Why now for high rise? Escape wise, something more radical than staircases has to be thought of.

I think we can expect rather fewer big "landmark" and "signature" buildings that offer themselves as targets. And a possible slowing in the trend for centralisation of scattered organisations.

maybe, but don't be surprised if the towers are re-built bigger and better than before, America is in a very defiant mood.

No way the towers will be re-build... The memory of the horror is to big and sad for all the world. Targets as those towers are the problems of all our metropolies. Re-thinking these critical points is a long and probably impossable process... the solution must be political, not just architectural.
For the escape wise,i think architects schould consider more the diferent processes and dont limite themselfs to the existing law (wich is also a problem!)... a friend of mine suggest a type of "fireman staircases" attach to the facades with protections would be helfull. It looks silly and destroys all minimalist conceptions but it could be a way of starting... any more "silly" ideas?...

Any form of stair is too slow. Any form of lift would be knocked out. Although the "sky lobby" system at the Twin Towers - the first time such a system was deployed - saved many people because lifts serving the lower floors continued to operate.

All I can think of - apart from not building tall buildings - is some form of escape shute like a helter-skelter. Relatively fast, and no moving parts, but probably impractical because could not handle the huge numbers of people that a big tower contains.

It'll probably sound ridiculous, but some kind of parachute system akin to basejumping would be most appropriate for the evacuation of buildings such as these. I also think that America will rebuild the two towers, hopefully identically (though perhaps with a structural system that avoids such dramatic progressive collapse). It's worth bearing in mind though, as symbolic as the towers were to the New York skyline, neither New yorkers or architecture critics had very nice things to say about them

Here's a stupid idea...

What about having emergency escapes like the have on airplanes, those bright yellow blown up jobs, of course they could be only on the lower floor, which makes it a bit useless, but after all i'm talking about stupid ideas.

Message just received by Irish DOCOMOMO Working Party from Gustavo Araoz, US/ICOMOS <garaoz@usicomos.org>

On behalf of our members, the preservation community of our country, and
the people of our nation, the Board of Directors of the Committee for
the United States of America for the International Council on Monuments
and Sites, ask that you join us in mourning and commemorating the
thousands of our dead and innocent citizens who were brutally murdered
on September 11th by agents of unseen, sinister forces who cowardly
hide in the shadows and crevices that are permitted ironically by the
very freedoms that the United States upholds, defends and protects.

In the past, US/ICOMOS has loudly and publicly repudiated all attacks
against the cultural heritage and the architectural symbols of other
countries and cultures throughout the world. Those attacks have now
come home to wound us, creating senseless destruction, profound national
pain and a swelling anger. To the condemnation of such monstrous acts,
we now add our adherence to our unrelenting national resolve to defend,
at whatever cost and sacrifice, our way of life, our beliefs, our
traditions, and of course, the fulness of the cultural and historic
patrimony that embodies the universal values of our nation.

US/ICOMOS also wants to express our deep appreciation for the many
messages of sympathy and solidarity that we have received from friends
and colleagues all over the world. Your kind words mean a lot to us. In
many ways, this attack on us is also an affront to all of you who uphold
the human rights to the essential freedoms.

As we write this, many of our members are at work in downtown Manhattan
protecting the many heritage sites that have been endangered by the
explosions and collapse around them, such as Trinity Church and St.
Paul's Church and their graveyards, and the historic Federal Reserve
Bank. While US/ICOMOS does not know of any loss of life among our
members, two of them, Kyle Brooks and Missie Dierickx had their
apartments across from the World Trade Center Towers, and at this point
may have lost their homes and belongings.

In a burst of unfounded optimism at a time of such darkness, we cannot
but continue to hope that this will be the last chapter in terrorist
acts of war that seek to eliminate the traces and symbols of human
culture anywhere in the world.

Washington, DC, 14 September, 2001

Robert Wilburn, Washington, DC, Chairman
Richard Pieper, New York City, Vice Chairman
E Blaine Cliver, Washington, DC, Secretary
Darwina Neal, Washingnton, DC, Treasurer
Ann Webster Smith, Chariman Emeritus

Lisa Ackerman, New York City
Steade R Carigo, Sacramento, California
Edward Crocker, Santa Fe, New Mexico
Stephen J Farneth, San Francisco
Pamela W Hawkes, Boston
Stephen J Kelley, Chicago
James P Kiernan, Washington, DC
R Randolph Langenbach, Washington, DC
Spencer Leineweber, Honolulu
Frank G Matero, Philadelphia
Nora J Mitchell, Woodstock, Vermont
Saidee J Newell, Natchitoches, Louisiana
Tomas M Schmidt, Pittsburgh, Pennsylvania
Katehrine Slick, Las Vegas, New Mexico
Jeanne Marie Teutonico, Los Angeles
Troy D Thompson, Indianapolis
Manfred J A Thoms, Savannah, Georgia

Gustavo F Araoz, Washington, DC, Executive Director

Article by Hugh http://www.hughpearman.com/articles2/wtc.html

raises some good point about where corporations go from here....

