Object falling from height
- Safety Flash
- Published on 30 November 2005
- Generated on 19 September 2025
- IMCA SF 11/05
- 1 minute read
IMCA has received a report of an incident wherein a ‘banana sheave’ roller weighing 4.5 kg came loose during operations.
What happened?
The roller fell some 24 metres from the derrick and hit the drill floor. Nobody was injured.
What were the causes?
The immediate cause of the accident was identified as being that the bolts which attached the rollers to the sheave had loosened.
The underlying causes were noted as:
- insufficient design
- insufficient maintenance
- lack of documentation and drawings describing that the sheaves should be function tested
- insufficient description of responsibility for involved personnel
- insufficient maintenance management and follow-up relating to lifting equipment.
Lessons learnt
The following points were noted:
- Lifting equipment should be examined and valid certificates for equipment in use should be presented.
- Inspection and maintenance should be performed on all sheaves that are in operation, with nuts and bolts inspected.
- All bolts on rollers should be fitted with protective pins to stop the bolt from loosening;
- The contractor’s planned maintenance management system in place should be reviewed accordingly.
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.