2006 PALLADIO AWARDS

Sympathetic Addition
WINNER: ARCHITEXAS

Now the Bells Toll

PROJECT: Tower addition to Cathedral Santuario de Guadalupe, Dallas, TX
ARCHITECT: Architexas – Architecture, Planning and Historic Preservation, Inc., Dallas, TX; Gary Skotnicki, principal in charge; Richard Martratt, project architect; Jay Firsching, David Chase, Carrie Zaboroski, Elizabeth Cummings, Jeff Cummings, associates
GENERAL CONTRACTOR: Andres Construction Services, Dallas, TX
STRUCTURAL ENGINEER: Jaster-Quintanilla, Dallas, TX; Steven, H. Lucy, PE
LIGHTING DESIGN: Lindsley Architectural Lighting; Alan Lindsley, principal
ELECTRICAL ENGINEER: OLA Consulting Engineers, Dallas, TX

The Sacred Heart Church in Dallas, TX, now the Cathedral Santuario de Guadalupe, was designed in the 1880s by noted Galveston, TX, architect Nicholas J. Clayton with tall towers on the south façade. It was completed in 1902, but the spires were not built at that time, presumably for financial reasons. The bases were there, but they were capped with simple wood-framed hipped roofs.

A later, simpler design by Clayton incorporated one tall tower and a shorter one, and a still later third design in 1907 featured a Beaux-Arts tower with a clock. Now, after more than 100 years, the church has finally completed the towers, the tallest housing a 49-bell carillon and clavier, thanks to a $4.7-million project and the design efforts of Architexas of Dallas, TX.

“The new design is an adaptation of Clayton’s second version,” says Jay Firsching, preservation specialist at Architexas. “We felt like the middle design most closely matched the style of the building as it was intended to be constructed,” he explains. “These are also the more detailed and developed of Clayton’s drawings, so they were interpreted and adapted in designing the new towers.

”This project presented a number of design and engineering challenges. First, the towers had to be compatible with and enhance the original historic building. Secondly, the taller of the two had to support the new quite-heavy carillon requested by the diocese. The new spire adds 135 ft. to the original base to reach a height of 219 ft. from the ground floor (224 ft. from grade) and supports the 49-bell carillon system weighing 49,000 lbs. and a clavier (keyboard) to play the bells. Manufactured in the Nether-lands, this particular carillon includes 45 static bells, the largest weighing 2,200 lbs., and four swinging bells, the largest weighing 9,400 lbs. It was quite a challenge to hoist these bells into place, with the largest and highest bells located 146 ft. above street level.

“We had to interpret the original 1/8-in. scale drawings based on the existing detailing of the cathedral,” says Gary Skotnicki, Architexas’ principal in charge, and the person charged with adapting the historic design. “The original structure is load-bearing solid masonry with interior timber framing. We had to determine the best way to detail and construct the new tower addition to fit within Clayton’s intentions while meeting today’s building codes.

”To accommodate the massive weight of the bells as well as the new 224-ft. west tower itself without adding stress to the original 106-year old building, Architexas and the engineers determined that the structure would have to be supported from the ground up. “The base of the tower is about 20-ft. square, with 28-in.-thick load-bearing masonry walls on a corbelled masonry foundation extending 4 ft. below grade,” Skotnicki explains. “The design team decided that the new tower extension should stand independently from the existing masonry base, but appear to be part of the existing structure, as if the building had been originally completed all the way up to the spire and cross.

”These goals were accomplished by excavating a 35-ft. square around and inside the existing structure to the bottom of the footings. Four piers, each 18 in. in diameter, were then drilled to a depth of 56 ft., protruding 8 ft. into the underlying limestone substrata. Two 24x54-ft. slots were cut through the corbelled footings and each face of the tower base. Reinforcing steel cages made up of #11 rebar were placed around and through the existing masonry footings. Seven thousand pounds of concrete were then poured, integrating the old and new foundations. The resulting pad contains 90,000 lbs. of steel and was designed to carry four 14-in. square columns to support the new tower extension above.

