The accident progression in the capsizing of the oil platform Alexander L Kielland

21 January, 2022

As external specialists, Prof. Bevis Hutchinson and Joakim Hedegård from Swerim have reviewed documents presented in a new inquiry made by the Norwegian Office of the Auditor General into the capsizing of the offshore platform Alexander L Kielland in the North Sea.

The Alexander L Kielland disaster occurred just over 40 ago. A brace supporting one of the platform's five pontoon legs broke off one evening in hard weather and the leg was torn off. The platform listed quickly and turned over completely in just 20 minutes. 123 lives were lost in Norway's worst-ever industrial accident.

An official accident inquiry ensued immediately and, after a thorough investigation, the disaster was attributed to fatigue cracking in a weld, which led to one of the five support columns being lost.

To further clarify the causes leading up to the accident and how the authorities managed responsibility for the original investigation, the Norwegian Office of the Auditor General was tasked in 2019 by Stortinget, Norway's parliament, to conduct a new review of the investigation of the incident. With its expertise in metallography and the relation between factors such as mechanical properties and weld design and performance, Swerim was considered particularly qualified as an external specialist for the review.

"It has been very interesting and an honour to contribute to this important assignment," says Joakim Hedegård, joining technology specialist and examiner for the Swedish programme for International Welding Engineers (IWE). "We have worked with the accident in seminar form as part of the welding engineering programme for many years, so it has been very rewarding to have gained further in-depth knowledge of the incident and to have assisted with the inquiry.”

The work has resulted in a new, more easily accessible report concerning the accident progression. The conclusions are the same as those of the original inquiry, but the chain of events has been further clarified.