Lifts and skyscrapers - The other mile-high club 2

Lifts and skyscrapers
电梯与摩天楼

The other mile-high club
摩天大楼高一英里

A new lightweight lift cable will let buildings soar ever upward
新款轻型电梯缆索使楼房得以建得更高

Jun 15th 2013 |From the print edition

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. To the amazement of the crowd his new safety lift dropped only a few inches before being held by an automatic braking system. This gave people the confidence to use what Americans insist on calling elevators. That confidence allowed buildings to rise higher and higher.
1854年，于纽约举办的世界博览会上，艾利莎?奥的斯（Elisha Otis）站在一个平台上，让人拿斧子砍断了吊起平台的绳子，城市自此改变了容颜。奥的斯新发明的安全起重机只下落了几英尺就被自动制动系统控制住，这令在场的人们感到不可思议。人们从此才有信心使用美国人执意称作“elevator”的电梯。这种信心后来一再拔升建筑的高度。

They could soon go higher still, as a result of another breakthrough in lift technology. 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 (3,300 feet) or more. This is twice as far as the things can go at present. 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”.
由于一项突破性的电梯技术，建筑有可能再创新高。本周芬兰电梯制造商-通力（Kone）宣称其已设计出一种能将电梯高度提升1,000米（3,300英尺）甚至更高的电梯系统。之前通力在位于罗荷亚(Lohja)的实验室已研发了10年。该实验室坐落在一个333米深的矿井上，公司将其作为试验台。这个高度是目前电梯可建高度的两倍。通力采用的技术是将目前吊轿厢用的钢索换成碳纤维绳。因为电梯的效能是制约建筑高度的主要因素，这一技术可能使建筑成为名副其实的“摩天大楼”。

The problem with steel cables (or “ropes” as they are known in the trade) is that they are heavy. 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. The job is made easier by counterweights. But even so in a lift 500 metres tall (the maximum effective height at the moment) steel ropes account for up to three-quarters of the moving mass of the machine. Shifting this m

ass takes energy, so taller lifts are more expensive to run. 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. Kone says it is able to reduce the weight of lift ropes by around 90% with its carbon-fibre replacement, dubbed UltraRope.
使用钢索（或业界熟知的“绳子”）的问题在于重量太重。每一特定部分的绳子不单要拉起轿厢、携带电力和通讯设备的柔性移动缆索，还要承受下方所有绳子的重量。平衡锤一定程度上能缓解这个问题。但即便如此，对于一个高达500米（目前最大有效高度）的电梯，光是钢绳就占据了这台移动的机器四分之三的质量。移动这个大块头需要能量，因而电梯越高，运营成本也就越高。如果不断增加绳子的长度，总质量也会相应提升，钢索很快就会接近那个令人不安的极限，因不堪重负而折断。通力称如果使用其号称“超级绳”的碳纤维绳，就能减轻电梯吊绳90%的重量。

Roped together
捆起来

Carbon fibres are both stronger and lighter than steel. In particular, they have great tensile strength, meaning they are hard to break when their ends are pulled. That strength comes from the chemical bonds between carbon atoms: the same sort that give strength to diamonds. Kone embeds tubes made of carbon fibres in epoxy, and covers the result in a tough coating to resist wear and tear.
与钢相比，碳纤维力量更强、重量更轻。尤其要强调的是，碳纤维绳拉伸强度较高，拉伸两端，很难折断。这种强度来源于碳原子间的化学键：同样的化学键使钻石坚硬无比。通力把碳纤维管放入环氧基树脂中，然后用坚韧表层覆盖以防磨损。

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. An UltraRope for such a lift would weigh 1,170kg. Altogether, the lift using the UltraRope would weigh 45% less than the one with the steel rope.
通力的大型项目技术主管-Johannes de Jong称，400米高的电梯所用的钢绳重达18,650公斤。换做“超级绳”只有1,170公斤。整体而言，与钢绳相比，使用“超级绳”能减少45%的重量。

Besides reducing power consumption, lighter ropes make braking a car easier should something go wrong. Carbon-fibre ropes should also, according to Mr de Jong, cut maintenance bills, because they will last twice as long as steel ones. 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. 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.
使用轻型绳会减少电耗，而且一旦发生意外，制动轿厢也会

