DDC chamber viewport catastrophic failure
- Safety Flash
- Published on 19 March 2008
- Generated on 17 June 2025
- IMCA SF 04/08
- 2 minute read
IMCA has received the attached safety alert from the Association of Diving Contractors International (ADCI).
DDC chamber viewport catastrophic failure
This viewport was in a deck chamber where someone had placed droplight too close to the port. The resulting radiant heat from the lamp exceeded the design temperature of the view-port (125 deg. F / 51.6 deg. C). Enough heat was generated to allow the view-port to become soft and pliable enough to allow the pressure in the chamber to flow towards atmospheric pressure. (See pictures attached.)
The pressure boundary was breached and the chamber vented through the view-port to atmospheric pressure. No further information on this incident is available. The danger of incandescent light bulbs in close proximity to chamber ports is well known in the diving industry. To mitigate this danger, many diving contractors have changed to the fluorescent bulb drop lights, with the understanding that they operate at a lower temperature.
WE HAVE NOW DETERMINED THAT FLUORESCENT LAMPS CAN ALSO GENERATE HEAT IN EXCESS OF 140 DEGREES! Do not put drop lights in contact with chamber view-ports, even fluorescent drop lights can generate enough heat to cause the view-ports to overheat.
You must always assess the heat generated from any bulb and make sure you position the bulb a sufficient distance away from the port to eliminate the possibility of any heat build-up on the face of the port. If the port feels warm to the touch, the bulb is too close!!
Click here for more details.
Amended 1/8/23
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.