Inspired by the wish of a young Swiss boy in 2012, the whimsical feat of engineering known as the SlideWheel was realized this year. This is isn’t quite the giant sloshing drowning machine it appears to be on first blush, though. It begins and ends at the same shallow pool, where three- and four-person rafts are lifted into the ride by conveyor belt. What happens next is difficult to describe. It’s easier just to watch the first-person video below that demonstrates the pendulum-like motion that comes from floating while rotating.
SlideWheel moves at a modest 3 RPM, though this can be adjusted. Travel speed through the tube maxes out at 40 KPH/ 25 MPH, but will vary depending on the raft’s location, the position of the wheel, and gravity. The ride can handle up to three rafts at a time and delight 720 people per hour. A trip through the tube lasts a mere two minutes, but all those who’ve tried it say the experience seems much longer. [Wiegand Maelzer] have already received a few orders and are working on a dry version for malls and indoor amusement parks.
San Francisco’s Millennium Tower is sinking. Since its completion in 2009, the 58-story, 645-foot tall residential building has settled 16 inches and tilted perhaps 2 inches to the northwest. Since the foundation issues came to light in August 2016, the vertiginous ultra-luxury highrise has become the subject of outrage, ridicule, and at least two pieces of pending litigation.
Nothing that we build is static. Our office towers, apartment complexes, and single family homes move in response to loads applied by the environment. Buildings sway in the wind, expand and contract in response to temperature changes, and shift with the land upon which they rest. In most scenarios, these deflections are so minuscule that the occupants never even notice. Millennium Tower happens to be a large enough project with a severe enough problem that the whole world can’t help but gawk.
In foundation design, not all terra is firma. While a one or two story wood-framed building can be built safely with a shallow foundation on crummy soil, a major skyscraper requires a foundation that can transfer extremely high loads into the earth. But the strata below our city streets can consist of anything from sand to clay to solid rock, and many cities, including San Francisco, have infilled former marshes and bays with soil in order to expand their coastlines and generate valuable real estate. Millennium Tower was built in South of Market, a neighborhood that mostly used to belong to San Francisco Bay.
Suspension bridges are far and away the target of choice in America’s action blockbusters. In just the past three years, the Golden Gate Bridge has been destroyed by a Kaiju, Godzilla, a Skynet-initiated nuclear blast, and a tsunami. Americans don’t build real bridges anymore, or maintain the ones that we have, but we sure love to blow them up in movies.
There is logic here: A disaster scene involving a famous bridge serves both to root the film in the real world and to demonstrate the enormity and the immediacy of the threat. The unmaking of these huge structures shocks us because many bridges have gained an aura of permanence in our collective consciousness. Although we know when the Brooklyn Bridge was built and who built it, we feel like it has always been there and always will be. The destruction of our familiar human topography is even more disturbing than the deaths of the CGI victims, and I’m not just saying that as a misanthrope who loves bridges.
However, in all of the planning, storyboarding, rendering, and compositing of these special effects shots, nobody pauses to consider how suspension bridges actually behave. I can accept messianic alien orphan superheroes and skyscraper-sized battle robots, but I will not stand for inaccurate portrayals of structural mechanics. It’s fine to bend the laws of physics if the plot warrants it, but most suspension bridge mistakes are so needless and stupid that their only function seems to be irritating engineers.