Transponder pressure relief system failure

  • Safety Flash
  • Published on 1 March 2005
  • Generated on 17 May 2026
  • IMCA SF 03/05
  • 1 minute read

Whilst reviewing its test and repair procedures for transponders, a member has reported that a serious flaw was discovered in the pressure relief mechanism in two out of three Kongsberg transponders tested. 

Such transponders are in common use across marine operations world-wide and it is possible that some could exhibit the same fault whereby internal pressure build-up would not be able to be vented automatically.

It appeared that the pressure relief mechanism was locked in place and would not operate, possibly due to an assembly fault by the manufacturer.

Pending detailed instructions from the manufacturer, the contractor instructed its personnel not to disassemble any such transponders.

Kongsberg has been exploring the matter, relating to the RPT model transponder (which went out of production in 2002) and has now issued a technical bulletin on the subject, a copy of which is attached below.

Safety Flash 03 05 3
Safety Flash 03 05 4
Safety Flash 03 05 5
Safety Flash 03 05 6

Latest Safety Flashes:

Worker suffered crush injury while handling unstable steel plates

Steel plates suddenly toppled over to the side trapping a worker's left hand and wrist between a frame and an emergency stop pedestal.

Read more
High Potential Near Miss: Dropped object due to contact with crane sheave

A Dynamic Positioning (DP) beacon came into contact with sheave protection bars, resulting in the beacon and its holder assembly detaching and falling to the deck below.

Read more
Machinery damaged through improper maintenance technique

During an audit on an offshore vessel it was observed that the fuel oil purifier failed to self-discharge.

Read more
Shifting cargo and deck spill during heavy weather

A sodium chloride brine storage tank shifted approximately 0.5m during heavy weather conditions.

Read more
MSF: Fast Rescue craft (FRC) washed overboard and lost at sea

The Marine Safety Forum (MSF) has published Safety Alert 26-03 relating to the loss of a Fast Rescue Craft (FRC).

Read more

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.