The past 15 years have seen an enormous shift in the regulation and management of infrastructure networks in the UK. Complex patchworks of competitive gas, electricity, water and telecom providers are replacing the relatively uniform, monopolistic and monolithic regimes of the post-war period. These changes have major, but poorly explored, implications for the economic, social and environmental development of British cities. In this context, the current paper aims critically to problematise the conventional approach of urban analysts to the development of urban technical networks. We do this in four parts. First, we develop a sympathetic critique of existing conceptual approaches to the study of urban technical networks. Secondly, we analyse the transformation of urban technical systems in the UK since the implementation of the Conservatives' privatisation process of the 1980s. In particular, we focus on the 'splintering' of infrastructure networks and the creation of complex new 'patchworks' of urban technical systems. Thirdly, we build upon this analysis to identify the social, economic and environmental logics emerging from this process of rapid change. Finally, we draw together the implications of the splintering process for the governance of British cities.