For RailFans, seeing RAC-1/2/3 in Mumbai-UP Trains is more exciting than Election Results - rdb

mountainous terrain. on flat plains it wouldn't cost much to upgrade, but here you have to literally move mountains to achieve 130 Kmph. for many trunk routes in India, the section passing through MP is the bottleneck, courtesy the plentiful mountains in that state. also, even on those tracks where 130 exists, banking is an issue. tighter curve can be done with more banking of line, but that causes discomfort to passengers. no banking leas to very high radius of curvature, so somewhere a compromise will be needed. long story short, the route out of mumbai is going to be a nightmare to upgrade to 160. you need to eliminate LC's, eliminate many banked sections of the track (there are bucket loads of them), literally move mountains in RTM-GDA stretch and upgarde the OHE to tolerate 160 Kmph (the reason for which talgo trials were done by WDP 4)

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