More testing before repair decisions about Naperville bell tower
The iconic Moser Tower in Naperville is about to undergo a third set of structural tests.
Officials have been keeping an eye on the stability of the riverside spire since spring 2017, when a consultant's report identified issues with cracked concrete, corroded steel and a leaking plaza.
Although the structure containing the Millennium Carillon is considered safe, the Riverwalk Commission has been working to form a recommendation about whether the tower should be repaired, improved or taken down.
Commission members last month expressed early support for repairing the tower that's become a fixture of the Naperville skyline. But officials also have approved another set of tests to help inform the decision.
Bill Novack, the city's director of transportation, engineering and development, said new testing in a $35,000 addition to a contract with consultant Engineering Resource Associates will include crack modeling and mathematical structural modeling of how the structure should be handing stress and strain.
The mathematical predictions then can be compared to actual conditions observed in reports issued in 2017 and in March, Novack said, to determine if the tower's materials are behaving as expected.
Novack said conducting these additional tests will give commission members -- and later city council members -- all the information they need to decide on the next steps for the tower.
"As large of a structure as this is ... this is the prudent thing to do," Novack said about the testing. "And so we will do it."
If officials decide to preserve the 19-year-old tower, instead of tearing it down for an estimated $600,000, they could do so in phases or all at once, following plans that could cost from $1.3 million to $2.4 million, according to the report issued in March.
That report determined the 160-foot-tall structure is in better condition than originally feared and is in "a proactive repair state where work and repairs can be designed to slow down or prevent additional issues."
Novack said the crack modeling and mathematical structural modeling are expected to be complete by August, so Riverwalk Commission members can begin discussing results in late summer or early fall. Novack said the timeline puts the commission on track to make a recommendation to the city council in time for repairs to be considered during talks about the capital improvement plan for the 2020 budget.