Once the foundation was in place, the steel inner frame was inserted into the tower, which had been gutted. The roof was removed and prefabricated steel structural sections were hoisted, one at a time, over the top of the existing masonry walls and lowered carefully down into the tower. There was only ½-in. clearance from the existing walls. The fourth of these sections brought the structural frame above the existing masonry and the fifth section formed the 36-ft.-tall bell chamber. The final prefabricated steel section was erected and welded on the plaza and hoisted as one assembly to form the dormer level. The last piece was the aluminum-framed, copper-roofed steeple. It was constructed offsite by Campbellsville Industries of Campbellsville, KY, shipped to the site and lifted into place.

“Most of this work was done at night because we weren’t allowed to close any of the major streets during the day,” says Richard Martratt, project architect, Architexas, “and we had to use large cranes to lift the sections into place. After each section was lifted into place in the tower, we would work on it for a few weeks. It took quite a while to weld those sections in place and to get ready for the next ones. Plus you had the interior elements – several bell levels and various support brackets and also the stair itself – that had to be welded in place.

”Hoisting the bells into place was another challenge. The contractor, Andres Construction Services, Dallas, TX, used a combination of systems. A hydraulic platform scaffold system capable of supporting 16,000 lbs. with a climbing speed of 100 ft. every 50 min. did part of the heavy lifting. The platform scaffold was also equipped with a material hoist with a lifting capacity of 2,500 lbs. and a travel distance of 80 ft. A cantilevered trolley beam and pneumatic trolley hoist with a lifting capacity of 10,000 lbs. was installed above the upper bell chamber. These systems were used together to carefully lift the bells into place in the two bell chambers.

“Hoisting the bells was difficult because we had to snake them through the steel structure,” says Martratt. “Lifting a nine-ton bell and snaking it through the structure is quite a feat. We built some lifts on the outside of the tower that were used to transport them to a certain height, then we used a system of levers and pulleys to get the bells into exact position.” This work could be done during the day because it didn’t require cranes and the streets didn’t have to be closed. Those same platforms were used when cladding the building and doing other exterior construction.

At one point, Martratt points out, the vibration of the bells was a big issue. “When we got the bells installed and began to ring them for the first time, the whole frame began to sway,” he says. “We were getting about ¾-in. vibration. We got the engineers involved again to take another look at it. We figured out that the frequency of the vibration was the same as the steel frame, so it excited the steel frame, causing it to move when the bells rang.” The problem solved itself when the building was loaded with masonry. The primary materials used to clad the new section of the spire were red hard-fired brick, cast stone and copper. These were selected to blend with the historic structure, according to Skotnicki, “to fit seamlessly into the historic building. It was a bit of a challenge to match the original brick, but we came close.

”The shorter tower was a simpler project. It also had a hipped roof, which was removed and replaced with a copper-roofed steeple from Campbellsville Industries. This added almost 41 ft. to the tower, bringing the height to 102 ft. “We did some exterior repair work, but we didn’t have to do the foundation work because the tower was not increased in size,” Firsching notes.

Construction started in June of 2005 and was completed in November of 2005 without disrupting the normal services and operations of the cathedral. The new spire more than doubles the height of the building and it finally fulfills the goals of the original design of the cathedral. In addition, it allowed the church to add the massive carillon, fulfilling the diocese’s goal of bringing a level of prominence to the cathedral. Skotnicki points out that this is the largest carillon (by one bell) in Dallas and the second largest in Texas, second only to the one at the University of Texas in Austin.

The Cathedral Guadalupe serves one of the largest cathedral congregations in the United States, with an average Sunday mass of almost 10,000 parishioners. The new towers are just one phase of a comprehensive set of improvements being undertaken for the cathedral and its surrounding buildings and plazas. “We began working with the diocese in 1995,” says Skotnicki, “when Architexas completed a master plan prioritizing the work into manageable phases that minimize the impact of construction on daily services.

”Previous work included the integration of new mechanical systems into the building, redesign of the altar and exterior restoration of the building’s two primary entry bays. Future phases will focus on the plazas, restoration of the sanctuary, and completion of the exterior restoration.

“This is the most dramatic of the work so far,” Skotnicki says. “Nicholas J. Clayton would have been very happy with the new addition. His grandson and great grandson participated in the groundbreaking and the dedication. Everyone is happy with it.” – Martha McDonald

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