Section 7 Ship operating system requirements

7.1.1 A conning location for the officer in charge of RAS operations is to be provided on the navigating bridge with a duplicated position on both bridge wings. The location is to be agreed between the designer and Owner and be included in the System Operational Concept.

7.1.2 From the conning position, the officer in charge is to be able to observe the ship’s heading and the relative movement of the two ships conducting RAS operations. Also, a gyro compass readout and rudder angle indicator are to be readily visible from the conning position.

7.1.3 Where specified an additional emergency conning position for use in the event of the bridge conning position being out of service may be required. The agreed location and arrangements are to be agreed between the designer and Owner and are to be specified in the System Operational Concept.

7.2.1 The design of the propulsion and steering machinery is to provide arrangements that will permit RAS operations to be undertaken at minimum risk recognising a single failure in equipment associated with continuous propulsion and steering capability. The requirements of the machinery class notation PSMR in Vol 3, Pt 1, Ch 3 Propulsion and Steering Machinery Redundancy are to be complied with as applicable. As a guide, ships are to be designed to be capable of maintaining continuous course and speed for at least one minute to facilitate safe emergency breakaway in the event of equipment failure in propulsion and steering systems.

7.2.2 Where ships are fitted with single screw propulsion and single rudder arrangements or having the additional L character assigned to a machinery redundancy notation, see Vol 3, Pt 1, Ch 3 Propulsion and Steering Machinery Redundancy, an evaluation of a detailed engineering and safety justification will be required, see Vol 3, Pt 1, Ch 5, 5.1 Plans and information 5.1.11. The evaluation process is to include the appraisal of a Risk Assessment (RA), in accordance with Vol 2, Pt 1, Ch 3, 18 Risk Assessment (RA), to verify that sufficient levels of redundancy and monitoring are incorporated in the propulsion and steering systems to support effective manoeuvring control of the ship during RAS operations.

7.3.1 The seakeeping and manoeuvrability characteristics of the ship are to be assessed and the requirements of the class notation LMA or LNMA in Vol 3, Pt 1, Ch 4 Manoeuvring Assessment are to be complied with as applicable.

7.3.2 The controls for propulsion arrangements are to be designed to allow for small accurate changes in propulsion speed which may typically be 0,2 knot/propeller speed ± 2 rpm.

7.3.3 The steering gear arrangements that provide a speed of rudder movement required in Vol 2, Pt 6, Ch 1, 4.1 General are to be recognised in the assessment of the ship's manoeuvring capability. The speed of rudder movement may require to be increased for ships intended for RAS operations that may typically be 35° to 30° opposite helm in 14 seconds with all the steering gear power actuating systems operating.

7.4.1 Arrangements for ship internal communications during RAS operations are to be provided. The communication equipment and systems are to be arranged to permit safe and effective communications throughout the RAS operations to all parties identified in the engineering and safety justification and the System Operational Concept.

7.4.2 As a minimum, means of effective ship internal communications are to be provided in accordance with Table 5.7.1 Internal communications. In addition, means of communications are to be provided for all those personnel involved with operation of equipment or movement of stores during RAS operations. For example, communications should be provided from the RAS station to:

1. The operators of fuel system valves, who need to be advised promptly of the completion of RAS operations so that the fuel system may be reconfigured for normal running (unless valve operation is by remote control from the Master Filling Control Station).

2. Those responsible for arranging for the supply and stowing the solid cargo who need to be appraised (quantity and type) of the stores en route and the completion of RAS operations.

3. The replenishment control office where provided.

The communication equipment and systems provided are to take into account the design of the ship (e.g. the Master Filling Control Station may be located on the Bridge) and the intended method of operating the ship during RAS operations.

7.4.3 The design of internal communications equipment and systems is to provide sufficient redundancy such that in the event of a single equipment failure, RAS operations can proceed safely.

7.4.4 Ship to ship communication protocols and standards are to be specified and agreed between the designer and Owner.

7.4.5 Arrangements are to be provided to allow the crew accurately to determine the distance between the ships during RAS operations (e.g. use a distance line) on a continuous basis. Guard rails or suitable alternatives are to be provided for the safety of personnel in exposed upper deck positions. The arrangements and operational procedures are to be such that the crew of neighbouring ships will not be exposed to RADHAZ.

7.4.6 Means of visual and aural communication between the ships conducting RAS operations is to be provided.

7.4.7 If distance lines and sound-powered communication equipment, as specified by the Owner, are to be passed between the ships that are to undertake RAS operations, the following criteria are to be complied with:

1. The positions of the communications equipment tie down/securing points and connections are to be agreed between the designer and Owner and shown on the RAS general arrangement plan.

2. Distance line securing points are to be clear of all RAS stations and positioned so the distance line is readily visible from the RAS officer's conning position. The exact locations for securing the distance lines are to be agreed between the designer and Owner and shown on the RAS general arrangement plan.

7.4.8 The communication system requirements between receiving ship, delivery ship and helicopter during VERTREP operations are to be specified by the Owner.

7.5.1  The power supplies to weapons systems are to be arranged to permit partial isolation in accordance with ship operation procedures (including RADHAZ) and orders relating to RAS operations.

7.5.2 Facilities are to be provided at each RAS station to permit electrical grounding of RAS equipment and stores. VERTREP stations are to be provided with facilities and equipment to permit the discharge of static electricity from the helicopter and/or its underslung cargo whilst airborne.

7.5.3 RAS systems are to be designed and installed such that they do not degrade from defined criteria (for equipment and the ship) stemming from susceptibility to magnetic interference sources that may include military activities. Systems are to comply with the technical requirements of IEC 60533: Electrical Installations in Ships, electromagnetic Compatibility. Emission limits and immunity requirements are to be specified by the Owner where those specified in IEC 60533 are not appropriate for the ship type.

7.5.4 Facilities and equipment to undertake RAS operations in darkness are to be specified. Typically this will require provision of low intensity red lighting at each RAS station and on the routes to/from the RAS station to the stores and within the stores to allow safe operations in darkness. The arrangements are to be agreed between the designer and Owner and included in the System Operational Concept. Provision is also to be made for suitable low intensity lighting at control panels for operating RAS equipment.