Cincinnati Museum Center Union Terminal completes first full structural restoration in 85-year history

. November 13, 2018

CINCINNATI – Over the past two-and-a-half years, more than 2,400 craftsmen worked over 900,000 hours to turn back the clock on Union Terminal. The historic undertaking is the first full structural restoration in the National Historic Landmark’s 85-year history and, with its completion, preserves the building’s past and secures its future for generations to come.

When it opened in 1933, Union Terminal was hailed as a masterpiece, a temple to transportation. It was built to handle 17,000 passengers a day, a number that doubled as troops traveled to and from war during World War II. Despite the fanfare that accompanied its opening, train travel was on the decline and the station closed in 1972. For the next 18 years, Union Terminal went through phases of vacancy and occupancy before it became home to Cincinnati Museum Center in 1990. In those eight decades, the building suffered compounded the damaged caused by water penetration over the years. The result was a National Historic Landmark in need of dire repair. In 2014 the National Trust for Historic Preservation listed the building on its list of the “11 Most Endangered Historic Places” in the United States. The beloved icon needed significant restoration to remain functional.

The community voiced their support of Union Terminal’s major fix in November 2014 with the passage of a five-year, one-quarter of one percent Hamilton County sales tax. The estimated $175.7 million the sales tax would generate was the catalyst for the start of Union Terminal’s $228 million restoration.

Turner Construction Company was selected as the construction manager and GBBN Architects served as the architect and design lead on the project. Their goal was to address structural steel and the exterior envelope that had been damaged by water penetration and natural deterioration over eight decades while also updating mechanical, electrical and plumbing systems to make the building more efficient to operate. After more than a year of probes, analysis and design work, construction kicked off in July 2016.

Union Terminal’s iconic fountain and plaza, so critical to the historic fabric of the building, were carefully surveyed and removed over a period of fourth months, exposing the roof deck below for repairs. After the plaza demolition, crews waterproofed the plaza’s 120,000 square feet using tar heated to a temperature of 375° applied over a thin fabric sheet and then covered with a plastic liner, insulation board and gravel. The waterproofing prevents future water penetration into the museum spaces and structure below.

With waterproofing complete in October 2017, the first of 56 concrete trucks rolled onto the plaza to begin pouring the basin of the 8,000-square-foot fountain. For the next five months, 450 cubic yards of concrete recreated the scalloped cascades and iconic shape of the fountain, paving the way for the application of a two-part polyurea waterproofing and a finishing layer of green terrazzo with a rustic finish, matching the original look of the fountain.

Beneath the fountain and plaza, crews spent six months from November 2017 to April 2018 addressing steel girders damaged by decades of water penetration through expansion joints above. To address the damaged steel in the ceiling of the mezzanine level, eight six-ton, 40-foot steel beams were brought in and customized on site. Using steel gantry systems, the steel beams were hoisted from the lower level to the mezzanine and then glided to their desired locations using compressed air. The installation of the eight beams required an additional 20 tons of steel to build gantry systems and temporary scaffolding.

On the face of Union Terminal, crews reinstalled the clock after nearly a year of repairs. The hands were removed and restored, complete with new red neon lighting along their edges. New red and amber glass were installed across the clock’s 18-foot face and the internal gears and mechanisms have been updated and repaired by the Verdin Company to ensure the clock stays on time.

Over 225,000 square feet of limestone, brick, terracotta and concrete have been cleaned and repaired. Over 35,000 linear feet, nearly six and a half miles, of silicone caulking has been removed and replaced with mortar closely matching that of the original used on the building, which will also help prevent water from penetrating the masonry into the steel structure behind it. That structural steel was exposed on every vertical and horizontal edge for treatment. The steel was cleaned and painted with a zinc primer and two layers of acrylic paint to prevent future oxidation by stopping water from penetrating to the steel itself.

One of the most significant masonry and structural projects was the rebuild of the curved drum walls that sit just beneath Union Terminal’s half dome. The lack of expansion joints and outdated construction techniques resulted in poor thermal expansion capabilities, causing the wall’s brick and steel to slowly move away from each other, damaging the wall system. Between January 2017 and February 2018, the terracotta and brick walls were completely removed and rebuilt, replacing the interior terracotta wall with a concrete block wall with support steel woven throughout and finally covered with over 17,500 original exterior face brick.

Another major masonry project was rebuilding the station’s west wall, which was built in the 1970s after over 450 feet of the original concourse was demolished. The wall was completely disassembled, exposing original structural steel that has since been cleaned and treated. Masons then rebuilt the wall from the structural steel outward with a concrete block wall supported by steel woven throughout before exterior brick was installed as the final step. This work took place three stories above and just feet from an active rail line.

For more information, visit www.cincymuseum.org

Category: Museum News

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