# Structural Steel Steel is how a large building goes up quickly. A frame of columns, beams, and braces is designed in an office, fabricated in a shop, delivered to a sequence, and bolted together on site by crews who do nothing else. For a compute campus the attraction is less about strength than about time: steel arrives pre-made, and a frame that assembles rather than cures lets the trades inside the building weeks earlier. > [!note] The one-sentence version > Make the frame in a factory, bolt it together in the field, and the building is enclosed while concrete would still be curing. ## Why it suits this building type A data hall wants long clear spans so rows can be arranged freely, substantial overhead load capacity for busway, cable tray, and piping, and the ability to add penetrations later as the mechanical and electrical fit-out evolves. Steel provides all three readily. It also suits repetition: a campus of similar halls can use one frame design many times, which turns engineering into a product and lets a fabricator run efficiently. ## Prerequisites - **Column, beam, and brace:** the vertical members, the horizontal members, and the diagonal members that resist lateral load from wind and earthquake. - **Moment frame against braced frame:** resisting lateral load through rigid beam-to-column connections, against resisting it through diagonal bracing; braced frames are cheaper and constrain where openings can go. - **Shop drawings and detailing:** the conversion of the engineer's design into fabrication instructions, a step whose duration frequently governs the schedule more than fabrication itself does. - **Mill order and lead time:** the rolling schedule for the sections required; unusual sizes wait for a mill run. - **Erection sequence:** the order of assembly, planned so the frame is stable at every stage rather than only when complete. - **Fireproofing:** sprayed or intumescent coating bringing the steel to its required fire-resistance rating. - **Deflection limits:** how much a member may bend under load; for a hall carrying piping and precisely aligned rows, these limits often govern member sizes rather than strength does. ## How it is built The engineer sizes the frame; a detailer produces shop drawings; the fabricator cuts, drills, welds, and coats the members and ships them in erection order. On site, a crane sets columns onto anchor bolts cast into foundations, beams are bolted up, bracing is installed, and the frame is plumbed and tightened to specification. Metal deck is laid and concrete topping poured where floors are elevated. Fireproofing follows, then the envelope. Crews proceed in a rolling sequence so that enclosure follows erection closely and interior trades can start in completed bays. The practical constraints are logistics: crane positions, laydown area, delivery timing, and the weather window. A steel package that arrives out of sequence stops a site, which is why the trailer schedule is watched as closely as the design. ## Relationships - **frames:** [[wiki/Data Center Shell|Data Center Shell]] - **paired with:** [[wiki/Concrete in Data Center Construction|Concrete in Data Center Construction]] - **scheduled through:** [[wiki/Construction Sequencing|Construction Sequencing]] · [[wiki/Prefabrication and Modular Construction|Prefabrication and Modular Construction]] - **carries:** [[wiki/Busbar Busway|Busbar Busway]] · [[wiki/Data Center Cooling|Data Center Cooling]] distribution - **built by:** [[wiki/Data Center Workforce|Data Center Workforce]] - **source articles:** [[articles/Vertically Integrating an AI Superpower from AI Factory to Citizen|Vertically Integrating an AI Superpower from AI Factory to Citizen]] · [[articles/The Gigawatt Is the New Measure of War|The Gigawatt Is the New Measure of War]] - **collection route:** [[collections/American Infrastructure|American Infrastructure]] · [[collections/American|American Collection]] ## Evidence posture - **Established:** steel frame components and lateral systems; detailing duration as a frequent schedule driver; mill lead times for non-standard sections; erection sequencing for stability; fireproofing requirements; deflection limits governing member selection in halls carrying piping and aligned equipment rows. - **Strongly indicated:** repeated frame designs across a campus materially reducing engineering and fabrication cost; developer practice is consistent and published comparisons are limited. ## Sources - Structural engineering and steel construction practice for industrial and data center occupancies, as current October 2026.