credit: Lloyd Alter/ test tower in Rottweil
TreeHugger has been following the development of the MULTI elevator system from ThyssenKrupp, which was unveiled to the public for the first time last week in Rottweil, Germany, running in their new test tower.
The hilarious thing about the MULTI is that the engineers designing it thought that they were building a new kind of elevator that did what every other elevator did: go up and down. The difference was that it didn’t have a rope; instead, each cab had a linear induction motor running on rails, so that you could put as many cabs in a shaft as you wanted. But with more than one cab in a shaft it couldn’t go back down, so they developed a mechanism to let go sideways from the up shaft and then go down a down shaft, sort of running in a big circle, modelled on the Paternoster continuous elevators that used to be popular in Europe (and were known as “the elevator of death”). A terrible video here:
They saw the MULTI as a sort of vertical moving sidewalk, with cabs coming every 20 seconds or so, stopping at sky lobbies at fixed intervals where one would transfer to a local elevator; the market was in the super tall buildings where the elevators were becoming a significant bottleneck and took up as much as 40 percent of the floor area. With no rope there was no limit in how high a building could be. The MULTI would run much more slowly than some of the fastest elevators, but it would seem faster because there was no waiting, and it would use far less energy because in conventional elevators the cable weighs a lot, and they fight against air resistance in the shaft at high speed. More precisely:
Operating on the basic premise of a circular system, such as a paternoster, MULTI will use rope-less linear technology to operate elevators, and a single loop can incorporate various cabins. With a targeted speed of 5 m/s, the system will enable near-constant access to an elevator cabin every 15 to 30 seconds, with a transfer stop every 50 meters. Passengers will enjoy reduced wait times, and the option of double entries on the ground floor improves ease of access in large buildings.
The promotional video:
Then someone looked at it and said "you could run this sideways as well as up and down" and the engineers wondered "why would you want to do that?" For one thing, it gave the architect more freedom to do something different, which can be a blessing or a curse. As Antony Wood of the Council on Tall Buildings and Urban Habitat noted at the launch:
The holy grail of elevators is to free up that core and being able to move without a rope then you can move incline, horizontal and the real potential of that is to change how buildings are designed.
The MULTI is relatively simple in concept but complicated in execution. Here you see its support without the cab, so you can see the mechanism behind. The mechanism behind the support contains linear induction motors that run on the rails up and down or side to side. It then comes to the turntable where it stops, the mechanism turns 90 degrees while the cab stays vertical, and then it starts moving again. In a shaft full of cabs it runs very much like a subway system, with enough headway between the cabs so that it can stop, unload and load the passengers, and start again without running into another cab.
Here is a video I took of Markus Jetter hitting the big blue button for the unveiling; you can see the cab come down, move sideways to the turntable and track and then go up again.
credit: Lloyd Alter/ Student design for building with MULTI
But as noted, the MULTI can do a lot more than just go up and down. If that was all the Multi did it would be enough, and the world would soon be full of oddly shaped buildings. But as I learned at the unveiling of the first full size working MULTI at ThyssenKrupp’s new test tower in Rottweil, Germany, people are making bigger plans.
We first saw this in London, where it was proposed that instead of going up, the MULTI should go down to service the London Underground. There are hundreds of different tunnels crisscrossing under the city and many stations that are not universally accessible. It is almost impossible to drill a straight elevator shaft but the MULTI could pick its way around tunnels and services, zigzagging from the surface to platform. Here’s a video about it:
But others see it as an entirely new form of transportation. Elevator consultant Jay Pop described a situation many are familiar with: take a large urban hospital. Different specialties might be in different wings or buildings, and people spend a lot of time going up and down, and pushing gurneys down long corridors to the next elevator. Imagine instead that you get on a little elevator cab and instead of picking a floor, you pick the exact department you want to go to. The MULTI would then take you down, across and up again, travelling in three dimensions directly to your destination.
Or imagine a large building that is mixed use, as Anthony Wood suggests most big buildings in the future will be, a mix of offices, hotel and residential. This has always been difficult and expensive because of all the separate elevator shafts; Imagine instead the different uses having their own lobbies, with elevator cabs sharing the shafts but having different starts and finishes.
Or imagine crowded cities where instead of everyone fighting over the ground plane, that people had options, the ability to take the high road. When the elevator runs horizontally as well as vertically it creates entirely new ways to make connections at all levels, very much like those images of the cities of the future that we have been showing on TreeHugger for years.
Or as ThyssenKrupp CEO Andreas Schierenbeck noted:
Eventually it could solve the last mile. With the horizontal movement of the Multi you can connect buildings, you can connect trains stations with your buildings, you could even have your own cabin waiting for you at your hotel room – all these things which have been a little bit science fiction maybe three, four, five years ago are now possible.
Ben Hammersley of Wired was moderator of the presentation of the MULTI, and calls it one of the most extraordinary inventions of the last few years, "One potentially will change the shape of our cities and and design of our cities more than the self-driving car."
I suspect he’s right. The MULTI could become an entirely new kind of transportation system, moving people in any direction, connecting them to other buildings and to high capacity transit systems. It could deliver people the way pneumatic tubes used to deliver mail: through tubes directly to their destination running vertically, horizontally and even diagonally.
And unlike the self-driving car, it is not competing for ground space with pedestrians and cyclists and cars but has it’s own dedicated right of way at another level. Unlike the car where people expect to have private personal space, nobody but Donald Trump and a very few other people expect to have a private elevator; we are used to sharing them.
Many will say (me among them) that the last thing we need is something that encourages people to walk less. But this is not going to replace walking; It is a very expensive way to get around, and as can be seen in the photo, it takes a lot of equipment to drive those linear induction motors.
It may replace a lot of elevators but it won’t replace our feet. It’s the combination of horizontal and vertical movement that makes it so intriguing; Elevators basically have defined the form of our buildings, and those buildings defined the form of our cities; that all may change now.
credit: Lloyd Alter and Dennis Poon
A few thoughts:
– This is so obviously a much better idea, I’m chagrined that I hadn’t already designed a complete system myself.
– I initially didn’t realize this was a "gallery" article. Makes a big difference.
– looking at the second image, I found myself strongly hoping there won’t be an "eject" button. 🙂
– I hope that builders will install these in new buildings. They could also install the old kind, then as people adjust to the MULTI version, decommission the old kind and turn them into more rooms.
But people are lining up to try it out, and the first building to actually be designed around it has been announced by real estate developer Coen van Oostrom, CEO of OVG Real Estate- the East Side Tower in Berlin. OVG built the Edge building that has been called the greenest office building in the world.
I was thrilled to be a guest of ThyssenKrupp at the unveiling of the MULTI, and acknowledge that they paid for my travel and accommodation. But that’s not what makes me a cheerleader for this; it really is a different kind of thinking that will change buildings. It takes up a lot less space and uses a lot less energy. It might dramatically increase the use of public transport instead of private cars as it feeds passengers directly from building to transit system. It may well be a whole new way of getting around town.
More on MULTI in TreeHugger:
ThyssenKrupp unveils model of the MULTI, a vertical mass transit system
New elevator is like a vertical mass transit system
ThyssenKrupp tops off testing tower at 800 feet
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…or take another peek at MULTI ropeless elevator goes up, down and sideways!