How are cranes removed after the completion of high-rise construction?
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These cranes are built on hydroliclifts, that lift the crane up enough to remove a section of the tower.  The lifts, then lower the crane to repeat until each section has been removed to the crane itself, which is hoisted by another crane.
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When you look at a tall tower crane, the whole thing seems outrageous -- why don't these structures fall over, especially since they have no support wires of any kind? \nThe first element of the tower crane's stability is a large concrete pad that the construction company pours several weeks before the crane arrives. This pad typically measures 30 feet by 30 feet by 4 feet (10 x 10 x 1.3 meters) and weighs 400,000 pounds (182,000 kg) -- these are the pad measurements for the crane shown here. Large anchor bolts embedded deep into this pad support the base of the crane: \n\nSo these cranes are essentially bolted to the ground to ensure their stability. In the next section, you'll learn how tower cranes "grow." \n\nTower cranes arrive at the construction site on 10 to 12 tractor-trailer rigs. The crew uses a mobile crane to assemble the jib and the machinery section, and places these horizontal members on a 40-foot (12-m) mast that consists of two mast sections. The mobile crane then adds the counterweights. \nThe mast rises from this firm foundation. The mast is a large, triangulated lattice structure, typically 10 feet (3.2 meters) square. The triangulated structure gives the mast the strength to remain upright. \n\nTo rise to its maximum height, the crane grows itself one mast section at a time! The crew uses a top climber or climbing frame that fits between the slewing unit and the top of the mast. Here's the process: \n\nThe crew hangs a weight on the jib to balance the counterweight. \nThe crew detaches the slewing unit from the top of the mast. Large hydraulic rams in the top climber push the slewing unit up 20 feet (6 m). \nThe crane operator uses the crane to lift another 20-foot mast section into the gap opened by the climbing frame. Once bolted in place, the crane is 20 feet taller! \n\nOnce the building is finished and it is time for the crane to come down, the process is reversed -- the crane disassembles its own mast and then smaller cranes disassemble the rest.
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There is no proof. All the evidence disappeared to China or the bottom of the ocean. Why were they so quick to get rid of that steel? Do you really believe that jet fuel gets hot enough to collapse an I beam? Hell, I've picked out beer cans after a bonfire. Duh! And as far as I know, airliners aren't made for knocking down buildings. They are light so they can fly. Have ever seen a crash site? There usually isn't a whole lot of recognizable things left. A building that would collapse after getting hit like that wouldn't pass a NYC building code exam.
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1) The towers are built.\n\n2) The main suspension cables are draped across the towers.\n\n3) Temporary work platforms are hung from the main suspension cables so that construction workers can work.\n\n4) The main deck is built from the work platforms.
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Try to ask mor clearlly at http://skyscrapercity.com/archive/index.php/t-160977-p-4.html
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Engineers use a cable and pulley system to pull the cables that are on the ground up to the insulators on the very tall towers.  Then they pull the cables at the end of the respective run to tighten them to specifications.
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Hello Hassan,\n\nDepending upon the materials used in the construction of said beam, it is possible that the beam has been lifted at the points of a harmonic. When the slightest breeze passes by it will induce a vibration that will continue to ascend, impelled by the very little help of the breeze. Soon, all ears nearby will be held and crying screams will be heard while the beam rings ever increasingly loud.\n\nAfter some point in time, the stresses in the beam caused by the vibration will overcome the tensile strength of the entire beam and cause it to shatter like glass.\nYour question is moot unless the construction workers can place the beam in position before the crescendo of vibration has time to escalate.\n\n-Gabe
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use the method "Remove"
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1a.  Since blasting is going to create instability in the surrounding material for a greater distance, digging will produce the more stable tunnel.  Assume you are depending upon the natural surroundings to support the shaft and not introducing artificial shoring.\n\n2a.  Technically since work is defined as the amount of force required to move a mass through a distance, both will be performing the same amount of work.  Benefit will be gained by the conveyor system which can essentially move material 100% of the time if it can be loaded continuously.  To achieved the same with cranes and trucks, there would have to be enough cranes so that a full load was constantly moving up the shaft.\n\n3.2.  Not sure what a "gigantil fisility" is let alone if one can be constructed of "concreat".  Also the debris being removed from the shaft may not be suitable component of "concreat".  Best option would be to sell it or give it away.  Probably some big holes around that could be filled in.\n\nConstructing a gigantic facility out of concrete might even be an option if you had enough Portland cement and the shaft debris was a suitable aggregate.
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Lifting Operations and Lifting Equipment Regulations
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Hemastats are removed. They are left in only by mistake
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In the US most are called Tower Cranes and they actualy lower them selves down part way then using Mobile Cranes they diss asemble them the rest of the way
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It's about time we had a "sticky" for this question, it gets asked so often.\n\nThese cranes build themselves.  Four short sections are bolted together and a small crane hauls itself up on rails located INSIDE these sections.  It then pulls up another four sections for assembly around itself and away it goes again until the crane is erected to the desired height.  The jib is assembled at ground level around the trunk and hauls itself up on rails OUTSIDE the trunk sections.
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its is assembled on site when the building project has begun and then it is dismantled on site once the contract is finished
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Just drag it upwards.
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There are many at your local animal shelter.\n\nMost of them may actually have 4 legs, but it's easy to remove them.
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Building - to top of antenna Sears Tower \n\nBuilding - to architectural top Taipei 101 \n\nthere is different catagories...