Bow thruster room flooded during fresh water transfer operation
- Safety Flash
- Published on 15 December 2017
- Generated on 12 July 2025
- IMCA SF 31/17
- 2 minute read
A vessel’s bow thruster room was flooded during fresh water transfer operations.
What happened?
The plan was to complete receiving fresh water in Tank No. 2 Centre first before moving to simultaneously fill Tank No. 1 Port & Tank No. 1 Starboard, while ensuring using soundings that neither tank was overfilled.
The Duty Motorman (about to end his shift) stopped receiving water into Tank No. 2 Centre believing that it had filled up, and transferred the supply to tanks No. 1 Port & Tank No. 1 Starboard as per the agreed plan.
The incoming Duty Engine Cadet sounded Tank No.2 Centre and realised that it was not yet full. This prompted him to stop and remove the transfer hose from Tank No.1 Port and returned the supply to Tank No.2 Centre. This tank had its sounding pipe linked to the bow thruster room.
Consequently, fresh water flooded the bow thruster room via the sounding pipe which was not locked, to the extent that the generator in the bow thruster room was submerged to about 2/3 of its height.
What went wrong?
- The sounding pipe of Tank No. 2 Centre was not closed (this was the sounding pipe linked to the bow thruster room).
- There was no adequate risk assessment of the fresh water transfer operation. There was no toolbox talk or discussion with the crew of the operation or the risks involved.
- The bilge emergency alarm was neglected by the Duty Engine Cadet.
- The emergency response plan was not followed during this incident.
What were the causes?
- Negligent watch-keeping practice
- Poor supervision of task
- Poor handover or shift change procedures
Lessons learnt
- Requirement for 24/7 watch-keeping in the engine room
- Better handling of shift change and handover processes
- Better supervision required particularly of trainee (Cadet) personnel
- Deeper crew understanding of emergency response safety drills particularly for bow thruster flooding
The Related Safety Flash below describes a very similar incident that occurred in July 2010; some “key issues” highlighted at that time included:
- failure of basic watch-keeping practices, and
- lack of understanding of Chief Engineer’s Standing Orders.
Related safety flashes
-
IMCA SF 05/10
28 July 2010
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.