<Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (December 2009) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (December 2009) (Learn how and when to remove this template message) </Td> </Tr> <P> Sleipner A is a combined accommodations, production and processing offshore platform at the Sleipner East gas field in the Norwegian sector of the North Sea . It is a Condeep - type oil platform, built in Norway by the company Norwegian Contractors for Statoil . </P> <P> 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 and inaccurate finite element analysis modelling of the tricell, which formed part of the ballasting / flotation system . </P>

The sinking of the sleipner a offshore platform