7 ms·

I went to a talk by an SOM architect a few years ago, while Tapei 101 was under construction. He said the principal limiting factor for the height of a super-t

by jordanb 13y ago

I went to a talk by an SOM architect a few years ago, while Tapei 101 was under construction. He said the principal limiting factor for the height of a super-tall structure is economics. In fact buildings over sixty stories or so don't make much sense in any real-estate market -- not even Manhattan or Hong Kong -- if viewed from the perspective of real estate as a commodity. Where supertalls make economic sense is if they can be turned into a prestige address when the building becomes a landmark. With respect to wire rope, there is already synthetic rope with dramatically better tensile strength, and it's displacing wire rope in many applications. Synthetics have a lot less hardness than steel though, and are subject to abrasion. I don't know if a carbon fiber rope would be harder than a steel rope or not, but I know from experience that CFRP panels are not nearly as hard as steel plate.

durkie 13y ago
There are a wide variety of coatings out there that could address this -- especially for an application requiring some flexibility like this, there are a wide variety of polyurethanes that have super high abrasion resistance compared to steel. It would probably also be practical to simply modify the bearing surfaces as well.
- ars 13y ago
  The abrasion problem is more internal than external. The individual fibers run against each other when the bend (since some bend more than others). Without some elasticity the internal forces will destroy the cable. Not sure how elastic CF is compared to steel. They may be able to help with some clever rope making techniques.
contingencies 13y ago
I too saw Taipei 101 under construction... incredible to think it's in a serious earthquake zone. there is already synthetic rope with dramatically better tensile strength, and it's displacing wire rope in many applications The article did mention the use of a dual layer anti-abrasian coating for durability. Honestly though, why increase height and density still further? There are stupendous issues here with efficiency with regards to food, water, and HVAC - if nothing else. My personal view is that cities of the present are essentially anachronisms spawned from 20th century post-industrialism intertia: artifacts of outmoded labour markets, planning laws and now-quaint geospatial efficiencies. As the cost of living in cities rises due to the shortage of land, the requirement for importing food and water, and the artificiality of maintaining a reasonable healthy lifestyle in high density urban environment, my bet is that, broadly speaking, emerging labour markets (our type of industry, for example) based on new technologies for communications and a reformed education system will cause a mass migration of professionals away from cities, back to a more sustainable, decentralized model. Sort of like the green banker-belt outside of London, but on a far larger scale. In short, I believe that while the city will not disappear, its face will change .. and certainly not primarily through ever-taller buildings.
- wisty 13y ago
  I think GDP was shown to grow almost quadratically with density. It wasn't so much about efficiences, as omnipresent services. If you can walk past 10 hotdog vendors on the way to work, you'll probably buy one.
  - contingencies 13y ago
    Interesting stat. Got a source? Good for health? No. Good for the environment? No. Good for corporate profits, ease of taxation, and established measures of economic trajectory including GDP? Yes. This is the story of the city, and its inhabitant is you.
    - nsp 13y ago
      "Good for health?" Manhattan has some of the lowest obesity rates in the country due to inhabitants reliance on walking/public transit over driving. There are few studies that show a 2 year life expectancy vs rural areas in the UK, but it's not a totally clear cut win for rural areas overall. "Good for the environment? No." Yes, actually - it's a lot more efficient to deliver services to people in densely populated areas than when they're spread thinly across the country side. "Per capita emissions in New York, Toronto and Barcelona are only a third of their national average, and the emissions of Tokyo, London and Seoul come in at about half of their countries' level." - http://www.newscientist.com/article/dn16819-city-dwellers-harm-climate-less.html http://www.newscientist.com/article/dn16819-city-dwellers-ha... - http://green.blogs.nytimes.com/2009/04/01/the-comparatively-green-urban-jungle/ http://green.blogs.nytimes.com/2009/04/01/the-comparatively-... has a ton of other sources, including a brookings institute study and some others No disagreement on corporate profits. Cities are also great as birthplaces of movements, musical genres, schools of art, and political theories. Think the east village during punk, detroit in the 50s for rock, the salons of paris around the French Revolution, etc etc. There are definitely great reasons to live in rural areas, but being a city dweller is far from inherently worse.
      - contingencies 13y ago

by jordanb 13y ago

durkie 13y ago

There are a wide variety of coatings out there that could address this -- especially for an application requiring some flexibility like this, there are a wide variety of polyurethanes that have super high abrasion resistance compared to steel. It would probably also be practical to simply modify the bearing surfaces as well.

ars 13y ago
The abrasion problem is more internal than external. The individual fibers run against each other when the bend (since some bend more than others). Without some elasticity the internal forces will destroy the cable. Not sure how elastic CF is compared to steel. They may be able to help with some clever rope making techniques.

contingencies 13y ago

I too saw Taipei 101 under construction... incredible to think it's in a serious earthquake zone. there is already synthetic rope with dramatically better tensile strength, and it's displacing wire rope in many applications The article did mention the use of a dual layer anti-abrasian coating for durability. Honestly though, why increase height and density still further? There are stupendous issues here with efficiency with regards to food, water, and HVAC - if nothing else. My personal view is that cities of the present are essentially anachronisms spawned from 20th century post-industrialism intertia: artifacts of outmoded labour markets, planning laws and now-quaint geospatial efficiencies. As the cost of living in cities rises due to the shortage of land, the requirement for importing food and water, and the artificiality of maintaining a reasonable healthy lifestyle in high density urban environment, my bet is that, broadly speaking, emerging labour markets (our type of industry, for example) based on new technologies for communications and a reformed education system will cause a mass migration of professionals away from cities, back to a more sustainable, decentralized model. Sort of like the green banker-belt outside of London, but on a far larger scale. In short, I believe that while the city will not disappear, its face will change .. and certainly not primarily through ever-taller buildings.

wisty 13y ago
I think GDP was shown to grow almost quadratically with density. It wasn't so much about efficiences, as omnipresent services. If you can walk past 10 hotdog vendors on the way to work, you'll probably buy one.
- contingencies 13y ago
  Interesting stat. Got a source? Good for health? No. Good for the environment? No. Good for corporate profits, ease of taxation, and established measures of economic trajectory including GDP? Yes. This is the story of the city, and its inhabitant is you.
  - nsp 13y ago
    "Good for health?" Manhattan has some of the lowest obesity rates in the country due to inhabitants reliance on walking/public transit over driving. There are few studies that show a 2 year life expectancy vs rural areas in the UK, but it's not a totally clear cut win for rural areas overall. "Good for the environment? No." Yes, actually - it's a lot more efficient to deliver services to people in densely populated areas than when they're spread thinly across the country side. "Per capita emissions in New York, Toronto and Barcelona are only a third of their national average, and the emissions of Tokyo, London and Seoul come in at about half of their countries' level." - http://www.newscientist.com/article/dn16819-city-dwellers-harm-climate-less.html http://www.newscientist.com/article/dn16819-city-dwellers-ha... - http://green.blogs.nytimes.com/2009/04/01/the-comparatively-green-urban-jungle/ http://green.blogs.nytimes.com/2009/04/01/the-comparatively-... has a ton of other sources, including a brookings institute study and some others No disagreement on corporate profits. Cities are also great as birthplaces of movements, musical genres, schools of art, and political theories. Think the east village during punk, detroit in the 50s for rock, the salons of paris around the French Revolution, etc etc. There are definitely great reasons to live in rural areas, but being a city dweller is far from inherently worse.
    - contingencies 13y ago