WHY HEAVY-DUTY VEHICLES CHOOSE EXPANDER SYSTEM PIVOT PINS
Powerful forces of nature can potentially cause terrible disasters, and they seem to be on the rise. So, safety and resilience should always be the primary concern when designing large structures, such as bridges, or one of the tallest Ferris wheels in the world.
When the first forerunners to Ferris wheels were constructed — possibly in 17th century Bulgaria — no one could have imagined the sheer size of the Las Vegas High Roller in their wildest dreams. Until late 2021, it was the tallest Ferris wheel globally, rising 168 meters (550 ft) above the Las Vegas Strip towards the Nevada sky, dwarfing the surrounding buildings.
Attached to the rim, which is 143 meters (469 ft) in diameter, are 28 observation cars, each 40-passenger capacity. A complete revolution takes 30 minutes, providing a magnificent view of the surrounding Las Vegas Valley.
Reaching new heights
The name Ferris wheel emanates from the one built for the 1893 World’s Columbian Exposition in Chicago by George Washington Gale Ferris Jr. It was 80 meters (264 ft) tall, which must have seemed gigantic at the time.
The 21st century has seen a race to construct the tallest Ferris wheel. Las Vegas High Roller had held the title since 2014 but is now overtaken by the Ain Dubai in the United Arab Emirates, which is 250 meters (820 ft) tall.
Safety is the top priority
Constructing anything of these proportions takes engineering expertise. You are dealing with massive weights and forces, from the structure itself as well as from wind and seismic activity. Regarding Ferris wheels, the safety of people taking the ride as well as people and property in the vicinity must always be the top priority for mechanical engineers and designers.
Looking for the right contractor, owner of the Las Vegas High Roller, Caesars Entertainment, turned to the well-renowned construction company American Bridge, with long experience in designing and building complex structures, such as large bridges.
American Bridge writes on their website that they have “a long history taking on challenging and unique steel erection projects, often requiring unprecedented techniques.”
“A massive amount of construction engineering”
The American Bridge engineers’ design features a rim connected to a rotating hub and fixed by 112 cable spokes, made from 75-millimeter diameter locked coil cables. There are four support legs but also a single braced leg for extra support.
According to American Bridge, the project required “a massive amount of construction engineering and procedure development. By project completion, over 300 drawing sheets were prepared.”
Construction of the wheel started in late 2011, and Las Vegas High Roller opened to the public in March 2014.
High risk of devastating earthquakes
While Nevada is not subject to earthquakes on par with Alaska or neighboring California, it is still the third most seismically active state in the USA. Large quakes in California can also be felt in Las Vegas. Researchers say that the southern part of Nevada, where Vegas is located, may also face more devastating earthquakes in the future.
The risk of large and damaging earthquakes was considered when designing Las Vegas High Roller. For example, for improved stability and safety, the braced leg attached to the east end of the spindle provides lateral support in the transverse direction.
Boltight secured the braced leg
American Bridge contacted Boltight in search of a solution for tightening 16 equally spaced anchor rods that would connect the braced leg to its foundations. The construction would have to resist any tension arising from high wind speeds or seismic activity in the area.
Boltight supplied a complete tensioning solution for tightening the 16 anchor rods that secure the braced leg. It includes custom-designed tensioners, all working at 1,500 bar pressure and capable of producing 3,115 kilonewtons (kN) of force. Apart from the tensioners, Boltight also supplied high-pressure pneumatic powered hydraulic pumps, hydraulic hoses, and hydraulic manifolds.
“This solution provides double benefits. First, the equipment allowed the customer to tension the anchor rods to the pretension load required by the contract. Second, American Bridge could also perform the anchor rod pre-tensioning operation efficiently due to the equipment’s compact size, weight, and ease of setup. ”
Many advantages for the customer
Through this solution, American Bridge was able to ensure the safety of the Las Vegas High Roller's critical structure through a custom-designed bolting solution that was also accurate and time-saving.
Nick Greco, Vice President Engineering, American Bridge, concludes that, “The biggest advantages were the ease of handling, compactness, and the capacity of the equipment to achieve the desired level of stress in the rods.”