The trains are expected to be back on track on December 10 though they will run, initially, at a maximum speed of 60 kmph until the cracks are ironed out. The official reason is that a goods train with defective wheels scraped off the surface of the Delhi-Ambala track on December 2.

Says Northern Railways General Manager S P Mehta: ``We have taken action against the goods train driver for driving a train with flat tyres.'' This, however, doesn't explain the fractures on the Delhi-Rohtak route. Whenasked, Mehta says that maybe another train with defective wheels was responsible for this.

Sources, however, say the reasons could be many: loose fishplates; hairline cracks caused by poor maintenance and in some cases, even old tracks damaged due to wear and tear. Says Mehta: ``At some place, the crack is wide and at others, the cracks are hairline. If the trains run faster on such tracks, there is a danger of derailment. We are repairing it through welding.''

The first crack was discovered near Panipat by an inspector on December 3 at 3.50 a.m., a week after the Sealdah Express-Frontier Mail accident at Khanna in which over 200 people were killed. The entire team of inspectors was asked to probe and all trains were directed to trundle at 30 kmph. By evening, 94 cracks were found.

Next day, the same team inspected rails on the Delhi-Rohtak route and found 67 cracks. A Railways spokesman says that ``heavy repair work,'' including welding, is on.

How will these cracks be prevented in the future? Whatkind of monitoring system is in place? Railways officials have no answers. Mehta, however, admits that some of the rails are quite old. ``But they have not yet crossed the expiry date. We are not replacing them. We are only filling the cracks through welding,'' he adds. And hoping for the best.