Sphere Las Vegas

In every one of these substructures that are critical to Sphere, CAST CONNEX steel castings provide an optimized solution offering enhanced tolerances and simplified constructability.

‍

‍

EXOSPHERE

‍

The venue's exosphere, the world's largest spherical structure rising 366-feet (112-meters) from its base and measuring approximately 520-feet (158-meters) in diameter at its equator, is an assembly of straight tubular members framing between 368 custom cast steel nodes ranging in weight from 1.6 to 7.2-tons (1.5 to 6.5-tonnes) each.

The cast nodes utilized in the exosphere provided tonnage savings in the connections and facilitated rapid and precise field assembly and erection of the structure. The node configuration developed by CAST CONNEX reduced the number of bolts required in the exosphere by a factor of 4- to 8-times and reduced the connection tonnage by approximately 60-percent. The nodes also provide CNC-level geometric tolerances and define the Sphere’s shape. Straight segments of hollow structural sections (HSS) or pipe members, with square-cute ends, span between the nodes.

Not only would conventionally fabricated nodes have been less efficient from a tonnage perspective, they would not have been nearly as precise, as the nodes would have been subject to significant distortion from welding, compromising dimensional accuracy and alignment. The cast nodes also incorporated built-in features to accelerate field assembly and to aid in geometric control during ground assembly and erection.

‍

IMMERSIVE SURFACE

‍

The construction of the structural steel backup to the venue’s wraparound interior LED screen – the highest resolution LED screen on Earth – was enabled by nearly 1,000 custom cast steel components. 

The interior wraparound LED screen (the Immersive Surface) – having a resolution over 100-times that of a high-definition television – is made up of hundreds of LED array panels which must be installed to exacting tolerances. The adjacent panels must be within ± 20-thousandths of an inch of their nominal spacing lest light constructively interfere (creating white lines between the panels) or be disperse (creating black lines between the panels). 

The cast steel nodes CAST CONNEX conceived and supplied to the structural backup to the Immersive Surface are a cornerstone of the fabrication and erection approach – offering a means to modularize the steel framing, to enable precision shop fabrication and site assembly, and to control geometry during fabrication and erection. Features built into the nodes were also key to monitoring the geometry of the frames during fabrication and erection – a critical requirement, given the need for precision well beyond standard steel construction tolerances to achieve the 16K resolution of the wraparound immersive screen on the venue’s interior. 

‍

EXTERNAL LED TRELLIS

‍

Nearly 10,000 CAST CONNEX Diablo Bolted Splice (DBS) connectors support field-bolted assembly of the tubular steel backup structure to the world's largest LED screen on the venue’s exterior. With 580,000-square feet (54,000-square meters) of fully programmable LED, it is an iconic landmark in the Las Vegas skyline. 

The use of CAST CONNEX Diablo Bolted Splice connectors for the exterior trellis was critical in providing efficient, compact/inboard bolted connections necessary for the exterior LED display. The connections also accommodated the manufacturing tolerances of the roller-bent 7.5-inch (191-millimeter) outer diameter HSS sections used to make up the spherical trellis. 

‍

PRECONSTRUCTION SUPPORT

‍

During the design phase, CAST CONNEX provided Severud with conceptual designs for the cast steel nodes. This effort resulted in the cast nodes being shown as one of two connection options in the structural steel bid package. Ultimately, W&W | AFCO Steel chose to proceed with the cast node option as they deemed the cast nodes to be the only viable option for successfully fabricating and erecting the exosphere. 

Additionally, CAST CONNEX was part of a collaborative design-assist effort relative to the structural backup for the Immersive Surface. It was during that process that CAST CONNEX developed the cast node designs along with the integrated fixturing scheme and survey features used in the fabrication shop and in the field that were crucial to achieving the precision required in the structure. 

‍

‍