Failure of underwater pan and tilt rotator unit
- Safety Flash
- Published on 8 May 2015
- Generated on 24 July 2026
- IMCA SF 06/15
- 2 minute read
A Member has reported an incident in which there was a small explosion and fire on a remotely operated vehicle (ROV).
What happened?
Personnel had reported having experienced minor issues with the upper pan and tilt unit fitted on the ROV camera whilst it was subsea. Once the unit was recovered, they intended to connect it to a computer and run the on-deck camera analyser software.
An explosion blew the single axis driver assembly (SADA) with the camera unit attached (approximately 5kg weight) away from the main rotator unit. The explosion resulted in the SADA with camera becoming separated (the 6 x 5mm grommet screws connecting the SADA to the camera pan and tilt main housing were sheared) and propelled at a high speed away from the pan and tilt main housing. Flames were noticed coming out of pan and tilt rotator unit and extinguished.
There were no injuries.
Close up of pan and tilt unit
Broken pan and tilt unit shown in situ
Close up of broken pan and tilt unit
Our member noted that the origin of the over-pressure that led to the explosion is still unknown and under investigation with the unit manufacturer.
The following lessons were learnt:
- Never be in the line of fire.
- Maintenance/repair work on the pan and tilt units should be reduced to ALARP – as low as reasonably practical.
- Ensure there is a robust management of change process – ensure that there is proper risk assessment when the situation has changed, as in this case.
Related Safety Flashes
-
IMCA SF 08/03
3 July 2003
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.