变得更容易。De Jong还告诉我们，使用碳纤维绳还能减少维修费用，因为它们的使用寿命是钢绳的两倍。另外，碳纤维与其他建筑材料的震动频率不同，也就是说强风条件下，碳纤维绳比摩天楼震动的次数更少，而这一点正符合高层建筑的设计原则。目前，强风可导致一栋建筑的电梯关闭。如果碳纤维绳投入应用，这种情况会更少出现。

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.
这些因素都意义重大。但真正令建筑师和开发商感到兴奋的是，碳纤维绳使建筑得以建得更高，而且高出很多。

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. 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. 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. The Mecca Royal Clock Tower in Saudi Arabia, completed in 2012, is now, at 601 metres, the second-tallest. The Freedom Tower in lower Manhattan, built near the site of the World Trade Centre’s twin towers (417 metres and 415 metres) that were destroyed by al-Qaeda in 2001, had its spire added in May to reach 541 metres. But work has now started on the Kingdom Tower in Jeddah, Saudi Arabia. Its exact proposed height is still a secret, but it will be at least a kilometre.
芝加哥伊利诺伊理工学院（Illinois Institute of Technology）建筑师安东尼?伍德（Antony Wood）称，重量更轻、强度更大的绳子研发成功意味着建造更高层的摩天大楼的主要限制因素就只剩下成本了。伍德博士还担任高层建筑和城市居住理事会（Council on Tall Buildings and Urban Habitat）执行干事一职，该理事会的职责之一是列出得到官方认可的摩天楼高度。目前最高的建筑是迪拜的哈利法塔(Burj Khalifa)。哈利法塔于2010年完工，楼高828米，超过了之前的纪录保持者-508米的台北101大楼。沙特阿拉伯的麦加皇家钟塔饭店（The Mecca Royal Clock Tower）落成于2012年，楼高601米，是目前第二高楼。曼哈顿下城的自由塔（The Freedom Tower）所建位置邻近2001年被基地组织摧毁的世贸中心双子塔（417米和415米）。自由塔的尖顶已于今年5月份建好，最终达到了541米。不过位于沙特吉达（Jeddah）的王国塔（Kingdom Tower）如今已开工了。其精确拟建高度还未公开，但至少有1,000米。

With a big enough budget it would, says Dr Wood, now be possible to build a mile-high (1,600-metre) skyscr

aper. 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. Most would debouch into intermediate sky lobbies, where passengers could change lifts (not least because a mile-high lift which seemed to stop on every other floor would not be popular; it would be unutterably tedious and might force the poor souls on board to make eye contact).
伍德博士称，如果预算资金充足的话，现在有能力建起1英里高（1,600米）的摩天楼。即便使用了碳纤维绳，也很少有建筑的电梯能从前厅直达观景台。大多数都会终止于中转性质的天空大堂，乘客可以在这里换乘电梯（主要是因为人们是不会喜欢每隔一层停一次的1英里高的电梯的；乘坐过程的沉闷难以言表，而且这些可怜的乘客或许还得彼此对视）。

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. Sky lobbies mark the frontiers between these uses. But carbon-fibre ropes will allow each of these stages to be taller, too.
这类设计已经很普遍了。许多摩天楼更像三级火箭，不同建筑层层堆叠在办公大楼、酒店及公寓楼上。天空大堂为这些功能各异的建筑分界。碳纤维绳也使每一级建筑得以建得更高。

The sky’s the limit
天空才是极限

Nor need carbon-fibre lift-cables be confined to buildings. They could eventually make an idea from science fiction a reality too. Space lifts, dreamed up in the late 1950s, are a way of getting into orbit without using a rocket. 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. The cable from Earth to the satellite would not be a classic lift rope because it would not, itself, move. 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.
碳纤维电梯缆索不只适用于建筑。最终，它们有可能使科幻小说中的想法成为现实。要是能乘坐于20世纪50年代构想出的太空电梯，不用火箭就能进入轨道。要建成这种电梯，需要从地球赤道上空的对地同步轨道卫星上放下一缆索，同时在太空中配置一平衡缆索。连接地球到卫星的缆索算不上传统的电梯吊绳，因为它本身不能移动。其功能类似于提供一个支撑物，机械轿厢沿着爬上爬下，运送人和器械往返于卫星，并由此进入宇宙。

There are, of course, many obstacles to building such a lift. 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.
修建这款电梯当然会

阻力重重。不过那种适合做缆索的轻而强的材料，或许已在芬兰的矿井诞生了。