Loose bolts on turbine engine exhaust stack
- Safety Flash
- Published on 1 May 1999
- Generated on 12 December 2024
- IMCA SF 03/99
- 1 minute read
The following near miss on an offshore installation has been reported.
What happened?
During high winds a 21m exhaust slack from one of the turbine engines on an offshore installation was seen to be moved abnormally. It appeared that the point of movement was at a joint halfway up the stack. Concerned that the top section might fall off, the installation was shut down and depressurised.
Our member’s investigation revealed the following:
When scaffolding was erected and lagging removed, all 64 bolts around the joint were found to be loose and many bolts had come off – this is assumed to be due to vibration. It transpired that this part of the stack installed ten years ago had not been inspected since, while other parts of the stack were included on the maintenance schedule. Also the bolts used were not the ones specified in the design. These have since been replaced with bolts with a locking nut to prevent them from loosening during service.
Recommendations
This near miss highlights the need for inaccessible joints to be included in planned maintenance routines.
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.