South Eastern Railway officials said the incident occurred around 3.52 AM when a local villager alerted the driver who applied the brakes immediately.
As the train was running at high speed, 22 coaches had passed over the fracture before the 24-coach train could be stopped.
Railwaymen from Kharagpur repaired the track and the train resumed its journey at 5.58 AM, they said, adding that no one was hurt.
According to sources, the crack prima facie appeared to be caused by a change in temperature, but inquiries are on to ascertain its exact cause.
"The police has been informed about the incident and they are looking into it," they said.
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