'' hog engines food for environment ''
but need some more synchronisation since while train due speed & velocity able change tracks ., the pantogram change wire joints ., but for passengers '' chargers / lap top connection goes off and/or cabin a.c. goes down and/or pump / geyser in 1st a.c. do not work properly and water pressure reduces in toilets
for ''hog system'' ., some need based synchronisation required sir .
tks