External interference is the first cause of incidents on gas transmission pipelines in Europe in terms of frequency. The large majority of pipe breaks are indeed due to excavation works. Prevention barriers exist: slabs, warning tapes, surveillance patrols, public awareness campaigns, … but third party activities are gradually increasing and additional barriers are needed. Furthermore, incidents also occur on works contracted by gas companies themselves and specific barriers are missing for these particular situations. In this context, embedded systems for excavators can be interesting solutions to prevent the driver from hitting pipelines. However, studies conducted in the past have shown the limitations of such systems available on the market.
Thus, the CRIGEN (GDF SUEZ research center dedicated to gas and new energies) has worked on the specification of an embedded system, using an approach combining human factors and a functional analysis. This global method has been built to ensure that the potential solution will meet the need and that it will not have detrimental effects on the actual human organization which represents in itself a barrier.
This paper presents the main results of the work including the different methodologies and tools that have been used, but also the way they have been combined. The strong contribution of the human factors oriented analysis is detailed through: the identification of the hazardous situations to address, the identification of bias involved in incidents and the resulting safety functionalities for the system. Technical aspects of the method are also shown in the document, which includes a functional analysis and a benchmark of technologies of interest for the system. This allows a rather objective evaluation of several systems’ options combining different architectures and technologies. As a conclusion, a generic system architecture is proposed. This architecture mainly relies on existing tools and on a supervision unit. It is thought not to disturb the driver’s work but to help him digging in safer conditions by warning him in case of drift.