Naperville carillon tower 'structurally sound,' but repair costs unknown
The tower holding the Millennium Carillon in Naperville is in better shape than initially feared, according to a newly revised report, city officials said Thursday.
But officials still don't know how much it might cost to make the necessary repairs to the Moser Tower along the downtown Riverwalk.
The draft addendum to a 2017 report determined the tower is "structurally sound, in serviceable condition and can be repaired," said Geoff Roehll, chairman of the Riverwalk Commission, which oversees the city-owned structure.
The draft essentially found that despite corroded steel, cracking concrete, deteriorating sealant and a leaking plaza identified in the 2017 report, the internal structural steel is in good shape and showing little signs of damage.
Conducted this spring by Engineering Resource Associates of Warrenville and several subcontractors under a $118,000 contract, the draft involved materials testing, an architectural review of drawings from 1999 and an assessment of durability.
"The common theme is that everything is in the realm of repair," said Brian Dusak with Engineering Resource Associates.
What remains unknown from the draft report is the cost of repairs that could extend the life of the 160-foot-tall tower built in 2000 and completed in 2007.
Several options identified last year - including enclosing the lower 72 feet to match original designs and shielding structural components from the weather, completing some structural fixes but leaving the entire height unenclosed, conducting only basic maintenance, or tearing down the tower - all remain feasible, said Bill Novack, director of transportation, engineering and development.
But city officials now say they're thinking positively about the potential to fix and preserve the spire.
"I feel much better than I did with the initial report," Novack said, "because a lot of our unanswered questions are now answered and we can start looking in greater detail."
Dusak said consultants will work with members of the Riverwalk Commission, as well as a subgroup called the planning, design and construction committee, to determine likely courses of action and estimate costs. The 214-page draft, described as "very technical," identifies numerous potential repairs that could improve weatherproofing, drainage, corrosion of steel and cracking of concrete.
"This would be regarded as a proactive repair program, where works would be designed to slow down or prevent issues from occurring," Engineering Resource Associates wrote in the draft.
Subcontractor Brush Architects of Chicago said the tower's issues result from a combination of factors, including "the change of the design of the tower from partially enclosed to unenclosed, deficiencies in the design of the original structure at key failure locations, subsequent retrofits and repairs, and poor material choices as in weather-protective coatings."
Still, the news that the tower is not in imminent danger of severe damage means city officials plan to proceed with caution. Roehll said there is no timeline for when the Riverwalk Commission might give its opinion to the city council, the eventual decision-making body, about what should be done with the tower.
"I don't see us making a recommendation for quite some time," Roehll said. "We want to get it right. We want to understand what the cost implications are."