Every time I go to a Council on Tall Buildings event, I decide to delay my retirement from ENR. (I threaten to retire all the time...all talk, so far!) It's not so much because of the conference's formal presentations, though those are often informative. It's more because I have anywhere from 200 to 1,000 of the best minds in development, design and construction "at my fingertips," and I pick up all kinds of story subjects, some of which won't "ripen" for a year or two!

A case in point was last week's day-long CTBUH awards symposium in Chicago. There, I picked up news—just from networking—that will likely keep me busy for a good while. (Everyone knows that networking is the REAL reason people attend these functions.)

One tidbit came from Johannes de Jong, an ENR newsmaker this year for KONE Corp.'s ultra-lightweight carbon-fiber hoisting rope, UltraRope. (Without offering me any details, Johannes had first told me at the council's 2012 Shanghai congress that a revolutionary cabling system was coming in about a year. UltraRope was introduced in conjunction with a CTBUH London event in 2013.)

This time, in Chicago, Johannes gave me a heads up about another development—the first use, in North America, of KONE's JumpLift hoist, a six-year-old system designed to speed construction.

Johannes had first told me about JumpLift at the 2012 Shanghai congress. I wrote about it in my CTBUH congress story. In 2012, the then four-year-old system had been used in Asia and Europe, yet only approved for use in North America. (As usual, North Americans often let others take the first "leap" into a new technology!)

JumpLift is a self-climbing hoist that grows within the building by using the permanent hoistway—and a temporary machine room that "jumps" with the hoist as the building gets taller. The KONE hoist replaces the more common system of a hoist climbing up the exterior wall of the tower. 

JumpLift can be used in steel framed buildings, but is more typically used for reinforced concrete structures because, with a steel frame, hoistways are not usually protected at an early enough phase. Concrete provides a lot of the protection and the carrying needed due to the proximal shear walls in the core.

"With steel construction we need to ensure we have enough strength of horizontal beams at the machine room floors to carry the complete elevator and that makes it expensive," says de Jong.

For a 70-story building, JumpLift can shorten the construction period by 300,000 to 400,000 hours, said Johannes, KONE's chief technology officer, in 2012. The system costs more than a conventional construction hoist, but 80% of the elevator material can be permanent. "Typically, we find up to 20% improvement in efficiency, depending on the number of units used," says Johannes.

The hoist, usable when the building is 20 m up, allows the lower floors to be enclosed and finished sooner. Hoisting takes place inside the building, a safer practice that results in fewer work days lost to high winds and other bad weather. Also, cabs move more quickly—up to 800 ft per minute—reducing worker waiting and travel time. And, at construction's end, there is earlier availability of the permanent elevator.

To best reap its advantages, JumpLift planning should be done during the design phase. (All of this is according to Johannes. This is a blog, not a mutli-source construction story.)

The first North American project to use the system is One Bloor, a 75-story condominium tower in Toronto. Johannes told me about One Bloor as we flew by each other during a coffee break at the symposium. (Though JumpLift was a topic at the most recent CTBUH Shanghai conference, I didn't make it to Shanghai this year.)

Stayed tuned to ENR to follow the "growth" of One Bloor. We'll see if JumpLift rises to its potential.