The Diamond Quadrilateral is a project of the Indian railways to establish high speed rail network in India. This quadrilateral will connect the four metro cities in India, i.e. Delhi, Mumbai, Kolkata and Chennai. This project is similar to Golden Quadrilateral which is a roadway project which connects the four metros by Express Ways. The Golden Quadrilateral falls under National Highways Development Project which has helped to build better road transport in India. Similarly to improve country's rail infrastructure there is a need to implement High-speed trains / Bullet trains. So to fulfill this demand the Diamond Quadrilateral project was planned. India today is planning to start Semi-high speed trains on nine corridors and has ambition to run bullet trains in future. High-speed train on Mumbai-Ahmedabad section will be the first bullet train corridor to be implemented in the country. On 9 June 2014, the President of India Pranab Mukherjee, officially mentioned that the Government led by Prime Minister Narendra Modi will launch a Diamond Quadrilateral project of high speed trains.
India is a unique country amongst major countries not to have high speed rail corridor capable of running trains over 250 km/h.
India plans to develop high speed rail network in two phases. In the first phase, segregated rail corridors will be upgraded using conventional technology to train speeds of 160 to 200 km/h. In the second phase, key intercity corridors will be identified and state of the art high speed corridors will be developed upto 350 km/h using public private partnership and state ownership. The objective is to develop at least 4 corridors of 2000 km by 2020 and have at least 8 other corridors in different stages of progress.
This corridor will be operated on standard gauge. The major terminals will be at Delhi, Mumbai, Pune, Visakhapatnam, Thiruvananthapuram, Bangalore, Chennai, Hyderabad and Kolkata. The corridor will pass through 14 states and territories in India. These states are Gujarat, Andhra Pradesh, Bihar, Haryana, Jharkhand, Maharashtra, Karnataka, Kerala, Odisha, Rajasthan, Tamil Nadu, Telangana, Uttar Pradesh and West Bengal. Trains will operate at top speed of 320 kmph and average speed of 250 kmph.
All the six corridors will have follwing stations:
Delhi - Kolkata corridor : New Delhi - Aligarh - Agra - Kanpur - Lukhnow - Sultanpur - Varanasi - Buxar - Gaya - Patna - Dhanbad - Asansol - Bardwan - Kolkata
Delhi - Mumbai corridor : New Delhi - Gurugram - Rewari - Jaipur - Ajmer - Bhilwara - Udaipur - Himmatnagar - Ahmedabad - Anand - Vadodra - Surat - Vapi - Boisar - Virar - Thane - Mumbai
Mumbai - Chennai corridor : Thane - Navi Mumbai - Lonavala - Pune - Kolhapur - Belagavi - Hubballi - Davangere - Tumkur - Bangaluru - Banagarpet - Chennai
Kolkata - Chennai corridor : Kolkata - Haldia - Cutttack - Bhubaneshwar - Vijayanagram - Vishakapatnam - Rajahmundry - Nellore - Chennai
Delhi - Chennai corridor : New Delhi - Agra - Gwalior - Guna - Bhopal - Itarsi - Betul - Nagpur - Nizamabad - Hyderabad - Vijaywada - Ongole - Chennai
Mumbai - Kolkata corridor : Thane - Nashik - Aurangabad - Akola - Nagpur - Durg - Raipur - Bilaspur - Rourkela - Kharagpur - Kolkata
Contracts have been awarded to carry out the feasibility study of high speed rail corridors. The corridors being considered for feasibility study are as follows,
- Package 1: Delhi Mumbai - Feasibility Study Contract awarded to a Consortium of M/s The Third Railway Survey and Design Institute Group Corporation (CHINA) and Lahmeyer International (India) Pvt. Ltd, India
- Package 2: Mumbai Chennai - Feasibility Study Contract awarded to a Consortium of M/s SYSTRA (FRANCE) - RITES- Ernest &Young LLP
- Package 3: Delhi Kolkata - Feasibility Study Contract awarded to a Consortium of M/s INECO (SPAIN) - M/s TYPSA- M/s Intercontinental Consultants and Technocrats Private Limited
Expected cost of 1583 km Delhi - Kolkata corridor is around ₨ 84000 crores and is capable of reducing the travel time to just over 5 hrs from existing 17 hrs taken by Rajdhani.
Apart from these projects, ongoing projects include the following,
- Delhi-Chandigarh-Amritsar - Pre-Feasibility study of this High Speed Rail Corridor is in progress. Interim Report-II has been submitted by the consultant M/s Systra of France in Sep 2015.
- Chennai-Bangaluru-Mysore - Feasibility Study for Speed raising on this section in cooperation with China Railway Eryuan Engineering Group is in progress. China Railway Eryuan Engineering Group has submitted Interim Report in June 2015. High Speed Rail Corporation of India Ltd is the counterpart agency
The Ministry of Railways stated that the final feasibility reports for three high speed rail lines — from Mumbai to Chennai, Delhi and Nagpur - would be completed by January 2017. Preliminary geo-technical studies, and other related studies, are expected to begin by 2018.