It was indeed very sad to see the emblems of a fine city crumble to rubble....words cannot describe this mindless act of savery on innocent people going about their everyday business. The WTC should be rebuilt as a symbol of defiance to those who perpetrated this crime. Despite all the political hypocracy....... the USA is our lifeblood ....and our protectors....we are of the western world. Skyscrapers should still be built ....they are practical......The WTC was not designed to withstand airplanes crashing into them in such blatant terrorist acts of violence and vandalism.

From THE NEW YORK TIMES Magazine:

To Rebuild or Not: Architects Respond

"Of course one has to rebuild, bigger and better. There should be offices and a mix of activities, both cultural and business. Yes, there should be a place to mourn, but that shouldn’t be the main thing. It must be a place looking into the future, not the past."
— Bernard Tschumi, dean of the Columbia architecture school

"We must rebuild the towers. They are a symbol of our achievement as New Yorkers and as Americans and to put them back says that we cannot be defeated. The skyscraper is our greatest achievement architecturally speaking, and we must have a new, skyscraping World Trade Center."
— Robert A.M. Stern

"What’s most poignant now is that the identity of the skyline has been lost. We would say, Let’s not build something that would mend the skyline, it is more powerful to leave it void. We believe it would be tragic to erase the erasure."
— Elizabeth Diller and Ricardo Scofidio

"Whatever they take down, we’ll rebuild. I think we should provide the same amount of office space, that it’s the least we can do."
— Philip Johnson

"Something else has come out of this, and that is how much ownership people outside of New York feel about our city. Maybe it’s not just our decision. Maybe we should let the American people vote on it."
— Ralph Appelbaum

"Whatever we do in the future has got to reflect the sense that the West, its culture and values have been attacked. I would hope that we would not be deterred from going as high as the old towers were. We should not move back from that point. We cannot retreat."
— Peter Eisenman

"Once we get over the grieving, we should realize that this could be a defeat, or it could be like Chicago after the fire, in 1871, when they invented the skyscraper and changed the ways cities have grown all over the world. We should build an even greater and more innovative skyscraper."
— Terrence Riley, architecture curator, Museum of Modern Art

"It should be rebuilt. We need office space, though we don’t want to build the same towers — they were designed in 1966 and now we live in 2001. What has to be there is an ensemble of buildings that are as powerful a symbol of New York as the World Trade towers were. The life of the city depends on people living and working in the city and loving it — we want people there. We want them in a place that can be magnificent."
— Richard Meier

"'It would be the tragedy of tragedies not to rebuild this part of New York,' said Larry Silverstein, who closed on the $3.2 billion deal with his partner Westfield America Inc. in late July. 'It would give the terrorists the victory they seek,' Mr. Silverstein said in an interview from his Fifth Avenue office. He hadn't given any interviews since the attack Tuesday. Mr. Silverstein, 70 years old, a New York civic leader as well as a prominent developer, emphasized that any planning for rebuilding has to wait until after people deal with the human toll of the tragedy. He said he has been 'absolutely staggered' by the loss of life, which may include four of his employees, who are still missing."
http://www.planetizen.com/news/item.php?id=4159

http://www.greatbuildings.com/buildings/World_Trade_Center.html

Mourning the Death of Great Buildings: http://www.designcommunity.com/discussion/7011.html

It looks as if 4 smaller towers will be built as a replacement.......so there goes the height factor.

It's too early to tell: http://www.boston.com/dailyglobe2/263/living/Should_we_+.shtml

Yamasaki once considered building a single supertower rather than twin towers. Not a bad idea, if you're feeling defiant.

...Regarding an end to the skyscraper, well it is just as possible to nosedive and plough an aircraft into any low rise structure and the damage would be perhaps just as detrimental in a high density urban sprawl area. Long live the skyscraper.

or Sellafield in the right weather conditions and wipe out the Irish east coast

Congratulations paul!
the site got a mention in Frank McDonalds article in the Property times (page 18)today
interesting article on the future of the skyscraper after the attack in new York

Frank is a good auld skin ....his articles and books on Dublin's development and lack of it over the years helped to enlighten me about architecture.



[This message has been edited by GregF (edited 27 September 2001).]

http://www.ireland.com/property/top/2001/0927/top4.htm

Maybe sounds like a daft idea but how about escape capsules, like in Star Trek (dont laugh). Ten people load into a container which is fired out from the building and drifts down to earth via parachute.

