There is still much debate in the safety literature about how to deal with the complexi- ties and dynamics of large-scale socio-technological systems especially. How, for in- stance, comes safety about in ‘high-tech’ complex systems? Also, how should assess- ments of technological (or artefactual) safety be performed in these kinds of systems? This thesis attempts to provide some practical applications and guidelines for these kinds of assessments, in real-life settings specifically. To this, four empirical studies of several high-tech military systems are discussed, and then how these studies were used for gaining a more adequate understanding of the dynamics of technological (or artefactual) safety in large-scale socio-technological systems in general. The thesis dis- cusses furthermore a study after the concept of responsible innovation, which is a field that closely relates to technological safety. This particular study points out that what was found for the assessment of technological safety could also be helpful for related allocations of responsibility in the systems studied here. An important factor appears to be in this all, that in practice the social and the technolo- gical (or artefactual) domain are linked in these kinds of systems to an extent that is not often acknowledged. Assessments of technological or artefactual safety in large-scale socio-technological systems, as well as allocations of responsibility in these kinds of systems, require, therefore, an empirical analysis of the socio-technological dynamics involved. These assessments and moral judgments should attempt, in short, to make sense of the empirical complexities in real-life settings. Important in this is that they should take into account – but also account for – the interactions between the tech- nologies (or artefacts) studied and the social structure(s) that these technologies (or artefacts) are embedded within.@en