PDA

View Full Version : Bronx Whitestone Bridge



Edward
April 28th, 2003, 09:45 PM
http://www.mta.nyc.ny.us/bandt/html/bronxw.htm

Before the Bronx Whitestone Bridge opened on April 29, 1939, the Triborough Bridge, five miles to the west, provided the only vehicular connection between Queens and the Bronx. The Bronx Whitestone opened to traffic a mere 23 months after the awarding of its first construction contract so that motorists could cross it on April 30, the opening day of the 1939 New York World's Fair in Flushing Meadow Park.

Today, the bridge looks as modern and elegant as when it served as the gateway to the fair's "World of Tomorrow." As part of the massive bridge project two major recreational areas were developed, Ferry Point Park in the Bronx and Francis Lewis Park in Queens.

The bridge spans the East River. On the Bronx side are the residential communities of Unionport and Schuylerville and connections to the Hutchinson River Parkway, the Bruckner Expressway, and the Cross Bronx Expressway. On the Queens side are the residential communities of Whitestone and Malba and connections to the Cross Island Parkway and the Whitestone Expressway.


From NYCroads.com:
http://www.nycroads.com/crossings/bronx-whitestone/

PROPOSING A NEW QUEENS-BRONX SPAN: In 1905, speculators proposed construction of a bridge over the East River from Whitestone, Queens to Ferry Point in the Bronx. In anticipation of the bridge, developers built the upscale neighborhoods of Malba, Beechhurst in the northern Queens community of Whitestone, along the East River shoreline. Facing opposition from area residents, who feared that the rural character of Queens would be destroyed, the proposed bridge was shelved.

Nearly a quarter century later, in 1929, the influential Regional Plan Association (RPA) revived plans for a fixed crossing between north-central Queens and the Bronx. The bridge, which was to be part of an "inner belt" in New York's circumferential highway system, would enable motorists to travel between Long Island, upstate New York and New England without passing through high-density areas in western Queens. On February 25, 1930, as part of his plan to expand his parkway system into New York City, Robert Moses, who served as New York City parks commissioner and arterial coordinator, proposed a "Ferry Point-Whitestone Bridge" that would enable motorists from the Bronx and Westchester to reach his Long Island state parks.

As the 1930's progressed, Moses had additional reasons to construct the Bronx-Whitestone Bridge. First, when it opened in 1936, traffic filled the eight lanes of the Triborough Bridge between Manhattan, the Bronx and Queens. The bridge was to provide relief for the Triborough Bridge. Second, the bridge was to provide a link from the north to the new airport at North Beach, which eventually became known as LaGuardia Airport. Finally, and perhaps most importantly, the bridge was to provide a direct link for upstate New York and New England motorists to reach the 1939-1940 World's Fair, which Moses chaired.

Moses received authorization to build the Bronx-Whitestone Bridge from the New York State Legislature in April 1937. The new bridge was to be administered by Moses' new Triborough Bridge Authority.

Still, the bridge proposal ran into opposition. Local residents were displeased at the quick decision by Moses to raze 17 homes in Malba. Moses defended his decision, responding that the condemnation was necessary to complete the project on time. Objections were also raised by the RPA, which said that the bridge should not be built unless provisions were made for rail transit. While the RPA said that the transit tie-in would not have to be immediate, the bridge structure would have to be strong enough to handle both vehicle and rail traffic. To Moses' favor, the RPA had no serious allies on its proposal.




On the Queens side of the Bronx Whitestone Bridge lies the residential community of Malba.

http://www.wirednewyork.com/bridges/bronx_whitestone_bridge/whitestone_bridge_malba_27apr03.jpg


The Francis Lewis Park in Queens in the shadow of the Bronx Whitestone Bridge.

http://www.wirednewyork.com/bridges/bronx_whitestone_bridge/whitestone_bridge_francis_lewis_park_27apr03.jpg

ZippyTheChimp
April 28th, 2003, 10:49 PM
The original Bronx Whitestone was more elegant, but not as stable. Similar in design to the Tacoma Narrows (Galloping Gertie), it was reinforced after Tacoma Narrows collapsed. In the 40s, bracing was installed at the towers, as were the trusses that run above the roadway. In the mid 80s, a tuned mass damper was installed on the bridge to eliminate wind induced oscillations.

