신비한사전

A boat travels across a river, but it floats on water through the air, 38 meters above the river. This is the Pontcysyllte Aqueduct in Wales, UK, where a 307-meter-long cast iron trough transports canal water and boats across the valley. The initially proposed low stone aqueduct method would have required locks on both sides, potentially slowing down transit, and the structure would have needed to be lightweight to span the high valley. Therefore, Thomas Telford and William Jessop opted to create a massive cast iron trough instead of building a stone waterway. They erected 19 cast iron spans on 18 slender stone piers, placed the entire canal on top, and then sealed the joints with interlocking iron plates and caulking before filling it with water for testing. Thanks to this, boats could cross the River Dee while maintaining the same water level, without the need to ascend and descend locks. Completed in 1805, this aqueduct is still in use as a canal today.

As the sea encroached right up to the lighthouse, people decided to move the entire structure back instead of trying to block the ocean further. This is the Cape Hatteras Lighthouse in the US, standing over 60 meters tall and weighing more than 4,000 tons. Continued coastal erosion could have washed away the sand around its foundation, potentially destabilizing the freshwater environment where the timber supporting the foundation was placed. Engineers detached the lighthouse from its base, inserted a massive steel framework underneath, and lifted it about 1.8 meters using hydraulic jacks. The challenge was that even a slight shift in weight could cause cracks in the old brick tower. To manage this, they divided the hydraulic jacks into three sections to maintain level, monitored the load and tilt with 60 sensors, and moved it approximately 1.5 meters at a time. Over 23 days, they moved it about 884 meters to its new foundation.

There's a church whose roof is at the same level as the ground, with the entire building buried upside down underground. It's the Lalibela rock-hewn church in Ethiopia. About 800 years ago, people wanted to create a new Jerusalem in this mountainous region. However, building eleven massive churches would have involved an endless amount of work just quarrying, transporting, and reassembling stones. So, instead of bringing stones to build, the stonemasons decided to remove only the unnecessary parts of the mountain. First, they drew the church's outline on a flat rock and then dug a deep trench downwards along that line. This left a massive block of stone separated from the surrounding bedrock. The stonemasons then carved this stone from top to bottom to create the roof and walls, and dug inwards to carve out doors, windows, pillars, and ceilings from within the rock. The walls, roof, and pillars are not separate additions but are all part of a single, continuous stone mass connected to the mountain. The problem was the rain. Since the church is located in a deep pit and trench underground, it would instantly turn into a giant swimming pool after a heavy downpour.

A massive 3,000-year-old temple was cut into over a thousand pieces and moved uphill. This is the story of Egypt's Abu Simbel Temples. When the Aswan High Dam was built, the Nile River began to rise, creating the vast Lake Nasser. If the water filled completely, the temples of Ramesses II, carved directly into the rock face, would be submerged. Building a dam to hold back the water would mean constantly resisting immense water pressure. The temples, with their 21-meter-tall statues and numerous chambers carved into the cliffside, couldn't be lifted whole like a building. So, instead of moving the mountain, engineers turned it into a giant puzzle. Workers used wire saws to meticulously cut the temple and cliff into over a thousand stone blocks. Each block weighed about 30 tons. Each piece was numbered, moved to storage, and then transported one by one to a new location 64 meters higher than the original site. The temples reappeared on higher ground, 180 meters away from their original location, and were finally reopened in 1968.

A highway where cars used to zoom by transforms into a massive river in the face of torrential rain. This is the story of the SMART Tunnel in Kuala Lumpur, Malaysia. This city is situated at the confluence of two rivers, which meant that whenever it rained heavily, water would flood the urban areas. However, building a separate flood tunnel would incur enormous costs, and the roads leading into the city were perpetually choked with traffic. They needed to manage floods and ease traffic congestion, essentially facing the challenge of excavating the same land twice. So, engineers decided not to build separate channels for water and vehicles. They integrated both functions into a single tunnel. A massive stormwater tunnel, 9.7 kilometers long, was constructed, with a 3-kilometer section featuring a two-tiered roadway built within it. During normal times, cars travel on both levels. When moderate rain occurs, water is diverted solely through the bottom-most drainage channel, leaving the roadway fully operational.

In the heart of Indianapolis, USA, an 8-story office building slowly rotated like the hands of a clock. Inside, 600 employees were working as usual. The company needed a new headquarters as it grew, but demolishing the existing building would have shut down its internal telephone equipment and potentially disrupted the city's communications. So, the engineers flipped the script. Instead of moving people and equipment out, they decided to move the entire building, keeping everything inside as it was. They laid out rollers meticulously beneath the foundation and used massive jacks to lift the building slightly. As 18 people operated the jacks incrementally, the 11,000-ton structure began to inch around at a mere 38 centimeters per hour. The real challenge was the wires and pipes. Not just telephone and electrical lines, but also water, gas, and sewage pipes were all at risk of being severed. To overcome this, all lines and pipes were pre-extended to be flexible, and a temporary passage that moved with the building was even installed at the entrance.

European stone cathedrals stay cool even in the sweltering summer without air conditioning, thanks to their unimaginably thick stone walls. The Girona Cathedral in Spain has walls that average 1.2 meters thick, and up to 2.5 meters in some places. The key isn't that the stone reflects heat, but that it absorbs a massive amount of it. While the midday heat spends all its time trying to warm up these massive stone blocks, the sun has already set outside. Add to this the 35-meter high ceilings that hide the hot air near the top. It's even more surprising that measurements over six years showed the indoor temperature remained at a stable 24-25 degrees Celsius during the summer.

The airport, built on reclaimed land, is sinking 5 centimeters every year. Yet, planes continue to take off and land without issue. The secret isn't preventing the sinking, but rather re-leveling the buildings every time it sinks. They measure the height of the 900 pillars supporting the terminal, then use hydraulic jacks to lift the lower pillars and insert steel plates to adjust their height. It's like putting paper under a wobbly desk leg, but on an airport scale. The idea of continuously fixing it instead of trying to stop it is quite impressive.

In the height of Roman summer, 50,000 people sat for extended periods to watch games in the Colosseum, which had no stone roof. The secret? Instead of building a roof, they unfurled ship sails across the sky. They erected poles around the top perimeter, intricately connected them with ropes like a spiderweb, and then covered it with canvas. And who managed these hundreds of complex ropes? Not construction workers, but the navy. Sailors, who were accustomed to hoisting sails and battling the wind daily, were the experts at this sky-high roof. The idea of completely blocking out the sun, rather than just cooling the air, was truly remarkable.

A single concrete box weighs 11,000 tons and floats on water. The secret is that it's hollow inside. The moment the weight of the water displaced by the box equals the bridge's weight, the water supports it entirely from below. It's the same principle as a steel ship floating. The lakebed was soft mud, making it impossible to drive in pillars. Ultimately, engineers decided to float the bridge like a boat. They built pontoons on land and towed them out with tugboats to connect them. Even the 58 anchors driven into the lakebed and secured with cables to prevent it from drifting away in the wind – the more you look into it, the more fascinating it gets.