An air bottle exploded in a lifeboat during an inspection of an uncrewed offshore platform, causing significant damage. The explosion was discovered while the platform was shut in, and no injuries or fatalities occurred since there were no personnel on board. The explosion caused one air bottle to propel upward into the lifeboat’s ceiling, another to fall into the sea, and one to remain intact. The lifeboat was later removed for further investigation, reports IMCA.
What happened
An air bottle exploded on a lifeboat causing significant damage. The damage was discovered during a periodic inspection of an offshore platform that had been shut in and had no crew on board. As the damage occurred on an uncrewed installation, there were no injuries or fatalities, but also no witnesses to the event or an exact date/time when it occurred.
The affected lifeboat was removed and taken ashore for further inspection. One of the bottles had exploded with a good portion of it propelling upward through the centreline seating structure and embedded itself into the overhead of the lifeboat. One bottle fell to the sea through the hole created in the hull of the boat and one bottle remained intact.
Why did it happen?
The operator coordinated with the lifeboat servicing vendor and local regulatory authorities to produce an understanding of the probable cause of the incident. The following points were noted:
- The bottles in this boat were purchased new in 2018;
- Further inspection after the lifeboat was brought onshore revealed significant corrosion over the length of the bottles in the area where they were in contact with the bottom of the boat.
- Each of the three bottles was placed in a form-fitting “saddle” built into the bottom structure of the lifeboat instead of being raised slightly above the deck in a cradle. The two brackets holding the bottles from above were made of stainless steel and there was no insulating material between this bracket and the steel bottles. It appears the installation and location of the bottles were subject to retaining moisture, especially between the bottle and the saddle. It could be that the corrosion was further exacerbated by galvanic action between the steel bottles and the uninsulated stainless steel bracket.
Members should be aware that this could affect any lifeboat with steel air cylinders installed in the same manner.
Lessons learned and recommendations
- The system ought to have been bled down after the platform was shut in and the crew was taken off;
- This particular installation provided very restricted access to these air bottles, so this greatly limited the ability to adequately inspect the bottles during regular weekly/monthly maintenance and annual servicing:
- The access ports only allowed a view of the top (valve end) of the bottle.
- The saddles in which the bottles rested completely obscured the section of the bottles inside the saddle.
- The bracket holding the bottles in place was of a different material and was in direct contact with the bottle (not insulated). Bleed down pressurized systems when no longer needed;
- Ensure pressurized air bottles are fully and adequately inspected during weekly/monthly maintenance and annual servicing;
- Look closely at how pressurized air bottles are stored – could there be moisture traps? Is there a way to avoid that?
- Ensure pressurized air bottles in lifeboats are raised above the deck to provide better ventilation around the bottle;
- Ensure any device holding pressurized air bottles in place is a similar material or suitably insulated between dissimilar materials – be aware of the risk of galvanic corrosion.
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Source: IMCA
