DP Mini Guide: Gyro — Heading Reference Failure

Crew Connect DP Academy · Mini Guide 05

Gyro — Heading Reference Failure

Topic: Sensors · Sub-topic: Heading Sensors  ·  Level: DPO  ·  Read time: 8 min

1. What / Why / How

Heading input feeds directly into thrust allocation — the DP system needs to know which way the vessel is pointing to work out how to apply thrust correctly. Gyros are typically selected/voted between multiple units, and that selection logic matters as much as any individual gyro's health.

2. Recognition / Risk / But

Watch for: a gyro alarm, static divergence between units, a trend mismatch, an unexpected change in which sensor is selected, or an unexpected thrust response with no obvious external cause.

But: two gyros that appear to agree can still share a ready-signal, power distribution, or configuration fault — agreement between two units isn't proof of independent health.

3. Now / What next / Decision / Why

Verify which sensors are actually selected and available, identify which redundancy group is affected and how the system has responded, review your applicable operating status, and notify the operation as required by your procedures.

4. Consequence / Reassess / Escalate

An isolated single-gyro disagreement can develop into loss of two inputs through a shared connection. When that happens, re-evaluate your Worst Case Failure assumption and the current activity's status — don't treat the second loss as an unrelated, separate event.

5. Recover / Verify / Human factor

Reinstatement of a faulted gyro must include the approved checks and a credible independent comparison, not just a quiet readout. Trap: accepting a known historic offset because "the system has always run like that" — familiarity isn't the same as a verified, understood fault.

Sources: IMO MSC.1/Circ.1580 (sensor requirements), IMCA M252, IMCA DPE 03/20 (gyro loss/common-mode learning), IMCA M166 Rev.3 & M190 Rev.3.2 (FMEA/trials context). This guide is educational content, not a substitute for accredited DP training, vessel-specific FMEA/ASOG, or full-mission simulator assessment. Crew Connect never infers compliance with a specific vessel's applicable requirements — always verify against your own approved documents.