And here we worry about Amtrak trains waiting for freight trains! Here is a super fast rated express stuck waiting for higher priority expresses to overtake it. To mitigate this problem portions of this section are being triple and quadruple tracked progressively with installation of CTC and ERTMS II equivalent capabilities.
Dispatching that segment between Delhi and Kanpur is complex because there are at least five category of trains:
1. Priority Mail/Express
2. Other Mail/Express
3. Other Passenger
4. Priority Goods
5. Other Goods
Most of the route is double tracked with passing sidings at each station. Some of the planned triple tracking is in place already here and there. Eastbound every evening and Westbound every morning there is a stream of category 1 trains heading from/to Delhi to/from the East. To keep things moving on time, the dispatcher has to make sure that they have not released too many Goods trains so as to keep enough sidings free to place the category 2 and 3 trains into when the stream of category 1 trains come by. Once a category 2 or 3 train gets stuck in a siding they may be in it for a while as is illustrated in the video. When they are on time, such overtakes are scheduled into their timetable. A close study of the timetable gives a good indication where the overtakes are normally supposed to take place.
In this example 12303 is running behind schedule, and the parade of Priority 1s caught up with it before it could get to Ghaziabad.Ajaibpur, where this sequence is taken is the third or fourth station towards Kanpur/Kolkata from Ghaziabad Jn. where several lines come together to head from there into New Delhi and Delhi Jn. station over two separate routes. Normally 12303 is supposed to arrive into Ghaziabad and New Delhi before any of these trains that overtake it in this video are supposed to get there. So it basically gets held up for close to an hour while the on time flight of trains overtake it. This is why the adage "late trains get later" holds true in tightly scheduled segments with little additional capacity to play around with.
Here is the regularly scheduled overtakes that take place most late afternoons on the eastbound....
And lest you believe that Poorva Express only gets overtaken by others, here it is overtaking a lower priority express: