The line runs seven hundred and forty kilometres down a coast that spent most of the twentieth century arguing about whether it could be built at all.
The engineering
Two thousand bridges and ninety-one tunnels, through laterite that holds a cut beautifully until the monsoon, at which point it does not.
The travelling
Nothing about the journey rewards planning. The best hour of it was an unscheduled halt outside Ratnagiri, waiting for a slope to be inspected, with the doors open and the rain coming in sideways.