An explosive device that is akin to an anti-tank landmine, but just emits a loud sound, is partly responsible for your safe travel by train.
The Railways get detonators, which contain proprietary chemicals, from an ordnance factory specialising in explosives. These are flat, circular explosives or ‘pressure bombs’ that explode under the weight of a locomotive or a wagon wheel.
The Railways use these detonators sparingly — mostly to stop a train from chugging into a disaster. But when the explosives approach expiry, they are disposed of by surprising the personnel who must move a train from to its destination. “Each of these detonators has a shelf life of five years. We usually do not let the unused ones go waste and spring surprises on the running as well as station staff to test their alertness,” M.K. Agarwal, Principal Chief Safety Officer of Northeast Frontier Railway (NFR), told The Hindu .
The detonators, with metal clips, come in a box of 10 that the Ordnance Factory supplies to the Railways at ₹163. Each station is allotted two boxes and each gateman of a level crossing gets one.
The NFR, covering the northeastern States and parts of Bihar and West Bengal, has 369 stations and 1,504 level crossings. “We have to place the detonators when track damage or an obstacle is detected but the train is too close to stop by other means,” said Bhaskara Rao Baipalli, one of the three gatemen of level crossing NN274 on the western edge of Guwahati.
Emergency procedure
A gateman’s duty in such an emergency is to attach a detonator on a rail at 600m from the level crossing and three more detonators 10m apart till a distance of 1,200m. The driver has to apply the brakes after the detonators go off under the weight of the wheels. “The detonators are powerful enough for locomotive drivers to hear beyond the noise of the train. But they do not cause any damage to the railway line,” Mr. Agarwal said.
A detonator goes off under a pressure of 50-58 kg per sq. cm. by a wagon wheel. The weight a train wheel exerts on the track is seven tonnes while the axle load is 15 tonnes.
