Sears Tower Lecture Notes

Overview of the Sears Tower

Daily Visitors: More than 25,000 people walk into the Sears Tower daily.
Elevators: 104 elevators, some double-decker, transport visitors and workers to 110 floors.
Height: Rises 1,450 feet above Chicago; tallest building in North America until 1998.
Observation Deck: "Sky Deck" offers views up to 50 miles, covering Illinois, Indiana, Wisconsin, and Michigan.
Annual Tourists: Over 1 million tourists visit the Sky Deck each year.

Elevator Speed: Fastest elevators travel at 1,600 feet per minute, reaching the 103rd floor from the basement in about 60 seconds.
Size: Contains 4.5 million sq ft of space, spans close to five football fields.
Maintenance: Requires 110 janitors, 100 security guards, and 25 engineers for upkeep.
Utilities: 50,000 miles of electric wiring, 25,000 miles of plumbing, and 145,000 light fixtures.

Window Cleaning: Automated systems for cleaning 16,100 windows. Operated year-round, weather permitting.
Temperature Control: Engineers monitor HVAC systems on specific hidden floors.
Refrigeration: Five chillers equivalent to 4,800 tons of refrigeration supply cooling to the building.
Power Backup: Two standby generators can power 200 homes; the building has never lost power.

Sears Robuck Company: Founded in 1887; grew rapidly post-World War II; needed a large headquarters.
First Headquarters: "Great Works" established in Chicago; largest commercial space in the U.S. at that time.
Building Decision: In 1968, Sears decided to consolidate under one roof due to growth projections.
Site Selection: Chose a site for its accessibility and public transport links.
Architectural Team: Skidmore, Owings & Merrill (SOM) led by Bruce Graham and Fazlur Khan.

Bundle Tube System: Innovatively designed using bundled tubes for structural support, allowing large office spaces.
Floor Plans: Nine tubes in a 3x3 arrangement, with varying heights for different floors.
Design Inspiration: Initial plans were for a large square building; the final design was more dynamic.
Topping Out Ceremony: Held on May 3, 1973, with a final beam signed by 15,000 workers.

Construction Issues: Faced mishaps, including a cable drop that damaged a taxi but resulted in no injuries.
Weather Delays: Construction was affected by wind, snow, and extreme temperatures.
Speed of Construction: Iron workers set floors at an impressive rate, overcoming logistical challenges.

Completion: Finished in 1974, it was under budget and on time.
Initial Occupancy: 40% occupied by Sears employees; innovative office design.
Challenges: Employees struggled with the transition from horizontal to vertical office layouts, impacting collaboration.

Sears Departure: Sears moved out in 1990, leading to renovations for new tenants.
Post-9/11 Security Upgrades: Enhanced security measures implemented after the September 11 attacks.
Television Antennas: Upgrades in 2000 with antennas extending the height of the building.
Current Status: Remains a symbol of Chicago and the tallest building in North America, despite new tall buildings arising.

Legacy: The Sears Tower represents a significant architectural achievement and cultural landmark for Chicago.