HWH - Dankuni is 100/110 only.
Dankuni - Dhanbad - Gaya - MGS is 130 kph
Distance between Dankuni - MGS via Dhanbad is 648 km/s, time take 7 hr 40 mins by Rajdhani n Yuva. avg 80 kph
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NGP...
more... - SC is 575 km/s.
Fastest train is SBC Rajdhani which takes 8 hrs 10 mins avg speed is around avg 70 kph only.
And in some sections its 110 too!!
SC - KZJ is still a mystery for now, but many rf's have said its upgraded to 120-130, but from KZJ - NGP, its 120 for SC Raj.