Battery explosion during routine maintenance

  • Safety Flash
  • Published on 27 February 2023
  • Generated on 6 November 2025
  • IMCA SF 06/23
  • 2 minute read

A Chief Engineer suffered minor injuries in a battery explosion when disconnecting a cable from the battery.

What happened?

The incident occurred onboard a harbour tug.

The Chief Engineer was planning to replace a battery disconnect switch that had failed. While disconnecting the positive terminal, both terminals were inadvertently short-circuited with a spanner and the battery exploded, injuring the Chief Engineer.

Operations were stopped, first aid was given, and the tug returned alongside. After assessment at hospital the Chief Engineer returned to the tug with only minor injuries. The tug was out of service for four hours.

What went right?

  • The external power supply breaker was switched off.

  • To be able to work on the switch safely, it was decided to disconnect the battery cables so the switch would be isolated from the battery 24VDC.

What went wrong?

The battery was inadvertently short-circuited with a spanner.

Battery disconnect switch; switchboard; damaged switch

Lessons learned

  • Protect battery terminals with plastic caps to avoid accidental contact.

  • Ensure proper PPE (gloves, apron, face shield) is used when working on batteries.

  • Consider the use of tools appropriate for battery handling.

  • Changes to vessel's planned maintenance system:

    • Follow manufacturer's recommendations for battery maintenance.

    • Increase the frequency of battery maintenance inspection to gain better control of batteries in a poor state.

    • Consider the installation of battery chargers with temperature sensors.

Latest Safety Flashes:

Injury after fall from vertical ladder

Two crew members were performing routine engine room fire watch and thruster space rounds checking oil pressure and temperature checks, when one of them was injured falling off a vertical ladder.

Read more
LTI: serious injury to thumb when pipe fell during maintenance

A 2nd engineer on a vessel suffered a serious injury to the left thumb whilst dismantling a grey water pipe.

Read more
MSF: Burn to arm from contact with tumble dryer

The Marine Safety Forum (MSF) has published Safety Alert 25-13 relating to a crew member burning themselves on a tumble dryer.

Read more
Japan Transport Safety Board: two confined space fatalities

The Japan Transport Safety Board has published report MA2025-4 into a fatal incident which occurred in May 2024 on a bulk carrier.

Read more
On a more positive note…

A member reports a number of positive and encouraging trends following vessel visits across the fleet.

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.