Flag exchange is an interesting aspect to watch in Indian Railways especially when the train is not stopping but skipping the station. The loco pilot and assistant loco pilot both will wave the green flag as the station master and pointsman will acknowledge the flag exchange with their green flags standing on both side of the passing train. They will also watch the bogies of the coaches for hot axle and any other problem in the passing train and also the intact of formation. In the last coach, the gaurd will acknowledge with his green flag to the station master which ends the flag exchange process of the train. At night, it is green light
@Maersk.146 In this case, it is passing in 80 kmph as a speed restriction set due to track maintainance . Usually they maintain the max permissible speed if passing through the mainline