frnds i had a question in my mind...question is abt d rail electric engine.... in an electric engine there are 2 pantograph-> one in d front & one at d back... that touches the OHE(overhead electricity) which touches the wire above.... normally wen an engine is coming towards you ..you see dat the d pantograph which is at d back touches the OHE or the electric above the train...but sometimes some engines uses d frontside pantograph wen it's cuming towards us.... why is dat... can anyone clarify my doubt... i jst want to know why is it... bcoz i always get confuse why is it like this....???? plzz help me... to clarify my doubts....