The da vinci mode
E&T gets an exclusive preview of the rotating Da Vinci Tower, the building of the future.
You are in your penthouse suite facing the desert. At a spoken command, your view begins to shift. Slowly your whole floor rotates so that you begin looking out over the city. Another word - and the movement stops.
Welcome to the Da Vinci Tower in Dubai. Work on the rotating tower, the brainchild of Italian architect Dr David Fisher, is set to start soon and, if successful, promises to be a bold leap forward in skyscraper design.
Rotating buildings are not that new, just look at the old Post Office Tower in London. However, they tended to have only one segment that moved, usually the top, and in one direction only. The Da Vinci's 80 floors, hooked on to a stable central core, will be able to move independently and in either direction, The ideal testing ground for such a design is Dubai, which has the money and the desire to be different. But the Florence-based Dynamic Architecture Group emphasises that this is more than a marketing gimmick for another desert showpiece. If all goes well, it hopes to have similar towers on every continent.
Construction will be a souped-up version of the familiar pre-fab system. A 30,000 square metre factory in the port of Jebel Ali will turn out the living modules. Much like a Huf Haus, these will arrive on site fully-constructed, with electrics, plumbing and air conditioning installed. They will just need 'hooking' onto the slots on central silo. This reinforced concrete core is the only part to be built on site. It will have stairs, lifts, pipe work and other infrastructure. It will take 12 modules to form each floor, and each floor should take a week to complete. In total, there will be around 200 apartments, self-contained villas at the top and a hotel at the base. The designers estimate that the prefabrication approach should cut construction time from 30 months (for a traditional build) to 18 months. It will also mean a smaller workforce. There will be an estimated 90 people on site compared to more than a thousand if you were to do this the standard way. The Jebel Ali factory would then need a further 700 people. The factory assembly and small workforce should improve build quality. Dr Fisher compares the assembly line to an aircraft plant which can turn out wings or fuselages to the same high-specification time after time. Both the quicker build time and smaller workforce make the project much cheaper to deliver - although the Dubai tower is still going to cost around $330m. Another benefit is that, once you are up and running, you can start paying back your investors, because you can churn out similar buildings and ship them from your handily-positioned factory. That looks set to start soon - as Dr Fisher revealed to E&T, the company will shortly announce that the next site for a rotating tower will be in Moscow.
Power and plumbing
Before that, though, they have to overcome any design problems. Two major issues for the building are power and plumbing. If your floor is on the move, how do you make sure that when you flush the toilet the water goes where you want it to, and that when you turn on the light you have a secure connection? Les Robertson is a renowned structural engineer who has designed hundreds of tall buildings including New York's World Trade Centre. He is part of the group which will deliver the Da Vinci Tower. Robertson explained that getting power to the rotating apartments is relatively easy. The principle will be the same as that of a moving train gathering power from a third rail or an overhead line. Also, many appliances can get power wirelessly. As for the plumbing, the engineers have looked at combining all the water needed to come in through the sprinkler system. This reduces the pipe work and provides a ready set of 'nodes' for accessing water, although you would need a pressure reducer between the pipes and the sinks. Water would be heated on site so that only cold will have to be pumped in. Robertson explains: "You would have a flex connector, like a fire hose, and you will plug it in when you want to take water in. As you rotate, there will be another plug-in point."
Another design issue is the bearings, and again Robertson is sanguine about having all the floors hanging off a central silo. "I don't see any real difficulty," he says. "We would take all the gravity load on the floor or ceiling, most probably the ceiling. "At the top there would be an inward pull and at the bottom, an inward push, and the floor below would pull in the opposite direction." You can lift the modules into place one by one, or a complete 'doughnut' could be hoisted up via a roof top crane. "They could then slide up the silo. The units are pretty light," says Robertson. "I don't think that is critical, and all the lifts and stairs are in the silo."
For the project to really make money, the factory will have to turn out similar towers for other parts of the world, and that is where another factor comes in - earthquakes. Robertson explains: "The silo takes whatever forces are on the building. Building code requires two lateral force systems. The silo is one but the second is not obvious. "In Japan, the Philippines, America and other places you need two lateral force systems."
As Dubai is in zone 2a, which is a moderate seismic zone, the latter is not so crucial. However, getting permission for a Da Vinci clone tower to go up in Tokyo is another matter. When the tower is finally up, all these technical issues will be hidden between floors, and people will only see a building constantly reshaping itself.
The green tower
The project's green credentials have already sparked a lot of interest. It was short-listed for an award at the recent Clean Equity Monaco Conference which showcased emerging environmental technology companies.
According to Fisher, the Da Vinci Tower will be so energy efficient it will have enough surplus to power five similar-sized buildings. That power will come from two sources. Firstly, and most obviously, photovoltaic cells on the apartment roofs will capture the plentiful Dubai sun. Secondly, and more unusually, there will be 48 carbon fibre wind turbines mounted horizontally between each floor. Fisher's calculations show that each turbine should generate about 0.3MW of electricity. This compares with about 1-1.5MW from a normal turbine. With around 4,000 hours of wind a year in Dubai, he estimates, there is more than enough power to harness. Of course, this is an average that will vary from floor to floor in the building. Two other factors are the pulls of the turbines on the central core and the noise. Extra insulation between floors, as well as the design of the turbines themselves, will help dampen the noise.
Structural engineer Les Robertson believes the stresses on the central core can be solved by the rotation itself. "One issue with tall buildings is that they tend to oscillate in the wind because of vortex shedding," he explains. Vortex shedding are pools of low pressure on the lee side created by wind flowing past a blunt object. High buildings sway back and forth towards these and without dampening measures can end up shaking uncontrollably. Robertson says: "In high winds, you could rotate the building, so it is shaped in the optimum direction." That would negate the vortex shedding. According to Robertson, it should be possible to make almost everything for the outside of the silo from reusable items. "The whole idea is very romantic and has caught the imagination of a lot of people," he concludes
For more images, visit www.dynamicarchitecture.net [new window]