London Underground was the first, and is one of the busiest, passenger metro systems in the world. Since 1863, the network in, and under, the British capital has enabled London to become one of the preeminent world cities. It is estimated that 1.27 billion journeys are made yearly on the network, a figure projected to rise to 1.5 billion by 2023.
Regular maintenance is required to meet this demand and currently a renewals programme valued at approximately £2 billion is underway, as London Underground moves towards a 24-hour service. To help this happen, Clayton Equipment is in the process of converting 14 old Schoma diesel locomotives to Clayton Equipment CB40 specification battery-electric traction.