经济学人下载:电梯和摩天大楼 另一个高耸入云的俱乐部

Science and technology
科学技术

Lifts and skyscrapers
电梯和摩天大楼

The other mile-high club
另一个高耸入云的俱乐部

A new lightweight lift cable will let buildings soar ever upward
一种新型的轻型升降梯将会让建筑继续向更高处发展

WHEN Elisha Otis stood on a platform at the 1854 World Fair in New York and ordered an axeman to cut the rope used to hoist him aloft, he changed cityscapes for ever.
当艾利沙·奥的斯在1854年纽约世界博览会上站在一个高楼的阳台下，命令一个持斧的人砍断那个把他带到高空的绳索时，他彻底改变了人们对城市景观的印象。

To the amazement of the crowd his new safety lift dropped only a few inches before being held by an automatic braking system.
为了吸引人群的眼光，在新的自动制动系统起动前，他只让他的新安全电梯降落了几英寸。

This gave people the confidence to use what Americans insist on calling elevators.
这让人们在使用电梯时-美国人坚持这个称呼有了足够的信心，

That confidence allowed buildings to rise higher and higher.
也正是缘于这种信心，后来的建筑造得越来越高。

They could soon go higher still, as a result of another breakthrough in lift technology.
当另一种升降技术取得突破后，很快，高楼大厦将会继续往更高处发展。

This week Kone, a Finnish liftmaker, announced that after a decade of development at its laboratory in Lohja, which sits above a 333-metre-deep mineshaft which the firm uses as a test bed, it has devised a system that should be able to raise an elevator a kilometre or more.
本周，一家荷兰的电梯制造者—通力声称，该公司位于洛雅的实验室—该实验室坐落于一个333米深的，用于试验的矿井上方—经过数十年的研究，开发了一种可以让电梯升高到一公里甚至更高的系统。

This is twice as far as the things can go at present.
这个高度是现在电梯可以达到高度的二倍。

Since the effectiveness of lifts is one of the main constraints on the height of buildings, Kone's technology—which replaces the steel cables from which lift cars are currently suspended with ones made of carbon fibres—could result in buildings truly worthy of the name “skyscraper”.
因为电梯高度是建筑物高度的主要制约因素之一，所以通力的技术—将以碳纤维取代目前技术中，让升降车悬浮于半空的钢索—会让那些摩天大楼能够真正配得上这个名字。

The problem with steel cables is that they are heavy.
钢索的不足就是它们太重了。

Any given bit of rope has to pull up not only the car and the flexible travelling cables that take electricity and communications to it, but also all the rope beneath it.
任何指定的绳索除了要承载汽车和柔性移动电缆—让电力和通信可以和它连接起来的电缆—的重量，还要承担它们下面所有绳索的重力。

The job is made easier by counterweights.
而这些如果借助平衡力的话会轻松得多。

But even so in a lift 500 metres tall steel ropes account for up to three-quarters of the moving mass of the machine.
但是，即使在一个500米高的电梯中，钢索的重量也高达整个机械移动重量的四分之三。

Shifting this mass takes energy, so taller lifts are more expensive to run.
而要移动这个重量就很耗能，因此越高的电梯，它的运行成本就越高。

And adding to the mass, by making the ropes longer, would soon come uncomfortably close to the point where the steel would snap under the load.
在绳索越来越长的情况下，移动的重量也会越来越大，这样就会很快达到钢索的承重极限，而这些会让人们感到不安。

Kone says it is able to reduce the weight of lift ropes by around 90% with its carbon-fibre replacement, dubbed UltraRope.
通力表示，用碳纤维取代钢索可以让升降索的重量减少约90%，他们称之为“超级钢丝绳”。

Roped together
牢牢捆在一起

Carbon fibres are both stronger and lighter than steel.
碳纤维绳索比钢索更牢，却更轻。

In particular, they have great tensile strength, meaning they are hard to break when their ends are pulled.
通常，它们的拉伸强度很高，就是说当用力拉它们的两端时，它们很难会被拉断。

That strength comes from the chemical bonds between carbon atoms: the same sort that give strength to diamonds.
这种强度来自于碳原子间的化学键：这也是金钢石之所以坚固的原因。

Kone embeds tubes made of carbon fibres in epoxy, and covers the result in a tough coating to resist wear and tear.
通力公司把碳纤维制成的管状物嵌入环氧树脂，再在外层涂上坚固的涂层，以防止磨损。

According to Johannes de Jong, Kone's head of technology for large projects, the steel ropes in a 400-metre-high lift weigh about 18,650kg.
根据通力大型项目技术负责人约翰内斯-德荣表示，一个400米高电梯的钢索重量大约重18.65吨。

An UltraRope for such a lift would weigh 1,170kg.
而如果在同样的电梯中，使用能够达到相同有效高度的超级钢丝绳，后者的重量将为1.17吨。

Altogether, the lift using the UltraRope would weigh 45% less than the one with the steel rope.
总之，一个电梯，如果使用超级钢丝绳，那它的重量将比使用钢索时减少45%。

Besides reducing power consumption, lighter ropes make braking a car easier should something go wrong.
除了能够降低功效外，较轻的绳索能够制动一辆更容易会出事的汽车。

Carbon-fibre ropes should also, according to Mr de Jong, cut maintenance bills, because they will last twice as long as steel ones.
据德荣先生表示，碳纤维绳也应该能够减少维修费用，因为它们的使用寿命比钢索高一倍。

