Sky-High Solutions by Dearborn

Understanding the Challenges

The project’s complexity was heightened by its location: it was set above the eight-story section of the building, sandwiched between the 9th and 12th floors, amidst the bustling environment of an operational hospital. At Dearborn Companies, in collaboration with other top-tier contractors from metropolitan Chicago, we took on this challenge with a commitment to safety, timeliness, and budget compliance.

Dearborn Companies, with 67 years of experience in engineering and nondestructive examination, played a pivotal role in devising strategic solutions for this project. A key recommendation was the installation of a 25-ton carry-deck crane on the 8th-floor roof to facilitate the construction process. While the idea was straightforward, its implementation demanded thorough structural analysis, extensive preparation of the roof, and careful planning of the lifting operation.

Engaging an All-Star Project Team

For this ambitious project, we brought together an exceptional team comprising highly regarded companies from the metropolitan Chicago area. Dearborn Companies contributed its specialized expertise in construction engineering and heavy-lift consultation, collaborating closely with Power Construction, the general contractor, and other key project partners. Our responsibilities encompassed a range of critical activities, including planning, scanning, and analysis, all aimed at guaranteeing the project’s success over its 21-month duration.

Choosing the Right Cranes

Michael T. Walsh, President of Dearborn, played a pivotal role in the critical process of crane selection for the project. After thorough consideration of various factors, our team determined that a combination of a large all-terrain crane and a 25-ton carry-deck crane would most effectively meet the project’s specific requirements. This decision underscored a collective effort, embodying our company’s
fundamental commitment to teamwork and collaborative problem-solving.

Planning and Prepping

The intricate complexities of the project demanded meticulous planning as the cornerstone of success. Dearborn conducted an extensive structural analysis of the 8th-floor section, encompassing both interior and exterior aspects, to devise a support framework capable of sustaining the crane, mats, and materials.

Working in concert with our project partners, we engineered a mat system specifically designed to distribute loads evenly across the building’s structure. Additionally, we made certain that the mat was robust enough to endure any potential impacts from steel beams, adhering strictly to the hospital’s stringent safety standards.

Delivering Positive Performance

The project culminated in three months of precise planning, resulting in a remarkable execution. The carry-deck crane flawlessly performed all necessary lifts, constructing the walkways while ensuring minimal stress on the roof. During this phase, it managed to lift and place 100,000 lbs. of steel, over 100 cubic yards of concrete, and 3,000-lb. pallets of curtain wall glass.

A crucial aspect of the project was the vigilant monitoring of roof-deck deflection. Impressively, the roof deflected no more than a quarter of an inch, even during the placement of 4,000-lb. beams, underscoring the efficacy of our planning and design.

This endeavor showcased the collaborative excellence of Power Construction, Chicago Steel, Central Contractors, Sterling Lumber, Northwestern Memorial Healthcare’s facility planning safety team, Klein & Hoffman, and Dearborn Companies. It was a vivid demonstration of our collective capacity to tackle unique challenges, innovate solutions, and successfully manage complex projects within stringent parameters.

This project was profiled in Crane Hot Line

Read the article in the September, 2021 issue of Crane Hot Line