Opened in 1863, the London Underground is the oldest and 5th largest metro network in the world with 402 km (250 mi) of tracks and 270 stations. To cope with incidents and accidents on the network, TfL (Transport for London) has its own emergency response units. They are based at Acton, Battersea and Camden and are operated by officers of the British Transport Police and London Underground engineers. The emergency response units are carrying heavy lifting and cutting gear for specific use in the Underground system and on the trains. The units are built in 2017 by John Dennis on a Volvo FL816 chassis. Seen here is Camden's emergency response unit.