The Rapid transit system in India consist of metro and monorail systems and Kolkata was the first city in India is introduce metro in 1984 and followed by the Chennai Mass Rapid Transit System then Delhi Metro. Delhi Metro is modern metro rail system which are now followed by all the metro cities of India such as Namma Metro Bangalore, Mumbai Metro,Hyderabad Metro and Rapid Metro Rail Gurgaon. Metro lines are combination of elevated, at-grade and underground travel system, Yellow Line of Delhi metro has the India’s longest underground metro tunnels of all lines. Here is the list of Operating and Under Construction and Upcoming longest tunnels in India.
The yellow line of Delhi metro is the second longest metro line among other rapid transit system in Delhi and connects Jahangirpuri in Delhi to HUDA City Centre in Gurgaon. The 45 km long line mostly underground and also known for Chawri Bazar station, deepest station of the Delhi Metro 98 ft below ground level. Yellow Line has longest metro tunnel in India with total length of around 30-35 km (Not Sure) with 34 metro stations.
The Delhi Airport Metro Express or DAME also known as Orange line linking the Indira Gandhi International Airport with Dwarka Sector 21. The 22.7 km long line has 15.7 km underground and 7 km elevated travel,Orange line has India’s second longest metro tunnel.
The Line 1 of Chennai Metro Rail project is one of the under construction metro line connecting Tiruvottiyur to Chennai International Airport. Chennai Metro Line 1 tunnel is the third longest metro tunnel in India with total length of 14.3 km underground tunnel travel system.
Line 2 and Line 3 of Chennai Metro will also have underground travel of length 9.7 km and 10 km respectively. The Phase I of the Chennai Metro rapid transit system project is expected to complete and operational by 2013.
The East-West Metro or Line 2 of Kolkata Metro will have 8.9 km underground and 5.77 km elevated travel connecting Kolkata with Howrah. Tuneel will have a underwater metro line over the Hooghly River and it will be the first underwater metro in India.
The Phase I of Namma Metro or Bangalore metro has two lines Purple Line and Green Line. Purple Lines has 4.88 km long underground tunnel and Green line has 4 km long tunnel equipped with all the latest technologies and system.