The problem now is that all the alterations have made the bridge too heavy for the cable system. Another project is underway to reduce the weight of the span. The steel trusses will be replaced with a composite material.

billyblancoNYC
April 29th, 2003, 01:44 PM
NICE! *I live in a "devlopment" that was carved out of the park on the other side of the water from Malba. *I see the bridge and water from my balcony! *It's very relaxing.

Man, is super nice is Malba and Beechhurst (and Whitestone, too) - HUGE houses. *One piece of junk was bought for $1.5 mil, knocked down, and they're replacing it with a 10K sq. ft. house. *A lot of Meditteranean style houses, too.

Well, enough of me. *Just wanted to share.

ZippyTheChimp
April 29th, 2003, 09:40 PM
That is not quite correct.

While there were differences with Tacoma-Narrows (2 lane roadway), the bridge did oscillate in high winds. The trusses were not immediately added. Cable stays were installed in 1940, but that did not correct the problem. The bridge was closed in 1943 during high winds. The trusses were added in 1946.

The bridge was closed again in the 60s during a storm. Then the mass damper was added. If the trusses aren't needed, why
bother replacing them with lighter material - just remove them.

ZippyTheChimp
April 30th, 2003, 06:53 AM
I agree. I didn't mean to imply that the bridge was unsafe.
I remember reading somewhere that the lead engineer argued that the bridge would not collapse, but Moses said it didn't matter if no one used it.

Is there any chance the retrofit will restore the pedestrian walkway?

Kris
April 30th, 2003, 08:43 PM
They should add one as soon as possible. (Ditto for the Verrazano-Narrows Bridge.)

I'm glad to learn it will be restored to its original elegance.

Kris
April 30th, 2003, 08:48 PM
Is there a bike path?

Kris
April 30th, 2003, 08:53 PM
No: http://www.transalt.org/bridges/whitston.html

ZippyTheChimp
April 30th, 2003, 10:02 PM
On the above site, report on how easy it would be to install
a bikeway and separate walkway on Verrazano, since it was designed to have them. There is space on both sides of the upper roadway between the inner and outer cables.

What a view that would be.

Gulcrapek
April 30th, 2003, 10:13 PM
There's a plan to add a walkway fairly soon.

Kris
October 11th, 2003, 08:12 PM
October 12, 2003

WHITESTONE

A Onetime Thing of Beauty Gets a Little Prettying Up

By ALISA ROTH

When the Bronx-Whitestone Bridge opened in 1939, Robert Moses called it the finest suspension bridge ever. He admired the two tall and narrow towers that supported the pale green span and praised what he described as its "light-ness and absence of pretentious ornamentation.''

Barely two years later, the bridge, which had been designed by Othman Ammann, the Swiss engineer whose legacy also included the George Washington and Verrazano-Narrows Bridges, got a little less beautiful. A series of stabilizing braces were installed that obstructed its elegant lines and weighed down its light form.

The bracing was a clumsy attempt to stabilize the Whitestone after the Tacoma-Narrows Bridge, a similar structure in Washington State, collapsed spectacularly in high winds in 1940.

Now, thanks to new developments in aerodynamics and structural engineering, the bridge is being returned to the original form that Moses so admired. A 30-month, $32 million project, scheduled to be completed this year, is replacing the heavy steel trusses with lightweight fiberglass fairings, which will also make the bridge safer.

The fairings are triangular pieces that, in effect, ''slice'' the wind so that it doesn't hit the bridge head on.

