LTI: Worker lost his thumb

  • Safety Flash
  • Published on 28 April 2020
  • Generated on 23 June 2025
  • IMCA SF 14/20
  • 2 minute read

During drilling operations, a worker got his thumb caught under a part of a drill being lowered into position, resulting in the amputation of the thumb just above the knuckle

What happened?

The incident occurred during operations to retrieve core samples from the borehole. Our member notes that an Inner Barrel is deployed by freefall to latch into the Bottom Hole Assembly (BHA) of the drill string. The Inner Barrel was lifted into position by winch, attached to the Overshot, and lowered into the casing, ready to be deployed.

On this occasion, whilst deploying (de-latching) the Inner Barrel from the Overshot the assistant driller positioned his hands as shown in the photograph to depress the latch release keys.

As the Inner Barrel dropped under its own weight his left thumb was caught between the latching ring and the top of the casing resulting in the amputation of the thumb just above the knuckle.

The IP was taken to the nearest hospital. The medical team was unable to save the tip of his thumb.

Mock up of IP''s hand position at time of the incident
Lay key supporting the inner barrel

What went wrong?

  • Bypassing safety controls: the injured person failed to understand or use safety-critical equipment or follow procedures applicable to this task.
  • ‘Line of Fire’: the injured person got in the way of falling/moving objects.

What actions were taken?

  • Full review of all aspects of this task including revision of task work instruction and method statement.
  • Drill crews have been reminded to use the appropriate Lay Key intended for this task.

Members may wish to refer to:

Latest Safety Flashes:

NTSB: Vessel crane contact with shore-side crane

The National Transportation Safety Board of the United States (NTSB) has published a report and an investigation.

Read more
Dropped pallet during forklift operation

A pallet containing a load weighing 500kg dropped off a flatbed truck in close proximity to a delivery driver.

Read more
Dropped object hazard: access hatch to the communication dome

During a routine scheduled safety inspection of the main mast, it was discovered that the access hatch to one of the communication domes had fallen off.

Read more
Lock out/Tag out and unauthorised electrical connections/disconnections
Read more
MAIB: Is your Lead-Acid battery safe?

The UK Marine Accident Investigation Branch has published Safety Digest 1/2025, consisting of lessons from recent Marine Accident Reports.

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.