Est. Completion Date:
October 19, 2013
The Las Vegas high Roller is a project being developed by Caesars Entertainment, the world’s largest gaming company, on a 350 acre parcel they own one block west of the strip and across the street from Caesars Palace. The total height of the structure is 550’, making it the world’s largest observation wheel. Caesars will operate the attraction, and it is part of a larger development that includes a Retail, Dining, and Entertainment (RD&E) District and the finish out of two shelled in hotel towers within the Caesar’s complex. The total value of the investment is $550M.
The San Francisco office of ARUP is the designer of the structure, assisted by the London office. The scope of work to be undertaken by American Bridge includes the supply and erection of a 529’ diameter wheel that rests on four inclined steel legs approximately 285’ above grade level supported by a transverse braced leg; the hub, spindle, bearing, and cable spoke system; and the erection (but NOT the supply) of the passenger cabins. The design, foundations, ticketing building, cabin supply, wheel queing platform, permanent wheel drive system, and electrical works are not part of the scope of this package. It was initially conceived that this would be a design build project, but upon AB suggestion Caesars agreed to continue to hold the design responsibility and ARUP’s contract.
The four tubular steel, variable diameter (up to 2.8m) structural steel support legs will be constructed first, followed by the variable diameter transverse brace (up to 3m), using conventional cranes. The legs are anchored to concrete foundations placed under separate contract, to anchor rods and a shear key supplied by American Bridge, installed under separate contract, and surveyed by AB. After concrete set, the anchor rod positions are again surveyed and translated to final leg position. A locator plate will then be field welded with a 1” fillet weld to the support leg base plate. The support leg can then be erected over top of the anchor bolts and shear key in perfect position. The support legs contain a total of 13 tuned mass dampers to arrest vibration of the structure. Total finished weight of steel in the support and brace leg system is 1,208mt.
Due to site constraints, the 495mt hub, spindle, and bearing unit will be erected in three pieces on a falsework truss that will be designed and erected by American Bridge between the support legs approximately elevation 250’. The west and east bearing assemblies will be installed on the spindle ends on the ground in the vertical position and then inserted into the hub end section, creating a complete hub and spindle end assembly. The spindle ends and hub block are steel forgings. The bearing surface on the forging is a heat treated welded overlay achieving a hardness of HRc 30 and containing a machined outer surface of 1600mm. The hub and spindle middle section is structural steel, with a weight of 237mt. The west hub, spindle, and bearing assembly will be erected by crane to the east end of the temporary truss, then translated to the west end and lowered to its steel casting bearing point. The hub/spindle middle section will then be erected in place, and bolted to the west section. The east hub/spindle/bearing assembly will then be erected, and bolted to the middle section.
The 2m diameter tubular steel rim will be erected in 6.1m segments with the assistance of radial erection struts. Each radial strut is approximately 250’ in length. The struts will be erected by three 100t chainfalls mounted on the hub, first hung vertically and then bolted to the advancing rim erection. The rim sections will also be erected with the chainfalls, and bolted to the next section by a collar splice. The wheel will be rotated during construction by a temporary drive system designed by American Bridge. This system will utilize jacks and a pulling frame. As each segment and cable spoke section is erected, the wheel will then be turned and another segment erected, and so on. The rim has a structural steel weight of 1,225mt.
AB’s work has included the selection and management of a variety of specialty suppliers from around the world, including structural steel from China, bearings from Sweden, forgings and castings from Japan, and tuned mass dampers from Germany. Erection engineering is performed by American Bridge engineers in Coraopolis, and site erection is performed by AB skilled labor and supervision on site.