During the spring, summer, and fall, the windows of the World Trade Center from the 9th to the 106th floor are always being washed.
The winter season is prohibitive because of heavy winds and freezing temperatures. A huge automatic window washer for each tower, resembling a crane, is operated by one man standing on the roof.
Using remote control, he sends the machine over the side, down steel runners, past a “bay” or column of windows spanning 97 floors. Each tower has 248 bays and more than 22,000 windows. Cleaning at lightning speed, but not always with pristine results, the machine descends and returns in a mere 33 minutes.
It travels 60 feet a minute while shooting water from a spray nozzle, brushing, and then vacuuming the windows. Ten bays may be cleaned in a day, and the water, which is recycled, is changed after 5 bays. The entire machine, including the washer head and cable reels, weighs about 3,000 pounds.
Because of the way the buildings are constructed, the automatic window washer cannot be used on either the uppermost or the lowest floors.
The windows of the 107th floor, the restaurant in Tower 1 and the observation deck in Tower 2, are washed four times a year by two brave souls who hang from scaffolding and wash with the usual brushes and squeegees. They also wash floors 1 through 6 by hand.
They omit floors 7 and 8, 108 and 109, and several others that contain mechanical equipment rooms with vents for blowing air out of the buildings to aid air circulation, these floors have no windows.
Related Posts
-
Where Did the Word Window Come From and What Did “Window” Mean Originally?
Early Norse homes were simply designed and often included a stable area for livestock under the same roof as the humans. In the winter, because the tightly shut doors trapped stale air and…
-
Why Are the Windows of Old Wooden Ships Square and Why Are the Windows of Modern Steel Hulled Ships Round?
Many old pictures and prints of wooden ships, show portholes, usually gun ports, that are square or rectangular, but ports are round in steel-hulled ships. When ships were made of wood, the architectural…
-
Why Do Airplanes Have Such Small Windows and Why Are the Tiny Windows On Airliners Positioned So Low?
As with many things concerning the design of an aircraft, the final arrangement of various parts is based upon a series of compromises. An aircraft designer's life would be so much easier if…
-
What is meant by the term geographic center and what is the geographic center of the United States?
What the United States Census Bureau calls the geographic center of area is the point on which the surface of a geographical entity would balance if the surface were a plane of uniform…
-
How did Wall Street Get its Name and How Did the Center of Trade and Commerce Originate?
In September of 1653, the settlers in what is now New York City felt threatened by the local Natives and by the possibility of an invasion by Oliver Cromwell's army. For protection, they…
-
What was the fur trade about and When did the fur trade in North America start?
Beginning in the late 1500s, traders from France, England, and the Netherlands flocked to North America to trade with Indians for animal furs. Europeans wanted furs to make warm winter clothing. The demand…
