The Fort Worth Museum of Science and History has served many generations. But however loved it was, it was time for a new museum. In November 2009, the new Fort Worth Museum of Science and History replaced the existing 1952 museum on the same site.

Careful collaboration and design achieved the architectural vision of a glass box atop an open interior space as the museum’s entry. courtesy of Datum Engineers

The museum includes 115,000 gross square feet of one-story and two-story exhibit spaces, classrooms, public places, and dining areas.

The Urban Lantern
The main entrance — called the Urban Lantern — is the pride of the museum. The proportions and interior volume of the space is tall, open, and impressive. Datum Engineers, Inc. designed the structure to keep the architectural vision alive. Coordination between the structure, interior architecture, and glass manufacturer was truly a team effort — careful computer modeling and structural analysis was conducted to ensure that the framing system and brick supports would perform as expected.

Structural design— The basic approach was to create a braced tower with an open interior. Usually a tower would have horizontal x-bracing or floors to prevent racking and distribute lateral loads, but this was not an option. Instead, the team used the building’s adjacent low roof diaphragm at El. 19 feet and a 5 foot 10 inch-wide reinforced concrete slab on composite deck at the tower’s second level at El. 39 feet to provide racking strength. It was basically a floor slab with a big hole in the middle of it. Additionally, the roof corners at El. 56 feet had concrete slabs to enhance stiffness. The calculated stresses in the slabs were below 75 psi. Full height x-braces at the corners of the tower included girts at 10 feet vertical spacing ties the tower together and provides connection points for the brick support system.

The exterior brick was supported by a unique framing system specifically designed to eliminate visible horizontal kickers into the interior open space. Vertical 5x5 tubes spaced at 4 feet on-center support the brick lintels. The 12x6 tube girts are designed to resist the moments and reactions induced by the eccentric brick loads at each level.

Glass box— The distinctive feature of Legorreta’s Urban Lantern incorporated a glass box at the top. Datum conceived the structural concept and design of the glass box at the top of the tower. Then a proprietary manufacturer, Novum Structures LLC, implemented the design and built the glass box. Novum is a one-source, full-service company that designed and fabricated nearly all components of the tower’s glass box. Novum’s glazing and steel connections were integrated into the architecture through close coordination, producing the effect Legorreta envisioned. The loads calculated by Novum’s engineer were provided to Datum to include in the overall building model.

This state-of-the-art glass system included unique proprietary glass connections and expansion joints designed specifically for the Fort Worth area. The end result accomplished the architect’s vision.

The design and construction team performed within a very tight schedule requiring a fast-track process. Good coordination was critical because the structural design went ahead of the architecture in some cases. However, the design and construction team worked very well together to solve these issues before they could become major problems.

Legorreta & Legorreta was the design architect with Gideon Toal as the architect of record. The Projects Group managed the design process and served as the owner’s representative during design and construction phases. The consultants included: Datum Engineers as the structural engineer and engineer of record; Blum Consulting Engineers for mechanical design; Kimley Horn for civil design; and the Mesa Design Group for landscape design.

Jeff Koke, P.E., is studio manager at Datum Engineers, Inc. He has 20 years of experience as a structural engineer and project manager, and can be reached at jeff@datumengineers.com.