The Invisible Backbone: An Ethnography of Tiefbau Workers and Underground Infrastructure in Germany

This thesis examines how underground construction workers in Germany acquire, develop, and articulate embodied expertise within a context of persistent occupational stigma. Despite Germany's comprehensive vocational training system, strong labor protections, and the technical sophistication required for infrastructure work, construction labor remains socially devalued. While tacit knowledge, health and safety, and dirty work stigma have been studied, little is known about how underground construction workers connect their embodied expertise to mitigate the stigma. Drawing on contemporary short-term ethnographic fieldwork at a family-owned construction company in western Germany, this thesis investigates how workers utilize their embodied knowledge to navigate this paradox. The theoretical framework integrates body techniques (Crossley, 2007), carnal sociology (Wacquant, 2004), material engagement (Ingold, 2000), vocational education and training (VET) systems (Clarke et al., 2013), and dirty work (Ashforth & Kreiner, 1999). Empirical findings reveal that embodied expertise in construction emerges through: (1) repeated bodily engagement with materials, tools, and equipment, inseparable from their bodily history and personal experience, (2) a complementary relationship between formal vocational training and workplace learning, and (3) the strategic deployment of professional competence to counter dirty work stigma. This thesis concludes that workers derive a sense of empowerment and independence from this sophisticated knowledge to distance themselves from and resist external judgments.