London Underground (LU) carries more than one billion passengers a year on a railway network which is 140 years old. With three and a half million journeys made each day, on 11 lines serving 270 stations the organisation must overcome many challenges each day to ensure a quality service. This presentation describes how London Underground ensures the availability of emergency lighting and smoke control ventilation fans within the transport network, detailing some of the challenges associated with them in a railway environment from an availability and maintenance perspective and techniques used to overcome them. The talk also covers the design considerations for safety systems, whether to go for CAPEX or OPEX and the pros and cons of each in the London Underground (and possibly the central section of Crossrail) environment.