"The fairing has an extraordinary capacity to reduce the kinds of motion that can cause damage,'' said Michael C. Ascher, president of the M.T.A. Bridges and Tunnels. "The fairing is really just a means of streamlining the bridge and giving it a shape so that the air flows around it very smoothly.''

The roadway will also be replaced with a lighter, stiffening surface.

What is not clear is whether the additional supports added to the Whitestone Bridge over the last six decades were necessary: "Whether the retrofitting would have gone on if Tacoma hadn't gone down is difficult to say," said Richard Scott, author of the 2002 book "In the Wake of Tacoma: Suspension Bridges and the Quest for Aerodynamic Stability.''

How much the heavy metal trusses and other fixes really stabilized the bridge is also unclear; a recent study showed that the trusses did little to reduce the kinds of motions that put the bridge in danger.

Studies also showed that the various additions were putting unnecessary strain on the old bridge structure, Mr. Ascher said. He hopes that the new fairings will work so well that all of the old supports can be removed, bringing the bridge's design even closer to the original form.

But, he added: "The structural needs have really driven this project. The aesthetics are an added bonus."


Copyright 2003 The New York Times Company

ZippyTheChimp
October 13th, 2003, 08:49 AM
Work almost complete
http://www.pbase.com/image/22111240.jpg

North2South
October 13th, 2003, 08:48 PM
That is a beautiful bridge. Sometimes when I go visit my cousins over in Paramus, NJ I drive over that bridge. I love the late-evening look to it.

Kris
February 18th, 2005, 05:25 AM
February 18, 2005

A Bridge Too Fat

By SEWELL CHAN

Graphics: Part One (http://graphics8.nytimes.com/images/2005/02/17/nyregion/bridge.gif) | Part Two (http://graphics8.nytimes.com/images/2005/02/17/nyregion/bridge2.gif)

http://graphics8.nytimes.com/images/dropcap/t.gifhe Bronx-Whitestone Bridge has a weight problem.

Over the decades, the 65-year-old suspension bridge has been bulked up to make it more stable. But now engineers have decided that it has grown too beefy.

"We put this bridge on a diet," said Michael C. Ascher, the president of M.T.A. Bridges and Tunnels, an arm of the Metropolitan Transportation Authority. "Here's a bridge that's 65 years old. It got a little heavy around the midsection. Just like with the human anatomy, as you get on in years, lean is better. In this case, instead of putting an extra strain on your heart and other organs, it's putting a strain on the supporting structure, the skeleton, of the bridge."

When the work is completed a year from now, the steel and concrete bridge will have shed 6,000 tons, or one-quarter of its total suspended weight. Engineers say the decreased weight will reduce the strain on the bridge's steel cables, make it more durable and lengthen its life by decades, if not centuries.

Last year, workers completed the removal of steel trusses that were installed on each side of the bridge in 1946, after the notorious collapse of a bridge in Washington State. In June, they will begin replacing the bridge's concrete deck with a lightweight steel version that is being built in Brazil.

The project to decrease the bridge's load, which follows years of wind and stress tests on laboratory models, is possible because of advances in aerodynamic design.

The Bronx-Whitestone Bridge has long been known for its slim and graceful profile. It was built in less than two years to serve visitors to the New York World's Fair in Flushing Meadows-Corona Park and it opened to traffic on April 29, 1939 - the day before the start of the fair.

Stretching 2,300 feet between its two towers, the span was the fourth longest in the world. At the ribbon-cutting, Robert Moses, the highways and parks czar who oversaw the bridge's construction, called it "architecturally the finest bridge of them all."

But a year later, a catastrophe on the West Coast shook that image.

On Nov. 7, 1940, the deck of the Tacoma Narrows Bridge twisted itself apart and plunged into the water below during a fierce windstorm. No one was killed, but the collapse, captured on film, instantly became one of the most infamous engineering failures in history.

