MSF: dropped object inside vessel tank

  • Safety Flash
  • Published on 23 July 2026
  • Generated on 23 July 2026
  • IMCA SF 13/26
  • 2 minute read

The Marine Safety Forum (MSF) have published Safety Alert 26-05 relating to a tank cleaning machine coming lose and falling within a tank on a vessel.

What happened?

It is common for platform supply vessels to be equipped with fixed tank washing machines in some tanks. On one such PSV, such a machine was found on the tank bottom by the tank cleaning team. The washing machine, which weighed 10kg, had fallen from its fixed position due to a broken connection to the supply pipe. No-one was injured. 

What went wrong?

The following causes were identified during the investigation: 

  • Whilst periodic inspection and overhauling of these machines was addressed in the vessel Planned Maintenance System (PMS), the machines were very difficult to access, and as such, inspections had not been carried out properly.
  • These washing machines are mounted with threads and are not secured nor considered as Potential Dropped Objects.

Lessons learned

  • A careful check of the Potential Dropped Objects register – are there similar or other objects that could become DROPPED objects in different circumstances?
  • Consider secondary retention (e.g., safety wire, chain, or lanyard) between such washing machine and a fixed strong point on the tank structure.
  • What can be done about planned maintenance tasks that are really tricky, time-consuming or in difficult to access places? How do we make it easier to do things safely?

Latest Safety Flashes:

MAIB: Catastrophic engine failure and subsequent fire

MAIB has published Accident Investigation Report 10/2026 into a catastrophic failure of a diesel generator engine on board the vessel Kommandor Susan.

Read more
BSEE: Compressed gas cylinder hazards

BSEE has published Safety Alert 516, relating to potential risks involving compressed gas cylinders.

Read more
MSF: dropped object inside vessel tank

MSF have published Safety Alert 26-05 relating to a tank cleaning machine coming lose and falling within a tank on a vessel.

Read more
Uncontrolled movement of cargo

During offshore cargo operations alongside a rig, a single pipe loaded on deck shifted due to vessel motion and swell conditions.

Read more
Positives – rubber seals on hatches, securing of shackle pins, fuel sample box

A Member reports a few positive findings.

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.