WSH: Two workers passed out and died in a dredger's ballast tank

  • Safety Flash
  • Published on 22 July 2021
  • Generated on 30 August 2025
  • IMCA SF 20/21
  • 2 minute read

The Workplace Safety and Health Council of Singapore (WSH) reported in Accident Notification of 24 May 2021, that two workers had passed out and died in a dredger’s ballast tank.

What happened?

A supervisor entered a dredging vessel’s ballast tank, which is a confined space, for an inspection. The supervisor entered the tank without any appropriate Personal Protective Equipment (PPE) and did not check if the confined space was safe. Shortly after entering, he collapsed and passed out.

After some time, another worker entered the tank in an attempt to rescue the supervisor, but also passed out upon entry. A third worker attempted a rescue as well, but he too collapsed inside the tank.

The rest of the crew subsequently introduced forced ventilation into the tank. The second worker eventually regained consciousness and managed to climb out of the tank. The supervisor and the third worker were later extricated by the Singapore Civil Defence Force but unfortunately did not survive.  This tragic accident highlights the invisible dangers of confined spaces. 

Supervisor entered a dredging vessel’s ballast tank, which is a confined space, for an inspection

Recommendations

The WSH recommendations are:

  • Do not open up any manhole into a confined space without proper authorisation.

  • Do not enter any confined space unless you have had appropriate training.

  • Do not attempt any rescue on your own without proper PPE.

Members should review:

Latest Safety Flashes:

UK HSE: Motion Compensated Gangways Auto-Retraction

The UK Health and Safety Executive (HSE) has published Safety Notice ED03-2025

Read more
Brazil: diver permanently disabled after decompression illness

Conviction of diving company upheld as work accident suffered by a diver who lost strength in his upper limbs and the ability to move, requiring permanent use of a wheelchair.

Read more
Diver reports unwell post-dive: non-decompression illness

A diver experienced a dizzy spell about one hour after completing a diving operation

Read more
Shore-side crane boom collides with vessel mast

During shipyard lifting operations, the boom of a dock crane made contact with the vessel mast.

Read more
Injury sustained while operating steel lifting magnet

While preparing to transfer steel plates using a steel lifting magnet, a crew person was injured.

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.