The prevailing theories in bridge design at the time paid little heed to aerodynamics, according to Henry Petroski, a professor of civil engineering and of history at Duke University who has written extensively on bridge design.

"The idea that a bridge roadway or a deck could undulate, could be moved vertically by the wind - that was just not thought to be something to worry about," he said. "The idea was to make the deck, the roadway of the bridge, as slender as possible. The aesthetic model was driving this, and it was generally thought that these bridges were so big, massive and heavy, built of steel and concrete, that the wind was just not going to move them. And that was wrong."

Even before the Bronx-Whitestone opened, engineers noticed that its deck would occasionally sway in the wind and shift back and forth, lengthwise, between the two steel towers.

The Bronx-Whitestone was neither as long nor as narrow as the Tacoma Narrows, but the same engineer, Leon S. Moisseiff, had worked on both bridges. The chief engineer of the New York bridge, Othmar H. Ammann, was on a commission that investigated the failure of the Washington bridge.

Mr. Ammann insisted that the Bronx-Whitestone was stable, but its pendulum-like movement alarmed drivers and pedestrians and Mr. Moses ordered it stiffened.

"He felt that the risk of losing motorists and therefore revenue far outweighed what the engineers said and that this perception of instability was unacceptable," said Darl Rastorfer, the author of "Six Bridges: The Legacy of Othmar H. Ammann" (Yale University Press, 2000).

In 1940, diagonal stiffening cables were installed on the bridge. In 1946, two steel trusses were erected on the sides of the bridge to stiffen it more. The trusses resulted in the elimination of the pedestrian walkways and the widening of the bridge from four to six lanes of traffic.

Bridge enthusiasts lamented that the installation of the trusses marred the bridge's aesthetic qualities. "It ruined the view of the skyline of Manhattan," Professor Petroski said.

As if those changes were not enough, engineers installed one more device - a counterbalance known as a mass damper - to the underside of the bridge in 1986 as yet another component for stability. Finally, an increase in traffic - from 6.3 million vehicles in 1940 to 45.2 million last year - has added stress, although the weight of the bridge itself is the greatest concern for engineers.

As a result of all this, the bridge has become too heavy and increasingly vulnerable to wear and tear. "Every time we added features, we were adding to the weight of the bridge," Mr. Ascher said.

To increase the bridge's longevity, engineers looked for ways to make the bridge lighter, while maintaining its ability to withstand wind. They also recruited help from engineers at two universities. In December 1998, Canadian scientists attached devices to the bridge to measure wind and vibration. Over two years, the data was transmitted to the University of Western Ontario.

Researchers there also built miniature models of the bridge made of "aluminum and some balsa wood and some plastic and some piano wire," according to J. Peter C. King, a civil engineer who directs the university's wind-tunnel laboratory.

The models were put in a 200-foot-long wind tunnel, which simulated average winds of 140 miles an hour and gusts of 210 miles an hour. The latter figure would represent winds stronger than a devastating hurricane.

Dr. King concluded that replacing the concrete deck with lightweight steel, removing the trusses and re-evaluating the need for the mass damper could yield more sophisticated ways of keeping the bridge stable.

"The thought at the time was more brute force - let's throw more stiffness at it and see what happens - rather than to try something more elegant or subtle," he said.

Meanwhile, at Lehigh University, in Bethlehem, Pa., researchers made a prototype of the proposed steel deck. Over nine months, they simulated the effects of a truck passing over the deck 239 million times. That amounts to about 175 years of traffic - about a century longer than the 75-year minimum life span for the new, post-diet bridge.

Last April, workers completed the replacement of the trusses with wind fairings - lightweight fiberglass structures that slice and deflect the wind as it buffets the bridge. The project, which cost $32 million, restored the bridge to its original appearance.

This spring, the replacement of the deck will start.

