Halfway Done

One block form last week’s IRT subway construction photo, we have Broadway and 135th Street in 1900:

For some reason, there are relatively few construction photos at this stage. The trench has been dug, the foundation constructed, and the steel framing for the tunnel was erected, at least for about 75 feet of tunnel, but the tunnel floor is not in place and neither is any of the concrete vaulting: horizontally-oriented vaults between the steel beams for the roof, and vertically-oriented vaults spanning between the side columns for the exterior walls.

How do I know 75 feet? The tunnel framing repeats on five-foot spacing, and I believe I’m counting 15 columns. Maybe I’m off one column one way or the other.

I’m a little surprised at what appears to be a brick wall on the left and stone-block foundations below the center columns. The IRT used a lot of mass concrete – in the vaults for example – and mass concrete and unreinforced masonry serve pretty much the same purpose in building.

Finally, to touch on a different technology, the stiff and awkward poses that the laborers are inevitably in isn’t a reflection of slow shutter speeds. By 1900, in direct sunlight, a photo could be taken reasonably quickly. It’s because the average person was still not very familiar with having their picture taken, and it seems most felt they should pose as if a painter was creating a portrait.