I saw on TV a great proposal for the disaster site but i cant find anything else about it... Anyway, the idea is really sensible and adequate: on this same site 2 new towers will raise but this time much taller and against any terrorist attack and almost every natural disaster - 2 towers of light that touch the sky... just light. What symbolises is great and maybe not very utopic. The authors are a group of american artists.
What do you think?...

A few thoughts.

1. If the WTC had framed floors instead of concrete. Would it still have collapsed?
2. If the vertical supports were more positioned central as against circumferencial, would it still have collapsed?
3. Is it really New Yorkian to have such a central site as an unprofitable memorial?

In reply to Moz's points 1 & 2, so far as I can tell from all the books, engineering reports etc:

1. Floors were composite: steel beams supporting lightweight steel trays into which low-mass concrete for the floor was poured.

2. Both outer lattice of slender steel columns and the steel-framed core took gravitational load, whereas the outer lattice also acted as wind bracing. Floors spanned between perimeter and core with no intervening columns.

Current wisdom in engineering circles is that the collapse started at the core, and that maybe the steels there should have been better fire-protected.

The towers were certainly very cleverly and leanly engineered for the prevailing circumstances in 1970 - which took account of possible 150 mph hurricanes but not holy fools in hijacked airliners. There was no redundant structure, it was no stronger than was necessary.

In fairness to the WTC buildings - they actually performed very well (although that might seem difficult to appreciate under the calamitous circumstances involved) they maintained sufficient structural integrity to allow escape during the period of over an hour after each of the initial collisions which is quite impressive given the temperatures of 1000+ deg.

The real issue though would seem to be whether high buildings are 'escapable' in the event of a calamity - certainly the experience in the far east has not been encouraging.

As to the argument that low level buildings are equally vulnerable - this is quite simply incorrect - for example the pentagon buildings which accommodated a similar number of occupants suffered a reasonably low level of casualties by comparison to the WTC (125 V 5500 casualties).

High buildings cannot be made safe or escapable in the same way as low rise buildings. The WTC buildings performed far better than was to be expected however probably far better than contemporary structures would do under the same circumstances. Unfortunately, it still remains that tall buldings are pretty inescapable in such circumstances - at best fire can be contained and structural collapse minimised.

At 'breakneck' speed it takes a single individual 10 - 15 minutes to clear 35 floors through an open and clear stairwell - imagine that same stairwell filled with other occupants, shrouded in smoke, blocked by debris and that 10 - 15 minutes could turn into 30 - 60 minutes which is usually the outer limit of integrity in the case of fire.

So no answers then to the escape dilemma - Can structures be improved - hardly, in most cases even the most up to date technology finds it difficult enough to deal with 'normal' fires. When circumstances lead to a fire of 1000 deg it is almost impossible to guarantee performance. As to the specifics of such damage - it would not necessarliy take an airliner laden with fuel to generate such temperatures - a gas explosion or fireball within an air conditioning duct can generate similar temperatures over a very short period of time which none the less will cause serious damage.

Towers of Light: http://www.architectureweek.com/cgi-bin/awimage?dir=2001/0926&article=news_1-2.html&image=11553_image_4.jpg http://www.architectureweek.com/cgi-bin/awimage?dir=2001/0926&article=news_1-2.html&image=11553_image_7.jpg

Well, at the end of the day I think its all going to come to the simple fact of why there were [skyscrapers] built in the first place. Do we want continuse urban sprawl vs. fear of skyscrapers and terrorist attacks? But do we want to built two great towers from the late '60s, or wouldn't we want something bold and new in the 21st century?

As me Dad says, America has to ask itself 'why?'

www.wtctribute.net (http://www.wtctribute.net)

Very hard site to access, due to overloading by traffic and data transfer, but the pics are worth the effort:
http://www.geocities.com/twin09112001/disaster.html (generated by www.gallarotti.net) (http://www.gallarotti.net))

Infrared mapping: Check out the multimedia link - Mapping the Surface of a Disaster - at http://www.nytimes.com/2001/09/23/nyregion/23TOPO.html

Why Trade Center Towers Stood, Then Fell - http://www.nytimes.com/2001/11/11/nyregion/11COLL.html

Not such a stupid idea - used it myself in a final year design - though the lecturer was more concerned with high heels tearing the slide. Saw on US news and few days ago the principal now being put forward as a possible solution for escape for low rise buildings
Originally posted by rob:
Here's a stupid idea...

What about having emergency escapes like the have on airplanes, those bright yellow blown up jobs, of course they could be only on the lower floor, which makes it a bit useless, but after all i'm talking about stupid ideas.