What are pros and cons of third rail (railway electrification) system?I would like to also know its comparison with OCS (overhead catenary)

Expert Answers
kapokkid eNotes educator| Certified Educator

One of the main reasons for overhead catenary power systems for trains is to make it safe for pedestrians with the danger of an electrified third rail that pedestrians might touch or fall on.  One of the main arguments against this is simply that it can be unsightly and can also make maintenance more difficult.

There are new versions of the electrified rail system in which power is only available when the train is actually overhead which makes them safe in city streets or pedestrian-heavy areas, but these systems are not wide-spread.  The other disadvantage of the third rail system is that it is possible for the train to stop in a gap where no power is available along with some limitations on speed due to engineering constraints of the third rail systems.