Moreover, carbon fibre resonates at a different frequency to other building materials, which means it sways less as skyscrapers move in high winds—which is what tall buildings are designed to do.
此外，在一个不同的频率上，碳纤维与其它建筑材料有着共振效应，这就是说，当高楼在大风中晃动时，这个超级钢丝绳的晃动幅度不会那么大—而这就是高层建筑设计的初衷。

At the moment a high wind can cause a building's lifts to be shut down. Carbon-fibre ropes would mean that happened less often.
当前，一场大风会让一幢建筑的电梯完全停工。但是碳纤维绳索的诞生表明这种现象不会频频出现了。

All of which is worthy and important. But what really excites architects and developers is the fact that carbon-fibre ropes will let buildings rise higher—a lot higher.
上述这些都很重要，而且是值得的。但是，真正刺激建筑师和开发商的是，碳纤维绳索会让建筑越来越高—比现在的高楼还要高很多。

Lighter, stronger ropes mean the main limiting factor in constructing higher skyscrapers would become the cost, says Antony Wood, an architect at the Illinois Institute of Technology, in Chicago.
伊利诺伊理工学院—位于美国芝加哥—的建筑师安东尼-伍德表示：更轻，更牢的绳索意味着，限制建造更高摩天大楼的主要问题将会转到成本上。

Dr Wood is also executive director of the Council on Tall Buildings and Urban Habitat, which, among other things, lists the official heights of skyscrapers.
伍德博士也是高层建筑与城市人居理事会的执行董事，该机构在有关其它方面的记录中，列出了官方规定的摩天大厦的高度。

At present the tallest is the Burj Khalifa in Dubai, which was completed in 2010 and, at 828 metres, shot past the previous record-holder, the 508-metre Taipei 101 tower.
目前为止，最高的高层建筑是迪拜的迪拜塔，完工于2010年，高达828米，完全超过了以前的最高建筑—位于台北的，高达508米的101大楼。

The Mecca Royal Clock Tower in Saudi Arabia, completed in 2012, is now, at 601 metres, the second-tallest.
于2012年完工的麦家皇家钟楼位于沙特阿拉伯，高达601米，现在是第二高建筑。

The Freedom Tower in lower Manhattan, built near the site of the World Trade Centre's twin towers that were destroyed by al-Qaeda in 2001, had its spire added in May to reach 541 metres.
曼哈顿下城的自由塔于今年三月加高了塔尖，已经达到了541米，离它不远就是以前世贸中心的双子塔，分别达到了417米和415米，

But work has now started on the Kingdom Tower in Jeddah, Saudi Arabia.
但是在2001年被基地组织摧毁。

Its exact proposed height is still a secret, but it will be at least a kilometre.
沙特阿拉伯的吉达王国塔现正在建造中，建造计划中的高度具体是多少还未公开，但是估计至少为一公里。

With a big enough budget it would, says Dr Wood, now be possible to build a mile-high skyscraper.
伍德博士说，它的建造成本将会是个庞大的数字，可能相当于现在建造一英里高的摩天大楼的成本。

Even with carbon-fibre ropes few of such a building's lifts would go all the way from the entrance lobby to the observation deck.
即使使用碳纤维绳索，要直接从入口大厅乘电梯到观景台，就算在如此规模的高层建筑里也很少见。

Most would debouch into intermediate sky lobbies, where passengers could change lifts.
大部分都是涌进中间的大厅，从那里乘客们再换乘电梯。

Such an arrangement is already familiar. Many skyscrapers are more like three-stage rockets, with different buildings stacked one on top of another—offices, a hotel and apartments.
类似的安排人们早已经了解了。很多摩天大楼更像三级火箭，里面不同功用的建筑一个堆一个—办公楼，酒店和公寓。

Sky lobbies mark the frontiers between these uses.
中间的大厅就是这些不同功用建筑的分界点。

But carbon-fibre ropes will allow each of these stages to be taller, too.
但是同样，碳纤维索能让这些不同功用的建筑越来越高。

The sky's the limit
天空不是无界的

Nor need carbon-fibre lift-cables be confined to buildings.
碳纤维电梯电缆并不局限于建筑的使用。

They could eventually make an idea from science fiction a reality too.
它们最终也会从科学幻想变成现实中存在的东西。

Space lifts, dreamed up in the late 1950s, are a way of getting into orbit without using a rocket.
人们在二十世纪五十年代想象出来的太空电梯就是一个不需要火箭，就可以进入轨道的设备。

Building one would mean lowering a cable from a satellite in a geosynchronous orbit above the Earth's equator while deploying a counterbalancing cable out into space.
建造这样一个设备将意味着，会架设一条在地球同步轨道卫星下方，地球赤道上方的电缆，同时还可以在太空中有效利用这个对重平衡电缆。

The cable from Earth to the satellite would not be a classic lift rope because it would not, itself, move.
从地球连接到卫星的电缆将不会成为一个经典的电梯电缆，因为它本身将不再移动。

But it would perform a similar function of support as robotic cars crawled up and down it, ferrying people and equipment to and from the satellite—whence they could depart into the cosmos.
但是，当机器人汽车在它上面往返于地球与卫星之间，运送人们和设备时，它将执行一个类似的支持功能，同时人们从卫星上可以出发遨游宇宙。

There are, of course, many obstacles to building such a lift.
当然，建造这样一种电梯还有很多问题，

But the answer to one—finding a material that is light and strong enough for the cable—might just have emerged from that mineshaft in Finland.
但是，答案就是—寻找一个足够透光性和牢固的材料来制作电缆—而这种材料可能刚好就产自于芬兰的矿井。