One lane will be closed to traffic at any time, but a temporary movable barrier will allow three lanes of traffic to move in the peak direction - toward the Bronx in the morning, toward Queens in the evening - during the commuter rush. The work is expected to last 101/2 months and cost $136.7 million.

Instead of the old asphalt coating, the new deck will have a surface of epoxy and sand to prevent skidding. For drivers, the only noticeable change will be the end of potholes.

At 61, Mr. Ascher is four years younger than the bridge. He described its re-engineering as one of the most intellectually challenging projects in his nearly 15 years at the bridge and tunnel agency.

"I think the bridge is in better shape than I am," Mr. Ascher said. "In many respects, I envy engineers coming into this business now for the first time. Technology has changed so dramatically that there are new, exciting, innovative ways to extend the lives, almost indefinitely, of these structures. I wish I was much younger and just coming in now, rather than being at the twilight of my career."

Copyright 2005 (http://www.nytimes.com/ref/membercenter/help/copyright.html) The New York Times Company (http://www.nytco.com/)

Scruffy88
January 29th, 2006, 07:57 PM
As of right now, no pedestrian walkway and no plans for it. Its a shame. It would be so convenient to have a bike path to Queens from the east side of Bronx

Bob
February 20th, 2006, 12:19 PM
While I would love to see a parallel Whitestone Bridge put up, I can understand how the residents south of the current span would feel about losing their homes. To handle the traffic, perhaps a parallel Throgs Neck Bridge, with full interchange at the south of the bridges over the water, would be worthwhile.

No matter how you slice it, another bridge is needed to handle volume, and these things are cash cows that pay for themselves.

ablarc
February 22nd, 2006, 09:09 AM
The way really long bridges and tunnels are being built in Europe and the Far East, we would have built a bridge across Long Island sound by now.

In infrastructure construction, as in social policy, political prestige and practically everything else in which we were once pre-eminent, except for popular culture: we look like we're losing our cutting edge as the world's leader.

brianac
December 3rd, 2008, 05:02 AM
Last updated: December 1, 2008 04:19pm

MTA Awards $193M Contract for Bronx Bridge

By Paul Bubny (http://www.globest.com/cgi-bin/udt/im.author.contact.view?client_id=globest&story_id=175501&title=MTA%20Awards%20%24193M%20Contract%20for%20Br onx%20Bridge&author=Paul%20Bubny&address=http%3A//www.globest.com/news/1298%5F1298/newyork/175501%2D1.html&summary=NEW%20YORK%20CITY%2DThe%20four%2Dyear%20re construction%20project%20on%20the%20Bronx%2DWhites tone%20Bridge%20will%20be%20followed%20by%20furthe r%20work%20on%20this%20span%20and%20the%20agency%2 6%23146%3Bs%20other%20crossings.)

http://www.globest.com/newspics/nyc_bronxwhitestone.jpg
Bronx-Whitestone Bridge

NEW YORK CITY-The Metropolitan Transportation Authority on Monday awarded a $192.8-million contract for reconstruction on the Bronx-Whitestone Bridge connecting the Bronx to Queens and Long Island. The contractor--Conti of New York, LLC--is scheduled to start work on the four-year, three-stage project by year’s end, according to a release from MTA Bridges and Tunnels.

Over the course of the project, the entire 1,785-foot long elevated Bronx approach to the bridge will be replaced from the ground up with a completely new structure, including foundations and 15 double-arch concrete piers to support a widened roadway constructed of steel girders and concrete deck, according to the release. The new structure will be wider to provide lanes and shoulders that meet present-day width standards, although the number of travel lanes on the Bronx approach will remain the same: three in each direction.

The initial stage of the Bronx approach project involves constructing the new piers and foundations, and removing the median barrier. That work will last approximately a year-and-a-half, beginning by year’s end, according to the release.

The second major stage of the project will entail demolition of the existing roadway, lane by lane, and constructing the new roadway superstructure over the course of two-and-a-half years. The third major stage, which is expected to be completed over the final four months of the project, will involve demolishing the existing piers and final site improvements such as landscaping and draining upgrades.

