New Guidance on the Design of Offshore Structures to Resist the Explosion Hazard

In 1992 Interim Guidance Notes were issued in the UK to provide guidance for the design of offshore topsides for fires and explosions. This Guidance was one consequence of the Piper Alpha Tragedy in the North Sea. Since 1992 a great deal of further research and technology has been developed in order to improve understanding of the characteristics of fires and explosions and the response of the structures and equipment to these events. In order to collate this new information in a readily useable format, the United Kingdom Offshore Operators Association (UKOOA) and the Health and Safety Executive (HSE) commissioned the MSL Consortium to update the existing Interim Guidance Notes and produce Part 1 of the new Guidance. The MSL Consortium consisted of the organisations represented by the authors with contributions from WS Atkins (Houston) and Beth Morgan Safety Solutions. The project manager was Minaz Lalani of MSL. The new Guidance is being developed in three parts. The first two parts deal with the philosophy for the avoidance and mitigation of explosions and fires respectively, which together establish the background for Part 3 which will provide detailed guidance on design practices for fire and explosion engineering. This paper describes the first document. Specific issues which are discussed include installation risk screening, nominal explosion loads, inherently safer design, hazard management, and the derivation of Design Explosion loads. This paper also describes the recommended method for explosion response assessment given in the Guidance.