Bikaner - kolkata - bikaner special ( pratap express)
Earlier this train runs with WDP loco between BKN & AF
There after E loco is coupled ......
Now jaipur - Agra route is electrified
So...
more... now this train also alloted with E loco from jaipur till kolkata
The same procedure can be accessed with
Bikaner - Howrah special
Jodhpur - Howrah special