FlexArm Counterbalancing NYC SkyScrapers

New York City is shooting up towards the sky, bursting with multi-millionaires in search of the penthouse room with a view, but developers are rapidly running out of ground space to build on.

As available land becomes more scarce in all major cities, there is a huge incentive to build taller, thinner apartment buildings on tiny lots. The higher and skinnier a building gets, the more it tends to sway in the wind.

A typical 1000' tall building will sway

6" in 50 mph winds, and in 100 mph winds, they sway as much as 2'.

Such small movements don't necessary present safety hazards, and are often imperceptible, but they can have the same effect as the gentle swaying of a cruise ship... seasickness.

"Unless you're a super-sensitive person, you're probably not going to feel it, but if you're building a luxury apartment, you have to think about the comport of every buyer." says Izak Senbahar, developer of an 821-foot TriBeCa Tower.

And since most pent-house dwelling occupants don't want to wear seasick bands in their own home, structural engineers have created a system to stay the sway.

A tuned mass damper is a counterweight system made of steel or concrete, and can weigh anywhere from 300-800 tons. It is mounted towards the top of the building, and acts like a massive shock absorber, pulling the building back towards its original position whenever high winds blow.

A recent customer of ours, Frontier Steel, a division of Samuel, Son & Co. , supplied the finished plates to build this giant counterweight, and used the FlexArm GH-60 Hydraulic Tapping Arm to create parts for the massive pendulum. They tapped 2" holes in 3" thick steel plates. Russ Kolesar says "We tapped approximately 800 holes and did not break one tap. The tapping arm has exceeded every one of our expectations."