The accident exposed critical safety flaws in North Sea commercial diving operations, contributing to improved bell design standards.
Key Facts
- Date
- 27 November 1978
- Deaths
- 2
- Bell depth
- Over 100 metres (330 ft)
- Time unrecovered
- Over 13 hours
- Age of victims
- Lothar Ward (25), Tony Prangley (28)
- Rescue vessels deployed
- 3 (Intersub 4, Tender Carrier, Uncle John)
By the Numbers
Location
Cause → Event → Consequence
During a routine dive beside the Beryl Alpha platform in the North Sea, the anchor chain of the semi-submersible Haakon Magnus severed the main lift wire, life support umbilical, and guide wires connecting the diving bell of MS Star Canopus to the surface, leaving the bell uncontrolled.
The diving bell plunged to the seabed at over 100 metres depth with two divers trapped inside. A design flaw — secondary locking pins securing the drop weight — prevented its release, and the absence of a bell stage meant the divers could not exit through the bottom door to free the pins manually.
Despite efforts by three rescue vessels over more than thirteen hours, the bell was not recovered in time. Both occupants, Lothar Ward and Tony Prangley, died of hypothermia and drowning. The accident highlighted serious deficiencies in diving bell safety design and emergency recovery procedures in the North Sea industry.