Twin crescent towers rising 211 m above Qatar's marina — an architectural homage to the crossed scimitars of the national emblem, engineered to read as one continuous gesture.
The Katara Towers programme asked for a twin-tower complex that read as a single sculptural form rising from a shared podium — a crescent silhouette directly inspired by Qatar's national emblem.
The challenge: hold the crescent geometry while serving 500 hotel rooms, residential floors, retail and a ballroom across 300,000 m². Metalyol engineered, fabricated and erected the structural steel skeleton that gives the crescent its discipline.
Inspect the spec sheetThe structural skeleton answers a unique loading problem — each tower curves in two planes simultaneously, so floor plates rotate as they rise and lateral loads stack asymmetrically against the wind.
At this height and footprint, the lateral system carries far more load than gravity. We engineered the primary frame in S460 NL plate — higher yield, less section, less weight on the foundations.
Most tall buildings stack identical floor plates and let the structure repeat. Katara doesn't. Each floor plate is a slightly different shape — rotated, scaled, offset — because the silhouette has to read as a continuous crescent from any approach.
Practically, that meant no two columns were exactly alike, no two floor beams identical, and every connection was a one-off. Standard fabrication economics didn't apply.
We modelled every column and every beam as a parametric instance — same family, different angles — then drove our CNC plasma and beam-saw cells directly from the BIM output. No drawings on the shop floor; the steel knew its own geometry.
On site, the towers were lifted floor by floor, with a real-time survey loop that fed measured deflections back into the next floor's setting-out. Final crown verticality measured under 1/4000 — well inside the 1/2000 spec.
Architectural surface translated to a structural BIM with per-floor geometry.
Wind, seismic, dead & live load envelopes with dynamic-response checks.
S460 NL plate cut and welded to per-element parametric drawings.
Floor-by-floor lift with continuous survey-feedback for crown verticality.
Spires installed, unitised façade hung, structure handed over for fit-out.
From a single mill order to a full turnkey lift — one team owns the path from drawing to surveyed structure.