ABSTRACT Mumbai’s suburban railway network is one of the largest, most densely-packed public transport systems in the world. Known as the city’s ‘lifeline,’ these trains carry eight million commuters every day and provide crucial connectivity. Drawing on fieldwork at a railway carshed, this article uses infrastructural care as an analytic to ethnographically explore how practices of preventive and corrective maintenance not only repair trains but are also crucial in maintaining spatiotemporal flows produced by urban infrastructures. Repair and maintenance involve a distribution and convergence of human and nonhuman agencies that simultaneously reveals the ontological multiplicity of trains while also stabilising them as sociotechnical assemblages. In doing so, repair attempts to render faults knowable to predict and prevent failures, which then instantiates new routines across the traction rolling stock. However, carshed engineers also face bureaucratic pressures of ensuring both punctuality and safety, thus necessitating the managing of maintenance within increasingly saturated capacities.