Coming soon: Air train to run under planes on India’s only elevated taxiway at Delhi airport

NEW DELHI: Come 2028, aircraft taxiing on India's only elevated taxiway will have the country's only air train swishing on the road below them, along with vehicular traffic. TOI has accessed the route alignment of the proposed 7.7km automated people mover for which Delhi International Airport Ltd (DIAL) has issued a tender. To keep costs low, GMR Group-backed DIAL has not opted for an underground section connecting Terminal 2/3 on one side and T1 on the other, with the airport's backbone runway 28 between them.The air train's 7.7km routing will have almost 75% or 5.7km elevated portion and 2km at grade. The at-grade (surface level) section will be at two stretches — just before T1 and till crossing the main runway and then under the elevated taxiway. The rest will be all elevated, with a skywalk proposed at the cargo station to link it to the cargo terminal.DIAL is learnt to have steered clear of an underground section to prevent cost escalation. On average, the per km cost of elevated, at-grade, and underground metro lines in India is about Rs 250-300 crore; Rs 150-200 crore; and Rs 500-600 crore, respectively. This includes all costs, including the train, signal, electrical, and civil works, say people in the know.Rough estimates based on these figures suggest the air train could cost up to Rs 1,500-1,600 crore. The Union aviation ministry in Modi 2.0 had not allowed the airport operator to levy additional charges on passengers to fund the project and asked it to first build the same and then recover the cost.The operator has called for bids and will decide the winner on the basis of cost estimated by them and whether they offer revenue share (through advertising on this prime real estate that will grab the attention of lakhs of high purchasing power passengers) or seek viability gap funding.Air trains globally are free to use for passengers to ensure seamless transit between terminals. However, their cost is recovered through two means — aeronautical charges for airlines and user fees on passengers. The user fees charged at Mumbai Airport, for instance, used to have a metro component of Rs 20 and Rs 120 per domestic and international departure, respectively. This component was levied from 2016 to February 2023 to raise Rs 518 crore for metro connectivity and was stopped when that target sum was raised.Also, govt had asked DIAL to reduce the number of proposed stations from six to four to ensure expeditious intra-terminal transfers and foolproof security. Accordingly, the tender issued says the air train will have four stops — T2/3, T1, Aerocity and cargo city. The alignment shows three stations at Aerocity, which means subsequently, if allowed, the number of stops may be added on the air train.DIAL's air train tender document says: "DIAL proposes to implement an elevated cum at-grade APM system at Delhi Airport on a design, build, finance, operate and transfer (DBFOT) model. The APM system is intended to provide reliable, fast and seamless connectivity between T1 and T3/2 spanning a route length of around 7.7 km via Aerocity and Cargo city. In addition to providing required connectivity between terminals, the APM system will enhance passenger convenience, improve ASQ score and reduce carbon footprint."