Indian Railways to roll out first batch of AC 3-tier economy coaches this month The production of the AC 3-tier economy class coaches began after successful oscillation trials conducted on the Nagda-Kota-Sawai Madhopur section at a speed of 180 kmph BusinessToday.In | March 3, 2021 | Updated 10:29 IST In the newly designed AC 3-tier economy class coaches, there will be individual AC vents for each berth, an ergonomically designed ladder for accessing the middle and upper berths, etc The Rail Coach Factory, Kapurthala has started manufacturing air-conditioned three-tier economy class coaches. According to a senior official, the coaches are capable of running at an optimum speed of 160 kilometres per hour.