The 2,300-foot long, 74-foot wide suspension span, which will mark its 70th anniversary next year, has been the subject of several projects in recent years to extend its life by reducing the load on the cables. "The approach roadway is reaching the end of its useful life, and this construction project is central to maintaining the integrity of the 69-year-old Bronx-Whitestone Bridge for many decades to come," says David Moretti, acting president of MTA Bridges & Tunnels, in a statement.

As part of the $2.5-billion, self-funded 2008-2013 capital improvement program-- announced last March, MTA Bridges & Tunnels--has further projects in mind for the Bronx-Whitestone Bridge, including similar renovation work on the Queens approach. The agency also has projects planned for the Throgs Neck, Robert F. Kennedy--formerly Triborough--Verrazano-Narrow, Henry Hudson, Cross Bay Veterans Memorial and Marine Parkway-Gil Hodges Memorial bridges, along with the Queens-Midtown and Brooklyn-Battery tunnels.
Some of the projects will continue phases of work that began in the current 2005-2008 capital program period. The program is being financed by bonds backed by the agency’s toll revenue, according to MTA.

http://www.globest.com/news/1298_1298/newyork/175501-1.html?sector=newyork

Copyright 2008 ALM Properties, Inc.

ablarc
December 3rd, 2008, 07:55 AM
From the standpoint of proportion and detail, this is New York's most elegant bridge. After the rebuilding, will it still be that?

lofter1
December 3rd, 2008, 09:51 AM
With all those double piers down below it might look a bit awkward.

"End of it's useful life" : A term that should send chills down everyone's spine.

So much of the massive infrastructure of the USA is 60 - 80 years old and is coming up on the expiration date.

And we got no money to build 'em new and better. One solution: Open the borders to a million guys willing to get their hands dirty and earn a couple of bucks a day. We could become the new Dubai.

Merry
July 25th, 2009, 01:23 AM
What a fabulous photo:

http://4.bp.blogspot.com/_1dZif8zHiaI/RzymhLUhQfI/AAAAAAAAAUI/CbWBSEkuM3E/s1600/blog_throgs_neck_bridge_getty_images.jpg

Merry
January 5th, 2013, 04:13 AM
Less Bronx-Whitestone Bridge Yielded More Stability During Hurricane Sandy

By DAVID W. DUNLAP

https://www.nytimes.com/images/2012/12/20/blogs/20121222Wind/20121222Wind-blog480.jpg
David W. Dunlap/The New York Times
The Bronx-Whitestone Bridge, seen from Malba, Queens.
One very windy day in 1968, the Bronx-Whitestone Bridge began to oscillate crazily,
leading drivers to abandon their cars in panic.

But on an even windier night in 2012, as Hurricane Sandy howled across Long Island Sound and buffeted the span, the bridge stood all but unmoving. The difference? Six thousand fewer tons of steel trusses, which were removed in 2004.

The trusses had been installed in 1946 to stiffen the bridge deck and lessen the chances that the 2,300-foot-long span would break apart in the wind, as the Tacoma Narrows Bridge (“Galloping Gertie (http://youtu.be/j-zczJXSxnw)“) did in 1940.

But it turned out the trusses were doing more harm than good. Their weight was shortening the bridge’s life span by further stressing the structure. From an aesthetic point of view, they spoiled the slender lines of one of the most beautiful bridges in New York. And when those 70-mile-an-hour winds hit the bridge in November 1968, the deck oscillated all the same, as much as 10 inches.

Instead of trusses, the bridge is now equipped with aerodynamic fiberglass fairings along the deck, which streamline the airflow around the suspended span. During Hurricane Sandy, the bridge was closed to traffic as it sustained winds of 50 to 55 miles an hour, and gusts up to 80 miles an hour. It reopened at noon the next day.

