Section 6 Ship and arrangement requirements

6.1.1 Designated RAS stations are to be provided for RAS operations. RAS stations are to be positioned on the Supplying Ship to maximise compatibility with Receiving Ships and such that, as far as possible, the effects of hull interaction between the Supplying and Receiving Ships are minimised. For some types of naval ships, a reception point for the replenishment of ammunition may be required on the fo'c'sle. The number, type and location of the RAS stations are to be agreed between the designer and Owner but as a guide, for NS1 and NS2 type ships, it is usual practice to have up to six abeam RAS stations (three on the port side and three on the starboard side) located symmetrically about the ship’s centre line. See also Vol 3, Pt 1, Ch 5, 4.2 Functionality 4.2.1.

6.1.2 Each RAS station and the particular RAS operation( s) that may be carried out at the station is to be identified on the general arrangement plan.

6.1.3 Where possible on receiving ships, an abeam RAS station is to be located amidships to maximise crew protection during RAS operations during heavy weather conditions.

6.1.4 RAS stations are to be located so as to permit the observation of each RAS station from two observation positions. In general, the positions selected for the abeam RAS stations are to be port and starboard in the middle portion of the ship between 20 m and 40 m apart symmetrically positioned from amidships and set in so as to provide protection for the RAS crews in heavy seas.

6.1.5 Clear areas are to be provided at each RAS station. Sufficient clear area to enable safe and efficient operation of equipment is to be provided. The area available is to recognise the equipment manufacturer’s recommendations for operations and is to be contained within 30º fore and aft of the normal transverse at the RAS station.

6.1.6 The location of all rigging securing points is to comply with the equipment manufacturer's requirements and agreed between the designer and Owner.

6.1.7 Clear and safe access to all rigging securing points is to be provided. Arrangements are to be provided to ensure that access to those securing points high on the superstructure can be reached safely and speedily. As far as practicable, the arrangements are to be such that there is no requirement for personnel to climb masts to gain access to RAS high points.

6.1.8 The access arrangements to all securing points are not to expose crew to dangerous electromagnetic hazards, see Vol 2, Pt 1, Ch 3, 4.18 Electromagnetic hazards.

6.1.9 In the selection and design of an abeam RAS position for a particular ship, for either a supply or receiving rig, the range of ships with which the ship can operate is to be considered so that the respective stations can be aligned transversely within ± 5º of the normal, without the amidships points of the receiving ship moving further forward than L/10 and L/5 aft of amidships of the supply ship, where L is the length of the supply ship.) See Figure 5.6.1 Alignment of RAS stations.

6.1.10 RAS stations are to be provided such that when two simultaneous RAS operations are being conducted, liquids can be transferred aft of solid cargo.

6.1.11 For requirements relating to electrical equipment for use in explosive gas atmospheres, see Vol 2, Pt 9, Ch 5, 4 Electrical equipment for use in explosive gas atmospheres or in the presence of combustible dusts.

Figure 5.6.1 Alignment of RAS stations

6.2.1 Designated RAS observation positions are to be provided. Each observation position is to be sited to provide a clear field of view of all RAS operations at a particular RAS station. Each RAS station is to be capable of being observed from at least two observation positions.

6.2.2 Each RAS observation position is to be identified on the general arrangement plan. Arcs showing the field of view from each observation position are also to be shown on the general arrangement plan.

6.2.3 Safe access arrangements to each observation position are to be provided.

6.2.4 Each observation position is to be provided with:

1. The necessary communication equipment to enable speedy and efficient communication to ensure safe RAS operations.

2. Equipment to prevent personnel falling or being knocked overboard and a strong point for attachment of a harness arrangement.

6.3.1 Dedicated store arrangements are to be provided for the storage of RAS equipment and fittings. Stores are to be readily accessible from the weather deck and their respective RAS stations.

6.3.2 RAS equipment and fittings associated with potable fresh water RAS operations are to be provided with separate, clean, hygienic and secure conditions.

6.4.1 RAS stations, observation positions and securing points are as far as practicable to be sited clear of sources of electromagnetic energy such as radars, communication transmitters, or lightning conductors. Where such equipment or the swept beam from radar aerials is in close proximity to any RAS facilities, a Risk Assessment is to be undertaken, in accordance with Vol 2, Pt 1, Ch 3, 18 Risk Assessment (RA), to ensure that the dangers of RADHAZ are minimised.

6.5.1 The number, type and location of stores are to be consistent with the routes leading to/from RAS stations. The layout of each store is to recognise the need to rapidly strike down equipment and provisions and is to be agreed between the designer and Owner.

6.5.2 The routes from RAS stations to stores are to be designed to simplify loading and movement of stores, equipment and provisions during RAS operations. The arrangements are to recognise minimising tripping hazards and the need for two people to pass without restriction.

6.5.3 The entrances to the interior of the ship from each RAS station are to be designed to prevent the ingress of sea-water when undertaking RAS operations in heavy weather conditions.

6.6.1 Depending on the intended functional requirements of the ship, each RAS station that is designed to receive and/or supply solids during RAS operations is to have a designated dump area in the case of receiving ships and/or a dispatch area for supplying ships. The dump area is to be suitably stiffened and designed to withstand the impact loads that may arise whilst landing stores and equipment on board during RAS operations.

6.6.2 The extent of each dump area is to exceed the foot print of the largest pallet by not less than 1 metre in each direction. A factor of safety of not less than four times the maximum load to be transferred is to be used in the design of the structure.

6.6.3 The location of the dump area and/or dispatch area within the RAS station is to be agreed between the designer and Owner and is to centre on the high point where applicable.

6.6.4 For other structural requirements, see Vol 1, Pt 4, Ch 2 Military Load Specification.

6.7.1 RAS stations, observation positions and securing points are to be sited such that exposure to high intensity noise (above 85 db) for personnel involved in RAS operations is as low as reasonably practicable.