The 1960s and ‘70s saw the American city explode in a new round of reaching for the sky. Simultaneous challenges emerged as contractors worked to fulfill the visions of architects and developers: speed with accuracy. Sundt developed many innovations to help address these challenges by bringing the art of slip forming from grain silos to high rise cores, and became a preferred contracting partner in major metropolises like Atlanta, Dallas, Denver and Phoenix.
The biggest difficulty with vertical slip form construction is controlling vertical and horizontal tolerances. Even sunshine affects a core’s alignment – a core can shift six inches on the sunny side. Early on, the biggest challenges were constructing cores that were almost perfectly straight, often 600 to 700 feet tall, manufactured with a “liquid,” and doing it all safely and quickly. Existing technology and methods simply weren’t accurate enough for the new era of ambitious slip form projects.
Sundt introduced or advanced the following:
• Laser alignment systems
• Cranes carrying forms riding on sleds
• Fiberglass formwork
• Enhanced methods to float finishes as they emerged from the form
Norwest Tower, Tucson; IBM Tower, Atlanta; Marriott, Denver