“Our engineers were very pleased with the performance of the bridge,” said Aaron Donovan, a spokesman for the Metropolitan Transportation Authority, which owns and operates the Bronx-Whitestone through its bridges and tunnels (http://www.mta.info/bandt/html/btintro.html) division. “There were no instabilities recorded.”

https://www.nytimes.com/images/2013/01/04/blogs/20130104Wind3/20130104Wind3-blog480.jpg
David W. Dunlap/The New York Times
Detailed view of the aerodynamic fiberglass fairings that deflect wind load
around the suspended deck of the Bronx-Whitestone Bridge.

Much credit for solving the problems of the Bronx-Whitestone Bridge goes to Alan G. Davenport (http://www.nytimes.com/2009/07/26/science/26davenport.html) (1932-2009) and his colleagues at the Boundary Layer Wind Tunnel Laboratory (http://www.blwtl.uwo.ca/Public/Facilities.aspx) at Western University in London, Ontario. A new biography by Siobhan Roberts, “Wind Wizard: Alan G. Davenport and the Art of Wind Engineering (http://press.princeton.edu/titles/9824.html)” (Princeton University Press), details the work that has gone into preparing skyscrapers and bridges for an event like Hurricane Sandy.

Ms. Roberts, 41, a freelance science writer, was in town during the storm. “I was definitely thinking of the Bronx-Whitestone, knowing that it was all rigged up to record every quiver.” she said. “I was doubtful that it had any instability, given what it’s gone through in the last 10 years.”

The same was true for 601 Lexington Avenue, the 59-story skyscraper-on-stilts formerly known as Citicorp Center. In her book, Ms. Roberts revisits the harrowing summer of 1978 when Mr. Davenport and his colleagues helped determine that the tower was in danger of imminent collapse in certain winds. An emergency welding program, undertaken as hurricane season approached, left the tower “fit to withstand a 700-year storm,” Ms. Roberts wrote. (She suggested the base of the building as the rendezvous for our interview, to underscore her confidence.)

https://www.nytimes.com/images/2013/01/04/blogs/20130104Wind4/20130104Wind4-blog480.jpg
Courtesy of Western University
In the “Three Little Pigs” experiment, researchers at Western University blew this full-scale house
apart with hurricane-strength pressure, to measure what structural systems failed and why.

Mr. Davenport’s concern was not limited to long bridges and skyscrapers, Ms Roberts wrote. He worried about low-rise buildings, she said, in part because “the ability of a community to cope and recover turns on the survival of these Everyman structures.” In 2001, engineers at Western began the “Three Little Pigs” project. The goal was to subject a two-story, 1,900-square-foot, code-compliant brick house to hurricane-force pressures.

Since then, two houses have been torn asunder to provide a better understanding of what structural systems fail under hurricane conditions, and why. One house had a gable roof: the classic, inverted V-shape in which two sloping planes rise from two parallel walls and meet along a center line. The other had a hip roof, in which four planes rise from all four walls, converging either at a point or along a center line. Many other tests have been conducted on roof sheathing, window openings, soffits and sidings, as well as on the form of the structures.

“We don’t tend to think about the shape of the roof when we buy a house, except aesthetically,” said Prof. Gregory A. Kopp of Western University. “But hip roofs are definitely better than gable roofs.” Their structural and aerodynamic superiority, he said, is borne out in testing and in field observations after big tornadoes, when hip-roof houses remain intact while roofless houses nearby turn out to have been gabled. “Roof shape makes a big difference,” Professor Kopp said.

http://cityroom.blogs.nytimes.com/2013/01/04/less-bronx-whitestone-bridge-yielded-more-stability-during-hurricane-sandy/#more-444208

Ninjahedge
January 7th, 2013, 09:41 AM
OK.... they TELL us that they did the experiment... but do not give us any word on what systems failed?

TEASE!!!


I'll huff and puff..... :P