After the successful haulage of train number 22221/22222 Mumbai CSMT CSMT-Nizamuddin Rajdhani Express by twin locos (one loco in front, and one loco in rear) in push-pull mode, IR has proposed to extend this to other Rajdhanis as well.
The reason cited being higher average speeds due to faster acceleration and deceleration of the push-pull configuration
While this is commendable for these prestigious trains, the Indian Railways should pause a while and consider whether these may actually be the wrong class of trains which are being prioritized for this format.
Rajdhanis get the maximum priority over other trains along their path besides having a minimum number of halts.
This means that a Rajdhani is able to run most of the time at the maximum permissible speeds without frequent acceleration/deceleration
Hence the push-pull configuration is less beneficial to Rajdhanis than those trains which halt at say every 40 odd kilometres on an average and is hauled end-to-end by an electric loco.
A classic example of this is the Howrah Delhi Kalka Mail which travels 1712 km with 37 intermediate halts (average halt distance is 46.2 km).
Hence, such trains with a larger number of halts or path issues should get priority in getting the push-pull haulage format.
Also if Indian Railways wishes to achieve higher average speeds for trains running in fully unelectrified territory, they might use the push-pull mode using 2 Diesel locos.
However, the push-pull format is not feasible for trains which run in both electrified and unelectrified territory from origin to destination.
In addition, the short and medium distance intercity and mail/express trains also need a higher degree of punctuality due to a large number of commuters travelling in such trains.
For this, Indian Railways may re-configure the WAP-4 locos making them fit for push-pull working.
This could be done in addition to IR’s decision to ramp up production of three-phase locos.
Push-pull is also beneficial for increasing the average speeds in sections where the maximum permissible speeds cannot be increased due to constraints such as lack of availability of land, funds and technology.
Most sections on IR are not fenced, yards at major stations still pose path and speed challenges due to congestion, sharp turnouts and dilapidated cement concrete aprons.
Moreover, there are numerous permanent and temporary speed restrictions along a train’s path which hampers average speed.
In sum, push-pull is extremely beneficial, for all fully electric hauled mail/exp/SF/Intercity trains.
Image credit: Amol Nikam