Uncontrolled ascent of lay-down head
- Safety Flash
- Published on 1 March 2005
- Generated on 20 April 2025
- IMCA SF 03/05
- 2 minute read
A Member has reported that a saturation diver in 120 m of water, preparing to move a pipeline lay-down head (LDH) using a lift bag, was struck in the back by the uncontrolled ascent of the LDH.
The LDH was being used as a deadman anchor to assist in aligning a pipeline.
What were the causes?
The resulting investigation concluded that:
- The lift bag affixed to the LDH had a higher rating than the load to be lifted – inaccurate use of LDH weight data provided in the procedure while making a field change.
- There had been inadequate communication – offshore personnel had not been appraised regarding the LDH’s true weight.
- There were inadequate guards/protective devices – due to the distances involved in moving the LDH, the lift bag dump line and safety strap were not connected.
- There had been inadequate assessment of the level of change – the task had been carried out under a ‘minor’ management of change (MOC) procedure.
Lessons learnt
Our Member recommends that:
- Diving operations using lift bags should always follow the company’s guidelines.
- Anchors should have a known measured weight or have their weight calculated for the condition of use.
- Lift plans should include the weights, weight calculations and methods of those calculations.
- The deletion of a dump valve’s safety line constitutes a significant change, requiring the use of an appropriate MOC procedure.
- When a safety device is disabled or a safe procedure is bypassed, a task must be further risk-assessed, brought to a higher level and fully documented; this is true even in situations where a safety device might increase the risk of incident or injury.
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.