It is known for its catastrophic failure on 23 August 1991, due to a design flaw, that resulted from an error caused by unconservative concrete codes[1] and inaccurate finite element analysis modelling of the tricell, which formed part of the ballasting/flotation system.
[5] The original hull was a gravity base made up of support pilings and concrete ballast chambers from which three or four shafts rise and upon which the deck sits.
[5] The post-accident investigation by SINTEF in Norway discovered that the root cause of the failure resulted from inaccurate NASTRAN calculations[7] in the design of the structure.
As the pressure increased, the walls failed and cracked, allowing sea water to enter the tank at an uncontrolled rate, eventually sinking the hull.
Computer-Aided Catastrophes, or CAC for short, such as the Sleipner Incident presented in this article, provide extremely valuable lessons for practising engineers working with numerical simulation tools such as the finite element method.
The reason for the poor finite element result that led to the Sleipner Incident have been studied in more detail in NAFEMS Benchmark Challenge Number 6.