I used the picture above once before to discuss the hole in front of Penn Station, which eventually became the Hotel Pennsylvania. Because the hotel was not yet built, this photo provides one of the few nearly-head-on views of the east facade of the station, on Seventh Avenue, which was its main facade. This is the mental image that most of us have of the building: what the Romans would have built if they had steel construction and were building railroad stations. This picture is taken near the end of construction, with some work still going on and a construction fence still up. The building opened at the beginning of September 1910. Photos from about two years earlier tell us all sorts of things about how this huge structure was built. Here’s the southeast corner, at 31st Street and Seventh Avenue, which is the far left end of the photo above:
There’s a lot going on here. First, in case we didn’t already know, the truth that the ornate granite facade is a curtain wall supported on steel becomes clear when you look to the right side of the photo, where the central pavilion (facing 32nd Street) is framed but not yet sheathed. The bare steel of the attic floor above the southeastern pavilion on the left also makes that point pretty clear. On the far right of the photo is a big hole in the ground, which is the 32nd Street tunnel carrying the tracks to the station from the east. Seventh Avenue is 100 feet wide (including sidewalks) and the amount of street between that hole and the station is maybe a quarter of that, so the tunnel work has obviously consumed the east portion of the roadway. The detail that I like the most is that the streetcar tracks (including the underground third rail) have been temporarily reconfigured to jog left around the hole. We have a fairly standard construction fence and a lot of derricks to lift steel and stone. Let’s turn the corner to the left and head west down 31st Street:
The completed stone work from the earlier picture is seen on the right, as we’re looking east-northeast. The Sixth Avenue building of Macy’s, visible on the left above the station, is at Sixth and 34th Street. (The Seventh Avenue extension was built in the 1920s.) The steel framing nearest us is fairly ordinary, and you can see the framing extending down on the left two tall levels below street grade to the platform level. That very regular X-braced grid is heavy timber, and the obvious question is why such falsework was needed, since steel erection was, by 1908, a standard form of construction in New York. The answer is that this area would be the main concourse, providing access to the platforms, and it was far from standard in design:
The completed steelwork we are seeing in the construction photo is the framing behind the interior stone walls in the 1910 completed-building photo. The big area with the wood falsework is where the steel arched roof would be built. The George Fuller Company was one of the most experienced large-building contractors in the city at the time, and I would assume they looked at the cost and speed trade-offs between (a) putting up all that wood to support the steel arches until they were completed and (b) using bridge-building techniques to brace the incomplete arches. There’s nothing inherently wrong with a brute-force solution like this.
I generally have little patience for “structural honesty” arguments, but it is a bit jarring to see the modern steel of the station being swallowed up by stone.