Sears Tower Lecture Notes

Introduction

• Over 25,000 people visit the Sears Tower daily.
• Uses 104 elevators, including double-decker ones, to service 110 floors.
• Tallest building in North America; previously the tallest in the world until 1998.

Observations and Views

• Rises 1,450 ft above Chicago.
• Skydeck offers views up to 50 miles, including parts of Illinois, Indiana, Wisconsin, and Michigan.
• Attracts over 1 million tourists annually.
• Features unique elevators, two of which are among the fastest, traveling at 1,600 ft/min.

Building Specifications

• Total area: 4.5 million sq ft, equivalent to the length of five football fields.
• 2,232 steps to the top; 796 laboratories within the tower.
• Facilities include offices, dining clubs, conference spaces, a post office, retail stores, and restaurants.
• Requires significant maintenance: 110 janitors, 100 security guards, 25 engineers, and more.

Maintenance and Operations

• 50,000 miles of electrical wiring and 25,000 miles of plumbing.
• Features advanced window washing technology, capable of washing 16,100 windows year-round under specific conditions.
• Engineers maintain a comfortable temperature across different floors, monitoring HVAC systems.

Historical Context

• Built in 1968 for Sears Roebuck and Company, which was the largest retailer at the time.
• The building was designed as a statement of dominance, needed for expansion due to post-WWII growth.
• Origins of Sears date back to a mail-order business started by Richard W. Sears in 1887.

Design and Architectural Innovations

• Designed by Skidmore, Owings & Merrill (SOM), featuring the innovative bundled tube system.
• The structure has nine bundled tubes that reduce the need for interior support columns, allowing larger floor spaces.
• The design also allows for attractive leasing options by creating smaller upper floors.

Construction Process

• Groundbreaking in August 1970; foundation involved deep excavation and concrete matting.
• Steel columns were prefabricated, allowing for efficient assembly on site, achieving two floors constructed per week.
• Weather conditions posed challenges; construction was often halted due to high winds and low temperatures.

Completion and Post-Construction Changes

• Topped off ceremoniously on May 3, 1973.
• Noted for its unique leaning structure (leaning 6 inches to the west).
• Initially, 40% of the space occupied by about 8,000 Sears employees; later converted to tenant spaces.

Modern Transformations and Security

• After Sears vacated, the building underwent renovations to attract new tenants, including improved access and security measures.
• Post-9/11 security upgrades included advanced systems for tenant safety.

Current Status and Legacy

• Continues to be a symbol of Chicago, holding various architectural and broadcasting records.
• Remains the tallest building in North America, with antennas extending above its roofline.
• The building reflects the ambition and innovation of its creators and retains a significant place in Chicago's skyline.