This fascinating series explores the machines, processes and structures that form the backbone of 21st-century living. In this instalment, Robert learns about fireproofing; finds out how miners search for specks of gold in Nevada; and discovers how a clever little device makes lifts safe.
How Do They Do It? puts the modern world under the microscope to explain the designs and processes behind our daily lives. Robert Llewellyn gets his hands dirty in a bid to better understand the technology that keeps the world moving.
This week, Robert visits fire-safety experts Warringtonfire to discover how they fireproof furniture, buildings and even glass. Modern polyester fabrics are designed to be inherently fire retardant, whilst new spray coatings help to keep metal cool. At Warringtonfire, Robert puts some of these inventions to the test and compares a modern fire-retardant sofa with an older model.
Next up, Robert heads to the hills in search of gold. More specifically, he is in Nevada to learn how prospectors find tiny specks of gold in rock. When the first pioneers ventured west on the gold rush, they crossed through Nevada without realising they were passing over one of the richest goldfields in the USA. Nevada’s Carlin Trend is a vast goldfield some 40 miles long. But the gold here is incredibly difficult to detect because it is found in such tiny quantities – as little as five grams in every tonne of rock. The gold particles are so small they are invisible even under a microscope. So how do they find it?
The answer is that the miners use one of the most poisonous chemicals around – cyanide. Gold and silver dissolve in cyanide solutions making it possible to leach the valuable metals from the worthless rock. During the last 40 years, mines in Nevada have produced nearly 2,000 tonnes of gold, at a value of around £30 billion.
Finally this week, Robert finds out how lifts were made safe with the invention of a ‘governor rope’ that moves with each elevator car. If the lift starts travelling too fast, the rope activates a brake, bringing the car to an immediate halt. Modern lifts can travel at up to 60kph and cover as much as 460,000km in 20 years of service – and all the time the passengers inside are safe and secure. This indispensible device was essential in the development of the modern-day skyscraper.
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