Seven remarkable engineering feats

1. Aqueduct of Segovia, Spain 

Segovia is famed for one of the best-preserved roman aqueducts in the world – an engineering marvel that has truly stood the test of time. Constructed between 50 - 120 AD, the aqueduct spans 12.8 kilometres and consists of 165 stone arcs that are 30 feet tall. Skillfully designed to transport water from the Frio River to surrounding cities and towns using gravity (induced by a series of tiers, arches, conduits and the natural landscape), the system is still in partial use today, almost two millennia later. 

The aqueduct bridge was constructed using more than 24,000 granite blocks held together without mortar – making its longevity all the more remarkable. The system also features a water filtration system: ‘desanding basins’ were used to slow the flow of water, leveraging a decantation process to remove the bulk of river sand from the water supply.

2. Antibiotics, United Kingdom 

In 1928, Alexander Fleming discovered penicillin, the first true antibiotic, changing the fates of millions around the world. Prior to this discovery, infectious diseases accounted for high rates of mortality worldwide, and the average life expectancy at birth was 47 years, even in the industrialised world. Thanks to antibiotics, average life expectancy jumped by eight years between 1944 and 1972. While modern day chemical engineers are now tackling a new problem – antibiotic resistance – there is no question that this discovery changed the world of modern medicine.

3. The Bailong Elevator, China 

At 326 metres high, the Bailong Elevator in Hunan Province, China, is the tallest outdoor elevator ever built. It is also the fastest and largest loaded elevator in the world: up to 50 people can ascend the entire distance in just one minute and 32 seconds. Passengers experience a breathtaking view from their glass carriage of ravines, gorges, waterfalls and giant sandstone pillars. Attached to the side of one of the sandstone pillars using tunnels and shafts, the elevator consists of three sightseeing elevators, which can carry 4,000 one-way passengers per hour. Prior to COVID-19, around 18,000 tourists rode the elevator daily.

4. Solar panels, USA 

In 1954, Bell Labs announced the invention of the first solar panel, demonstrating its ability to convert sunlight into electrical current by using it power a small toy Ferris wheel. 

While the discovery of the photovoltaic effect dates back to 1839, it wasn’t until 1954 that this knowledge was turned to practical application – a major breakthrough in electrical engineering that opened the doors for a zero-emissions means of harnessing energy to power our world. 

The New York Times wrote that the silicon solar cell ‘may mark the beginning of a new era, leading eventually to the realisation of one of mankind’s most cherished dreams – the harnessing of the almost limitless energy of the sun for the uses of civilisation.’

5. The Great Pyramid of Giza, Egypt 

The Great Pyramid of Giza demonstrates the incredible skill of early Egyptian engineers who, despite primitive resources, built an extraordinary structure that remained the tallest structure in the world for over four thousand years. Built in 26th century BC, it comprises 2.3 million blocks of stone which were quarried and meticulously set in place for this Pharoah’s tomb. 

The entire structure stands 146 metres high, with the base length of 230 metres per side. The sides of the pyramid are perfectly aligned with the four cardinal points of the compass, even though the compass had not even been invented at that time. The outside stones were cut within 0.01 inch of a perfectly smooth surface and assembled at almost perfect right angles – modern technology still cannot place 20-ton stones with greater accuracy. 

The pyramid contained cornerstones with balls and sockets built into them, allowing expansion and contraction to contend with the elements, such as heat, cold, earthquakes and sandstorms. Such ingenuity has allowed the pyramid to endure for some 4,500 years and counting. It’s little wonder the pyramid continues to inspire and intrigue engineers to this day.

6. The Saturn V rocket, USA 

While there have been incredible advancements in space exploration technology since, the Saturn V remains the only launcher to have gotten man to the moon. A remarkable achievement of aerospace engineering, the Saturn V was the most powerful rocket to have ever flown successfully. 

At 111 metres (roughly the height of a 36-story building), the Saturn V weighed 2.8 million kilograms and generated 34.5 million newtons of thrust at launch. It was capable of launching 118,000 kilograms into earth orbit (approximately the weight of 10 school buses). On July 16, 1969, Saturn V launched Apollo 11, putting man on the moon and making history.

7. Osaka Kansai Airport, Japan 

Osaka Kansai Airport exemplifies the ability of engineers to think outside the box and innovate to solve problems. The problem: a new airport needed to be built, but there was no available land. The solution: flatten two mountains to build an artificial island in Osaka Bay, four kilometres long and 2.5 kilometres wide. 

And as if building a runway on an artificial island wasn’t challenging enough, engineers had to build a giant seawall around the island to protect the runways, along with a three-kilometre bridge connecting it to the mainland. Not surprisingly, it was the most expensive civil engineering project at the time, costing $20 billion and taking seven years to complete.