IMCA M166 Rev.3 Explained
IMCA M166 Rev.3 provides guidance for carrying out Failure Modes and Effects Analysis on dynamic positioning systems. For vessel owners, operators and project teams, the purpose is not simply to produce a document, but to understand whether the DP system can tolerate defined failures without unacceptable loss of position capability.
A useful DP FMEA should identify the system boundaries, operating modes, redundancy concept, worst case failure design intent and the practical tests required to prove that the vessel behaves as expected.
Redundancy Verification
Verification that a single failure does not result in unacceptable loss of position capability. This includes power generation, distribution, thrusters, control systems, references, sensors and supporting auxiliaries.
Worst Case Failure
Identification and testing of the most severe single failure the DP system is designed to withstand. This is central to confirming the vessel's DP redundancy concept.
Power System Response
Assessment of generator, switchboard, protection, PMS and load sharing behaviour during fault conditions, including the effect on available thrust.
Thruster & Control Behaviour
Confirmation that thruster allocation, control logic and system reconfiguration behave correctly during simulated failures and degraded operating conditions.
Alarm & Operator Feedback
Verification that alarms, indications and operator information accurately reflect system status during abnormal or degraded conditions.
Common FMEA Findings
- System modifications not reflected in documentation
- Incorrect or outdated redundancy assumptions
- Unexpected interaction between DP and power systems
- Incomplete understanding of failure consequences
Ricketts Marine Consultancy provides independent DP FMEA and assurance support from Bergen, Norway, including document review, failure mode assessment, annual trial support and practical engineering input.
Discuss DP FMEA Support