Automated display on the train. Lights on to show where it has yet to stop - important because the <> train does not stop at certain stations.

South Ferry station is the downtown terminus of the train. It is built on a very tight curve - you can only get out from the first few cars and they have these extending platforms to cover the gap. These three imaages show the platform extended - note two yellow strips and …

here is the platform retracted.

An hallmark of the New York subway is the lines of pillars close to the platform edge arising from they way they do cut-and-cover. This is Fulton Street station on the and lines.

An exception to the cut-and-cover construction had to be used at Washington Heights which include the highest natural point in Manhattan at 81 metres (265 feet) above sea level. So the platforms here at 181st Street station on the tunnelling construction was used. The line is reached by "three massive elevators" and and we have a wide space free of pillars.

Clearly the subway builders were not familiar with deep tube building techniques. There was a fatal accident during construction in 1903 and in 2009 an eight metre long section of the brick lining collapsed.

And even here, if we look in the opposite direction along the platform, they have reverted to their beloved pillars.

But by the time we get to Dyckman Street the subway has become overground.