Section 1 General requirements

1.1.1 This Chapter states the requirements for ships having machinery redundancy, and are in addition to the relevant requirements in other relevant Sections of these Rules.

1.1.2 The requirements, which are optional, cover machinery arrangements and control systems necessary for ships which have propulsion and steering systems configured such that, in the event of a single failure of a system or item of active equipment, see Pt 5, Ch 22, 1.1 General 1.1.3, the ship will retain the ability to use available installed prime mover capacity and installed propulsion systems that are unaffected by the failure. The ship is also to retain steering capability at a service speed of not less than seven knots. The requirements also cover machinery arrangements where the propulsion and steering systems are installed in separate compartments such that, in the event of a loss of one compartment, the ship will retain availability of propulsion power and manoeuvring capability.

1.1.3 For the purpose of this Chapter, items of active equipment are those which have a defined function for operation of a propulsion or steering system, such as but not limited to:

• Prime movers, i.e. engines, electric motors, steam turbines and gas turbines;
• Generators and their excitation equipment;
• Transformers and converters;
• Gearing and shafting systems;
• Propulsion devices, i.e. propellers, water jets and thrusters;
• Pumps;
• Valves (where power actuated);
• Fuel treatment plant;
• Coolers/heaters;
• Filters;

Piping and electrical cables connecting items of active equipment are not considered to be active.

1.1.4 Requirements additional to these Rules may be imposed by the Flag State with whom the ship is registered and/or by the Administration within whose territorial jurisdiction the ship is intended to operate.

1.1.5  Pt 5, Ch 22, 2 Failure Mode and Effects Analysis (FMEA), Pt 5, Ch 22, 3 Machinery arrangements and Pt 5, Ch 22, 4 Control arrangements state the applicable requirements for arrangements necessary to maintain availability of propulsion and manoeuvring capability, in the event of a single failure in equipment. Ships complying with the applicable requirements of Pt 5, Ch 22, 2 Failure Mode and Effects Analysis (FMEA) to Pt 5, Ch 22, 4 Control arrangements will be eligible for the machinery class notation PMR or PMRL (Propulsion Machinery Redundancy), SMR or SMRL (Steering Machinery Redundancy) or PSMR or PSMRL (Propulsion and Steering Machinery Redundancy), which will be recorded in the Register Book.

1.1.6  Pt 5, Ch 22, 5 Separate machinery spaces * (star) Enhancement states the additional requirements necessary to maintain availability of propulsion and manoeuvring capability where machinery is installed in separate compartments and the loss of any one compartment due to fire or flooding has been addressed. Ships complying with the applicable requirements of Pt 5, Ch 22, 2 Failure Mode and Effects Analysis (FMEA) to Pt 5, Ch 22, 5 Separate machinery spaces * (star) Enhancement of this Chapter will be eligible for the machinery class notation PMR or PMRL (Propulsion Machinery Redundancy in separate machinery spaces), SMR or SMRL (Steering Machinery Redundancy in separate machinery spaces) or PSMR or PSMRL (Propulsion and Steering Machinery Redundancy in separate machinery spaces) which will be recorded in the Register Book.

1.1.7 For assignment of PSMR or PSMR machinery class notations, the ship is to retain the ability to use not less than 50 per cent of the installed prime mover capacity and not less than 50 per cent of the installed propulsion systems and retain steering capability at a service speed of not less than seven knots in the event of a single failure of a system or item of equipment.

1.1.8 Where the ship does not comply with 1.1.7 but can retain a service speed of not less than seven knots using available installed prime mover capacity and propulsion systems (which may be less than 50 per cent) following a failure of a system or item of equipment, machinery class notations PSMRL or PSMRL may be assigned. The available installed prime mover capacity and installed propulsion systems are to be identified and included in Pt 5, Ch 22, 1.2 Plans and information 1.2.7.

1.2.1 In addition to the plans and information required by Pt 5 Main and Auxiliary Machinery and Pt 6 Control, Electrical, Refrigeration and Fire, the information detailed in Pt 5, Ch 22, 1.2 Plans and information 1.2.2 to Pt 5, Ch 22, 1.2 Plans and information 1.2.6 is also to be submitted.

1.2.2  Machinery spaces. Plans showing the general arrangement of the machinery spaces, together with a description of the propulsion system, main and emergency electrical power supply systems and steering arrangements are to be submitted. The plans are to indicate segregation and access arrangements for machinery spaces and associated control rooms/stations.

1.2.3  Failure Mode and Effects Analysis (FMEA). For the propulsion systems, electrical power supplies, essential services, control systems and steering arrangements, a FMEA report is to be submitted and is to address the requirements identified in Pt 5, Ch 22, 2 Failure Mode and Effects Analysis (FMEA) and Pt 5, Ch 22, 5 Separate machinery spaces * (star) Enhancement.

1.2.4  Manoeuvring capability. An assessment of the ships' ahead and astern manoeuvring capability, under the following operating conditions, is to be submitted:

1. Where only 50 per cent or less of the installed prime mover capacity and 50 per cent or less of the installed propulsion systems are available.

2. Where the steering capability requirements described in Pt 5, Ch 22, 3.2 Steering machinery 3.2.1 are available.

IMO Resolution MSC 137(76) – Standards for Ship Manoeuvrability, provides guidance, on standard manoeuvres required in an assessment of the manoeuvrability of ships.

1.2.5  Testing and trials procedures. A schedule of testing and trials to demonstrate that the ship is capable of being operated with machinery functioning as described in Pt 5, Ch 22, 4.2 Bridge control is to be submitted. In addition, any testing programme that may be necessary to prove the conclusions of the FMEA is to be submitted.

1.2.6  Operating Manuals. Operating Manuals are to be submitted for information and provided on board. The manuals are to include the following information:

1. Particulars of machinery and control systems.

2. General description of systems for propulsion and steering.

3. Operating instructions for all machinery and control systems used for propulsion and steering.

4. Procedures for dealing with the situations identified in the FMEA report.

1.2.7  Installed prime mover capacity and installed propulsion systems. A schedule of the propulsion systems and their operating capacity and capability under normal and foreseeable failure conditions is to be submitted.