DC Line - ये आग का दरिया पार कर पाना नहीं था आसान ...पर धनबादवासियों के इरादे हैं चट्टान.... चलाकर रहेंगे इसपर रेल गाड़ी महान... - Niket Karan

Now let me tell u the operating reason apart from these why coaches cant simply be coupled /decoupled right in the middle of the journey.. Let for our case assume that the stn choosen for attach/detach in HBC chordline is BRPA approx 24 km from HWH & 71 km frm BWN.let say a 15 coach train starts it journey at 7.10 frm HWH crosses DKAE at 7.29, JNX at 7.34 to reach BRPA at 7.41. In this process it overtakes a freight at DKAE & JNX which waited for 19 mts each at respective stns to get overtaken & commence their journey at 7.37 & 7.44 respextively. Our Exp after addition of Slip coaches restarts its operation at 8.05 frm BRPA but by the mean time both the freights have moven further forward & again they need to be looped at CDAE at 8.17 & BMAE 8.23 for reovertake by the...
more...

same Exp. So this is nothing but killing precious time of other trains. So u can see even though the slip coach attachment /shunting going on in the yard & doesnt affect anything on the mainline still the running in mainline is hampered justt because the train waited an extra time in the yard. This is prexisely the case with ur pythons also.. Apply the same logicslightly change the factors & you can understand how coupling/decoupling is for a long run not useful for a section & doesnt solve any purpose regarding operating point of view. Regarding commecial viewpoint they obviously solve a huge purpose. Just like our 15 coach imaginary train it has such mad rush that pax wont mind if they get berths from 26 km advance locn, tkt sales would rise & provide extra revenue to Rlys. Because commercialy it is always viable to run one 24 coach train than running two trains one with 15.other with 9 coaches. But the operating norms will simply dont allow such thing to happen.