equipment between ships while underway when the Receiving Ship will normally station-keep on the Supplying Ship. Circumstances may exist when the Supplying Ship will be required to station-keep on the Receiving Ship.

1.2.5  Astern Replenishment: The transfer of liquid cargo by means of a hose(s) while underway with the Receiving Ship maintaining station astern of the Supplying Ship.

1.2.6  Vertical Replenishment (VERTREP): Transfer of solid cargo by underslung load from a helicopter and the winching of personnel where a ship is not provided with a flight deck.

1.2.7  Supplying Ship: The ship that supplies the RAS equipment and cargo.

1.2.8  Receiving Ship: The ship that receives the RAS equipment and transferred cargo.

1.2.9  Dump Area: A designated clear area that is provided at VERTREP and Abeam RAS stations for receiving stores.

1.3 Safety

1.3.1 Replenishment at sea between two vessels underway (particularly abeam RAS) is classified as the most hazardous peacetime seamanship evolution conducted by the naval and supply ships. It is important that the following areas are considered when designing, building, operating and maintaining RAS systems:

  1. Close Proximity of Vessels Underway: Station-keeping and the availability of propulsion and steering to maintain constant speed and heading are vital to avoid collision, due to the pressure interaction areas between ships in close proximity underway.

  2. Handling of Explosives and Bulk Ammunition: Replenishment of solids may include ammunition and explosives classified as UN hazard category 1. Particular note is to be taken of the enhanced factors of safety and equipment test periodicities that are required for mechanical handling equipment used for such purposes.

  3. Transfer of Personnel and Explosives: Lifting appliance codes of practice stipulate enhanced factors of safety and more frequent testing for preventive maintenance of mechanical handling equipment used for transfer of personnel and explosives.

  4. Safety of Personnel: Care is to be taken in the design and operation of RAS systems to minimise hazards to personnel who have to work in the vicinity of the RAS station. The likelihood of personnel being injured or knocked overboard by RAS equipment and operating gear is to be assessed and suitable guard rails are to be provided as necessary.

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