60-storey skyscraper in Boston has a mysterious defect Architecture

The highest skyscraper in Boston, US, John Hancock Tower, was built in 1972 to the year. A month after the completion of one of its windows, a huge glass panel size of 1, 20 m 3, 35 m, for some unknown reason, it fell out and broke. Within a week after the event from the building in the same way it has fallen off more a dozen windows.

Development company came to the conclusion that the use of poor quality windows, and replaced in the building of all 10,334 windows. But the windows continue to fall until now. We put forward a different version about the causes of this phenomenon. We assumed that the windows burst on the temperature difference inside and outside the building, especially at high levels. Even suggested that the skyscraper with the times "twisted" around its axis under the influence of constantly blowing winds in this place. However, no one was able to give a clear answer to the question, why did John Hancock Tower continues to lose the window.

The root of the problem was in the framework of insulating glass in glass, and in a way junction frame with glass. Durable materials, work fine in a relatively small glass units, proved to be unsuitable for large panels of John Hancock Tower: the difference in the coefficients of thermal expansion leads to the accumulation of microcracks on the perimeter of the frame; under the load of the wind glazed eventually crumbled.

For the safety of passers-by, John Hancock has hired two employees, whose job was to inspect the windows, look for cracks and prevent the possible loss.

via factroom.ru