Near-miss: Diver’s umbilical severed by propeller
- Safety Flash
- Published on 1 March 2005
- Generated on 23 June 2025
- IMCA SF 03/05
- 2 minute read
A Member has reported a high potential near-miss which occurred during a regular field maintenance operation which was taking place from a lift boat in 7½ metres of water, whereby a diver’s umbilical was pulled into the lift boat’s propeller before it was completely severed with the diver less than 6 metres from the propeller.
The diver was working underwater on an offshore platform riser. The lift boat was stationed 6 metres from the work site and was elevated 60 cm from the surface of the water, leaving the propeller and rudder assembly underwater.
The configuration of the lift boat was such that the dive station was above the propeller area at the stern of the vessel. The dive crew’s standard procedure on this type of vessel was to secure the propeller driveshaft with a large pipe wrench, chain, binder, and lockout/tag-out. For unknown reasons, this procedure failed, causing the driveshaft to turn the propeller slowly, grabbing the divers hose and pulling the diver toward the propeller.
This action occurred very swiftly – in less than one minute over 20 metres of umbilical were drawn in, before it was completely severed. The diver surfaced unharmed.
Lessons learnt
Our Member has recommended that:
- A purpose-built clamp, which will not become disengaged, with padlock, must be installed on lift boat propeller driveshaft(s) prior to any diving operations.
- A lift boat must be elevated above the waterline enough to completely expose the propeller and rudder assembly.
- Specific job hazard/safety analysis must be performed, involving both vessel and dive crews.
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.