RDSO/RB ne LHB trains ki length k hisaab se mps fix kiue hue h. For eg.
1. Bpl Shatabdi ka mps 160 nhi kiya gya kyoki usme 18 coaches h jbki Gatiman me sirf 12 h.
2. Mumbai Rajdhani jb 20 coach ki thi tb uska mps Mtj-ndls section me 140 tha lekin jb se 22 coach ki hui h mps 130 h.
3...
more... MGS-NDLS k bich chlne wali sbhi sleeper SF jinka mps 130 h un sb ki length 22 coach ki h, jbki un saari trains me kaafi bheed hoti h fir bhi unko extra coaches nhi milte.
4. Ndls-Bpl k bich bhi koi LHB sleeper coach wali train nhi h jiska MPS 120 se upar ho.
Esa RB/RDSO ne shyd couplings ki wjh se kiya h. Long rake me higher speed pe coupling khulne ka risk rhta h shyd. This is just my assumption actuall reason to Mujhe nhi pta h bss itna pta h ki only 22 coach lhb rake is allowed to go till 130.