Transponder pressure relief system failure

  • Safety Flash
  • Published on 1 March 2005
  • Generated on 30 May 2025
  • 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:

Unintended Cargo collision during lifting operations
Read more
Person injured when unsecured grating gave away

A worker sustained discomfort to the right shoulder and abrasions to the left leg when the grating they stepped on gave way.

Read more
Electrical isolation: Failing to “prove dead” at the point of work

One of our members discovered that some personnel and worksites were not following the intent of their own company electrical isolation protocols.

Read more
Transport Malta: fatality after steel plates fell onto crew member

The Marine Safety Investigation Unit (MSIU) of Transport Malta has published Report 15/2024.

Read more
MSF: Multiple LTIs - Vessel gangway fell from quay causing injuries

The Marine Safety Forum has published Safety Alert 25-01.

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.