Wednesday, April 1, 2009

City Hall’s Call: Why Forest City Ratner’s Gehry Beekman Tower Will Only Be 50% of Originally Planned Height- It’s Structural

Nobody knew what to think when the news went out on that the Frank Gehry-designed Forest City Ratner Beekman Tower now under construction might cease construction at about half its originally planned height. (See and hear: WNYC's Downtown Housing Complex May Downsize, by Matthew Schuerman, March 19, 2009.)
NNY City Hall Speculation

We speculated:

It is amusing to toy with the idea that the building might have been stopped by the mayor himself when he realized how the immensity of the building in his own City Hall backyard might stand as a symbol to influence the debate over his administration’s sell-off of the public realm.
(See: Thursday, March 19, 2009, Willets Point Lawsuit Points Out . . .)

HDC Says “Pretty Straight Forward”

A spokesperson for the New York City Housing Development Corporation, the state authority financing the Beekman, told Norman Oder’s Atlantic Yards Report that building the project to half height was not such a big deal (emphasis supplied):

I asked NYC HDC spokesperson Catie Marshall yesterday how much the developer would be allowed to spend. "The funding for a project such as the Beekman is generally done in tranches, thus it is phased (sort of pay-as-you-go)," she responded. "In the case of the Beekman, the bonds are variable rate and only the first two tranches have been issued. In general terms, if a project is altered and does not need all of the funding, the remaining tranche(s) will not close. It’s pretty straight forward."

(See: Friday, March 20, 2009, If FCR's Beekman Tower faces 50% cut, what does that say about Atlantic Yards promises (and designs)?)

FCR Explanation: Penny Saving

Meanwhile, the Forest City Ratner organization was denying that the project wasn’t going to reach full height, attempting to convey the idea that they were stopping construction midway as some sort of typical approach to rebid or “value engineer” the project midway to save money. (See: Monday, March 30, 2009, Forest City Enterprises announces losses, asserts that AY arena is one of only two new projects to launch in 2009.)

Leaks the Answer?

Mentioning the “value engineering” of a Gehry project got us off and thinking about the problems with leaks the building might have (Monday, March 30, 2009, Gehry Leaks) and that the cessation of construction might even have something to do late-found flaws in this regard.

Answer Finally Leaks Out: A City Hall Call

Well, it turns out that we were partly right in our first speculation and partly right in our last speculation. The answer combines both. The halt to construction was called for by City Hall itself because of structural problems. Not structural problems directly in the Beekman, but structural problems caused by the Beekman in a neighboring property. The surprise is that the neighboring property is City Hall itself which is just a block away from the Beekman with pretty much the distance of City Hall Park between them.

The problem came to light just days ago when:

Engineers have discovered dangerous cracks in 200-year-old wooden beams right above Mayor Bloomberg's desk in City Hall, leading to an emergency $5.5 million contract to stop the roof from falling in.

The complicated repairs are being made in attic space above the "bullpen," where the mayor and his top aides have their work areas.

(See: Friday, March 20, 2009, Beam above Bloomie is broken.)

A Historic Challenge to Link and Identify the Problem

It took the esteemed engineering firm of Robert Silman Associates, which is handling renovations at City Hall, to diagnose the problem and recognize its relationship to the Beekman. It took very astute work on their part and a knowledge of history. The Beekman itself, which was planned to be the tallest residential structure in the city, would not itself have been a problem except for the manner in which the Brooklyn Bridge was constructed by the Roeblings. The problem is an obscure one but familiar to professional engineers who, when working with historic old buildings, should always remember to consult the profession’s site interrelationship exchange tables.

City Hall was constructed from 1803 to 1812. The nearby Brooklyn Bridge, one of the oldest suspension bridges in the United States, began construction in 1870 and was completed in 1883. The Roeblings, first John (who succumbed to infection after a construction-related accident), then his son, Washington Roebling, and eventually Washington’s wife Emily constructed the bridge using caissons so that underwater construction would be possible. As those familiar with the decompression sickness (Caisson disease) that sidelined Washington Roebling will likely know, this method of construction involves pressurized caissons where air is pumped with pressure high enough to displace, in this case, the surrounding waters of the East River.

Air Blown Under Pressure

The many years of pumping pressurized air into the river’s seabed created unstable site situations that have translated into the Beekman’s construction affecting City Hall so as to dislodge the 200-year-old beams there. It would not have been a problem for a normal-size building, but the Beekman at a planned 76 stories (it has now reached a height of 38 stories) is not your normal-size building. Its super large size pushed the compressed air from the 1870s back across City Hall Park, thus affecting City Hall.

Realizing that this was a problem on the Manhattan side of the river, engineers quickly called for an assessment as to whether similar problems will beset the unprecedentedly large Dock Street project on the Brooklyn side of the bridge. Because it would be built so close to the Brooklyn-side tower of the bridge it should be particularly susceptible to exactly the same problem. There is as yet no definitive word on whether there will be caisson air pressure site unstabilization problems affecting the two too-tall projects on both side of the river. Apparently, the proposed inclusion of a school in each of the two projects is exacerbating the problem. Asked about this, Assembly Speaker Sheldon Silver, who helped push through the Gehry-designed Ratner tower at first asked: "I have to listen to this? He then said: “What’s the matter? You don’t like Silver linings?”

No Bull-i-On: The Problem Could Have Gone Undetected But For Ratner

Thankfully, the structural weakening at City Hall was noticed earlier than it might have been, coincidentally because of Forest City Ratner’s Bruce Ratner. Mr. Ratner is a frequent contributors to Mayor Michael Bloomberg’s charities, which the mayor has been using to advance his political goals. The initial cracking in the City Hall beams was detected when Ratner stopped by City Hall to make another charitable donation to the mayor. Ratner was delivering a heavy load of gold bullion to an office safe above the mayor’s bullpen when the weight of the gold interacting with the weight from Beekman across City Hall Park apparently just became too much to bear.

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