Catenary

Oh yes, I just have to show off that word - it means "the curve assumed by a cord of uniform density and cross section that is perfectly flexible but not capable of being stretched and that hangs freely from two fixed points". Apparently, the definition for that kind of a curve has also been adapted to describe the Overhead Line Equipment (OHLE) that is used to power trains running on electricity - as the ones on Chennai's suburban lines are.

This is a stretch of the railway tracks just across the road from the airport; it is a rather straight stretch, which is fairly common on the Tambaram - Beach line. The catenaries are hung out from points on the crossbar; the whole arrangement looked like a series of goal posts - was tempted to show them all receeding into the distance, fitting inside each other, but it didn't seem like a good idea to stand in between the tracks trying to get a 'perfect picture', so I just settled for this one.

There was something I noticed then, something that continues to intrigue me: what are those rolls of - wire mesh? I mean the green things tucked inside the crossbar, on its left. It can be seen in every one of the crossbars. Does anyone have any idea what that is for?