SPEAKER_00: Amazing, fascinating stories of inventions, ideas and innovations. Yes, this is the podcast about the things that have helped to shape our lives. Podcasts from the BBC World Service are supported by advertising.
SPEAKER_02: 50 Things That Made the Modern Economy with Tim Harford Here's a little puzzle for you. One day, on her regular journey to work, a woman decides
SPEAKER_01: that she's going to take a mass transit system instead of her usual method. Just before she gets on board, she looks at an app on her phone that gives her the exact latitude and longitude. The journey's smooth and perfectly satisfactory, despite frequent stops. And when the woman disembarks, she checks her phone again. Her latitude and longitude haven't changed at all. What's going on? The answer? This lady works in a tall office building and rather than taking the stairs, she's taking the lift. We don't tend to think of lifts or elevators as mass transportation systems, but they are. They move hundreds of millions of people every day and China alone is installing two thirds of a million elevators a year. The tallest building in the world, the Burj Khalifa in Dubai, has over 300,000 square metres of floor space. The brilliantly engineered Sears Tower in Chicago has more than 400,000. Imagine such skyscrapers, sliced into 50 or 60 low-rise chunks, then surrounding each chunk with a car park and connecting all the car parks together with roads and you'd have an office park the size of a small town. The fact that so many people can work together in large buildings on compact sites is only possible because of the elevator. Or perhaps we should say because of the safety elevator. Elevators themselves have existed for a long time. Archimedes is said to have built one in ancient Greece. In 1743 at the Palace of Versailles, Louis XV used one to clandestinely visit his mistress. Steam power went further. Matthew Bolton and James Watt, giants of Britain's industrial revolution, produced steam engines that ran muscular industrial elevators hauling coal up from the mines. But while these elevators all worked well enough, you wouldn't want to use them to lift people to any serious height. Because inevitably something would go wrong. The elevator would plunge down through the shaft, loose ends of the rope flapping in the darkness, passengers screaming into oblivion. Most people can walk up five flights of stairs if they must. Nobody in their right mind would want to take an elevator to such a deadly height. So what mattered was making a lift that was not only safe, but demonstrably safe. Both the innovation and the demonstration fell to a man named Elisha Otis. At the 1853 World's Fair in New York, Otis climbed onto a platform which was then hoisted high above a crowd of onlookers, nervy with anticipation. The entire contraption looked a little like an executioner's scaffold. Behind Otis stood a man with an axe, which can only have added to the sense that a spectacular death was about to occur. The axeman swung down onto the rope, the crowd gasped, Otis's platform shuddered, but did not plunge. All safe gentlemen, all safe, boomed Otis. The city landscape was about to be turned on its head by the man who'd invented not the elevator, but the elevator break. Turned on its head is right, because the elevator transformed where in a building the highest status areas were. When the highest reaches of a six or seven story building were reached only by an arduous climb, they used to be the servants' quarters, the garret for struggling artists. After the invention of the elevator, the attic became the loft apartment, the garret became the penthouse. The elevator flourished alongside two complementary sets of innovations, the steel and reinforced concrete that made it practical to build tall buildings, and the subways and other urban transit systems that could bring large numbers of people into dense urban cores. In the quintessential high-rise centre, Manhattan, elevators and the subway are symbiotic. Without the density that the skyscrapers provide, it would be hard to run a subway system efficiently. Without the subway system, nobody would be able to get to the skyscrapers. The result is a surprisingly green urban environment. More than 80% of Manhattanites travel to work on the subway or by bike or on foot, ten times the rate for America as a whole. A similar story can be told for high-rise cities across the planet, from Singapore to Sydney. They tend to be highly desirable places to live, as witnessed by people's willingness to pay high rents. They're creative, as measured by a high output of patents and a high rate of start-ups. They're rich, as measured by economic output per person. And relative to rural and suburban areas, they're environmental utopias, with low rates of energy use per person and low consumption of petrol. This minor miracle – wealth, creativity and vitality in a modest environmental footprint – would be impossible without the elevator. Yet the elevator seems unfairly underrated. We hold it to a higher standard than most other forms of transport. We're pleased if we must only wait a couple of minutes for a bus or a train, but grumble if we have to wait 20 seconds for an elevator. Many people are nervous of elevators, yet they're safe – at least ten times safer than escalators. Frankly, the elevator is a faithful servant that is too often ignored. While we take the lift for granted, it continues to evolve. The challenges of ever-taller skyscrapers are being met by super-light elevator ropes, and by computer controllers that will allow two lifts to shuttle up and down a single shaft independently, one above the other. But often the older, simpler ideas still work. For example, making the wait for an elevator pass more quickly by putting full-length mirrors in the elevator lobby. And the elevator's naturally energy efficient, because elevator cars have counterweights. There's always room for improvement, of course. The Empire State Building, still the most iconic skyscraper in the world, was recently retrofitted in a $500 million effort to reduce the building's carbon emissions. The retrofit included elevators with regenerative brakes, so that when a full car comes down or an empty car heads up, the elevator supplies power back to the building. But the truth is that the Empire State Building was always energy efficient by the simple virtue of being a densely packed vertical structure next to a subway station. One of the organisations that designed the building's retrofit is the visionary environmental group, the Rocky Mountain Institute. They have a super-efficient, environmentally sustainable headquarters high in the Rocky Mountains. But as the journalist David Owen points out, it's 300 kilometres from the nearest public transit system. Staff have to drive to work and even shuttle between buildings more than a kilometre apart from each other. Of course, the Rocky Mountain Institute is a showcase for environmentally efficient design ideas, including high-tech coatings on the windows, krypton-filled triple glazing, a water reuse system and energy-saving heat exchanges. But one of the most environmentally friendly technologies is on display in buildings all around us. It's a green mode of transport that moves billions of people every year, and yet is so overlooked it can hide in plain sight as the answer to a lateral thinking puzzle.
