High potential dropped object – chains

  • Safety Flash
  • Published on 26 February 2020
  • Generated on 26 July 2026
  • IMCA SF 07/20
  • 2 minute read

A set of heavy chain links, or ‘Brothers’ used in lifting, fell from a turbine tower onto the front deck of a Crew Transfer Vehicle (CTV) below

What happened?

The incident occurred when loads were being lifted to the transition piece level of an offshore wind turbine tower using a davit crane.

After lifting two loads, the crane operator released the three hooks on the lifting bags and raised the crane hook up using the hand pendant while another crewman started to manually operate the crank handle to slew the crane hook towards the CTV, ready to lift the third load.

Instead of raising the crane hook and attaching ‘Brothers’ above the height of the transition piece gate handrail, the crewman raised the hook approximately 50 mm above the transition piece gate handrail and once the crane hook was nearly slewed to the gate, stopped the lifting operation and manually re-position the set of ‘Brothers’ over the handrail before continuing lifting operations by lowering the load while slewing continued. 

The practice of manually repositioning the ‘Brothers’ was intended to make the lifting operations slightly quicker; however, it resulted in the bottom handle of the crane hook impacting on the top of the transition piece gate handrail, making the crane hook open and the crane hook itself tilted.

This then resulted in the set of ‘Brothers’ falling onto the front deck of the CTV below. There were no injuries.

What went wrong?

A set of heavy chain links, or ‘Brothers’ used in lifting, fell from a turbine tower onto the front deck of a Crew Transfer Vehicle (CTV) below

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.