USCG Homeport Marine Safety Alert: Recent failures of dynamic positioning (DP) systems on MODUs
- Safety Flash
- Published on 26 June 2013
- Generated on 29 January 2026
- IMCA SF 11/13
- 2 minute read
The United States Coast Guard has recently issued the Marine Safety Alert 05-13 about recent failures of dynamic positioning systems on mobile offshore drilling units.
Clarification has been sought on the following recommendations from the safety alert:
- Where ride-through capability is an essential part of the DP redundancy concept, it should be proven by live short circuit and ground fault testing.
- Perform regular thermal imaging surveys of DP system electrical equipment (e.g. switchgear, drives, motor controllers, etc.) as part of a preventative maintenance program to provide early detection of faulty or loose connections.
The response, which should be noted, was:
- Guidance does state that analysis and proper planning is required to undertake short circuit testing.
- The intent is to do this not at FAT, but on the vessel, with appropriate planning and safety precautions.
- Additional guidance is provided in the Marine Technology Society Techop guidance.
- One of the objectives is to have the test validate the model, so that subsequent testing can be done with analytical and modelling techniques based on a validated model.
- Any short circuit testing is to be accompanied by the proper planning and with appropriate risk mitigating measures in place.
The safety flash draws attention to the Marine Technology Society’s operational guidance which is available from the MTS dynamic positioning website www.dynamic-positioning.com. It should be noted that this guidance refers extensively to IMCA guidance.
We would also like to draw attention to the guidance contained within IMCA HSS031, M217 - Offshore vessel high voltage safety.
IMCA Safety Flashes summarise key safety matters and incidents, allowing lessons to be more easily learnt for the benefit of the entire offshore industry.
The effectiveness of the IMCA Safety Flash system depends on the industry sharing information and so avoiding repeat incidents. Incidents are classified according to IOGP's Life Saving Rules.
All information is anonymised or sanitised, as appropriate, and warnings for graphic content included where possible.
IMCA makes every effort to ensure both the accuracy and reliability of the information shared, but is not be liable for any guidance and/or recommendation and/or statement herein contained.
The information contained in this document does not fulfil or replace any individual's or Member's legal, regulatory or other duties or obligations in respect of their operations. Individuals and Members remain solely responsible for the safe, lawful and proper conduct of their operations.
Share your safety incidents with IMCA online. Sign-up to receive Safety Flashes straight to your email.