That’s, obviously, the newly reopened Cortlandt Street Station on the 1 train. The station was badly damaged on 9-11 and the story as generally told is that it was rebuilt. That’s true as far as it goes, but leaves out some interesting details. The station is on the south end of the line, two stations from the terminal at South Ferry. It was obvious that the station would not be reopening for years – not only was it a shambles, it was surrounded by the foundation-pit-full-of-debris that was the World Trade Center in late 2001 – but closing the stations to the south would have been a huge problem for commuters. The MTA’s solution was to rebuild the tunnel roof structure only, to allow trains to pass through the site safely, and worry about the station later. Later turned out to be the mid-2010s.
“Rebuild quickly” was an interesting problem. Subway tunnel designs are not something you knock out in a day. The MTA took a clever shortcut: to the extent possible, they rebuilt the roof using the original design. It had functioned just fine for about 80 years and they had complete drawings for it. This shortcut led to the somewhat odd appearance of the structure of the station: brand-new but old-fashioned. You don’t really see it with the column in the photo above: the original was a built-up wide-flange section, this one is a modern one-piece wide-flange section. Big deal. But when I turn to my right and take a picture of the columns between the tracks…
(Click on the photo to enlarge it.) First, the knee braces between the roof beams and the columns stopped being built in the subways in the 1940s. Second, if you look closely, all of the connectors are modern hex-head bolts, rather than the rivets used originally.
The real gem is the nature of the center columns. The standard design in the old tunnels is for these columns to be built up using four angles or bulb angles and a web plate to create short “H” columns with very wide flanges. These built-up columns were typically wider (across the flanges) than they were deep (along the web). There are not now regularly-made one-piece H-section shapes with those dimensions, and they were exceedingly rare in the past. At first glance, it looks like these columns are built the same way, but they’re actually pairs of channels with a web plate. The “MC” channels – which used to be called “ship-building channels” – have a number of sections where the flange width is well over twice the channel depth; combining two of those creates an H section wider than it is deep.
If this seems like a lot of trouble to go to fake a 1910s design, think of it as the fastest way to reopen the tunnel seventeen years ago. Then it makes more sense.
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