to my knowledge Tpty-MTM/NS exp has Electric till BZa from there Single alco till GDV after Gdv one alco will take to NS and anther alco to MTM.
In return two spe alcos till GDV for MTM-Tpty and Ns-Tpty exp from Gdv one alco at front end some times and one at rear end or only one alco tilll BZA other alco will rest at GDV only.