11.1.1 Adequate back-up arrangements should be
provided to ensure safe navigation in case of a failure within the
INS.
11.1.1.1 In case of failure of one part
or function of the INS, including network failures, it should
be possible to operate each other individual part or function
separately; at least the requirements specified for individual
equipment adopted by the Organization should be met, as far as applicable.
11.1.1.2 The back-up arrangement should enable
a safe take-over of the INS functions and ensure that an
INS failure does not result in a critical situation.
11.1.2 The failure of a single task station should
not result in the loss of a function mandated by the carriage requirements
of SOLAS.
11.1.3 In case of a breakdown of one task
station, at least one task station should be able to take over
the tasks.
11.1.4 The failure or loss of one hardware component
of the INS should not result in the loss of any one of the INS tasks:
- Route planning
- Route monitoring
- Collision avoidance
- Navigation control data
- Status and data display
- Alert management
Where track control is an INS function, this would not require
the duplication of heading control or autopilot.
11.1.5 The INS should allow that the back-up component
automatically (if possible) takes over the operation of the primary
component.