Controlling the London Underground power supply system under the Power Private Finance Initiative (PFI)

The London Underground currently comprises nearly 400 route kilometres and serves over 800 million passenger journeys each year. The control of the power supply system is carried out on a continuous basis by control room engineers and operators responsible for the safe and reliable supply of power for traction, signalling, lighting, station services, tunnel ventilation, and escalators. The power supply control system and the people who operate it are critical to the railway. Following a period of consultation to seek a future philosophy based on best current practice, Knights and Smith (1996) proposed a single power supply system SCADA solution that attempted to encompass the future organisational structure of London Underground Ltd. (LUL). This proposal allowed for separate central control of the high voltage network (22 kV and 11 kV distribution), and up to ten line-based control centres for the control of traction and small power to each railway line. On 16^th August 1998, The Power Private Finance Initiative (PFI) Contract commenced. 323 London Underground employees, including the author, transferred to SEEBOARD Powerlink (SPL), a company set up for the specific purpose of operation, maintenance and renewal of the power supply system. The contract is performance based so that SPL is required to provide electricity to reliability, quality and safety standards set and monitored by an LUL contract team. The article describes various aspects of the initiative including: operational philosophy; SCADA project; areas of responsibility; control room design; human machine interface; and management