9 Group and Aggregation of Alerts and Indicators
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - International Codes - Code on Alerts and Indicators, 2009 - 9 Group and Aggregation of Alerts and Indicators

9 Group and Aggregation of Alerts and Indicators

  9.1 Grouping and aggregation should not conceal necessary information from the personnel responsible for the safe operation of the ship.

  9.2 Where audible and visual alerts and indicators are required at central positions, e.g., on the navigation bridge, in the machinery space, or engine control room; the alerts and indicators, except emergency alarms, should be arranged in groups, as far as practicable.

  9.3 The scope of alerts and indicators will vary with the type of ship and machinery. The basic recommendations given in tables 9.1 to 9.3 should be adhered to.

  9.4 Where visual alerts are grouped or aggregated in accordance with 3.10 and 3.11, individual visual alerts should be provided at the appropriate position to identify the specific alert condition.

  9.5 The purpose of grouping and aggregation is to achieve the following:

  • .1 In general, to reduce the variety in type and number of alerts and indicators so as to provide quick and unambiguous information to the personnel responsible for the safe operation of the ship.

  • .2 On the navigation bridge:

    • .1 to enable the officer on watch to devote full attention to the safe navigation of the ship;

    • .2 to readily identify any condition or abnormal situation requiring action to maintain the safe navigation of the ship; and

    • .3 to avoid distraction by alerts which require attention but have no direct influence on the safe navigation of the ship and which do not require immediate action to restore or maintain the safe navigation of the ship.

  • .3 In the machinery space/engine control room and at any machinery control station, to readily identify and locate any area of abnormal conditions (e.g., main propulsion machinery, steering gear, bilge level) and to enable the degree of urgency of remedial action to be assessed.

  • .4 In the engineers’ public rooms and in each of the engineers’ cabins on ships where the machinery space/engine control room is periodically unattended, to inform the engineer officer on watch of any alert situation which requires immediate presence in the machinery space/engine control room.

Table 9.1 Grouping/aggregation of alerts and indicators: machinery space attended, remote control of the main propulsion machinery from the navigation bridge not provided

Navigation bridgefootnote Machinery space
One common audible alert device, except emergency alarms (e.g., buzzer, continuous) Audible alert devices, in accordance with sections 5, 7 and 9
1 2 3
Workstation for navigating and manoeuvring on navigation bridge Other locations on navigation bridge Machinery space or control room/station
Individual visual alerts and indicators for: Visual alerts and indicators at any position on the navigation bridge other than the workstation for navigating and manoeuvring for: Visual alerts and indicators grouped at a position in the machinery space or, in the case of ships provided with a control room, in that control room. In complex machinery alarm arrangements, due account should be taken of 9.4.3
Each required steering gear:
- Power unit power failure
- Control system power failure
- Hydraulic fluid level alarm
- Running indication
- Alarm system failure alarm
Required alerts and indicators, as indicated under "Notes" in table 10.1.1 Alerts and indicators as indicated under "Notes" in table 10.1.2
Engine-room telegraph Any non-required alert or indicator which the Administration considers necessary for the officer on watch Engine-room telegraph
Rudder angle indicator Fire detection alarm  
Propeller speed/direction/pitch    
Telephone call    

Table 9.2 Grouping/aggregation of alerts and indicators: machinery space attended, remote control of the main propulsion machinery from the navigation bridge provided

Navigation bridgefootnote Machinery space
One common audible alert device, except emergency alerts (e.g., buzzer, continuous) Audible alert devices, in accordance with sections 3, 5 and 7
1 2 3
Workstation for navigating and manoeuvring on navigation bridge Other locations on navigation bridge Machinery space or control room/station
Individual visual alerts and indicators as in column 1 of table 9.1, plus: Visual alerts and indicators at any position on the navigation bridge other than the workstation for navigating and manoeuvring as in column 2 of table 9.1, plus: Visual Alerts and indicators as in column 3 of table 9.1, plus:
Failure of remote control for main propulsion machinery Machinery alarm, if provided Failure of remote control for main propulsion machinery
Starting air low pressure, when the engine can be started from the navigation bridge   Starting air low pressure
Propulsion control station in control   Propulsion control station in control
Indication of propulsion machinery orders from navigation bridge
Alerts and indicators as indicated under "Notes" in table 10.1.2

Table 9.3 Grouping/aggregation of alerts and indicators: machinery space unattended, remote control of the main propulsion machinery from the navigation bridge provided

Navigation bridgefootnote Machinery space Accommodation
One common audible alert device, except emergency alarms (e.g., buzzer, continuous) Audible alert devices, in accordance with sections 3, 5 and 7
1 2 3 4
Workstation for navigating and manoeuvring on navigation bridge Other locations on navigation bridge Machinery space or control room Engineers’ public spaces and accommodations
Individual visual alerts and indicators as in column 1 of tables 9.1 and 9.2, plus: Visual alerts and indicators at any position on the navigation bridge other than the workstation for navigating and manoeuvring as in column 2 of tables 9.1 and 9.2, plus: As in column 3 of tables 9.1 and 9.2, plus: Engineers’ alarm
Override of automatic propulsion shutdown, if provided Machinery space fire detection alarm Alerts as indicated under "Notes" in table 10.1.2 Machinery space fire detection alarm
  Alarm conditions requiring action by or the attention of the officer on watch on the navigation bridge Alert system power failure alarm Machinery alarm*
  Alerts and indicators as indicated under "Notes" in table 10.1.1 Steering gear alarm (common)*
    Machinery space bilge alarm*
    Alarm system power failure alarm
    Alerts and indicators under "Notes" in table 10.1.5
* Alarm may be common.

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