Mintz

Johanna Mintz
 * 1) What is the name of the bridge? I researched the Tower Bridge.[[image:http://www.photoatlas.com/photo/uk_london_tower_bridge.jpg width="397" height="293"]]
 * 2) When and where was the bridge built? Construction started on the Tower Bridge in 1886 and the bridge was officially opened in London on June 30, 1894.
 * 3) What is the purpose of this bridge? What does it span and what does it connect? The purpose of the bridge was to provide transportation for motor vehicles, cyclists, and pedestrians. The bridge spans 61 meters, and it connects the Borough, to the heart of the City of London.
 * 4) Why was this bridge needed? The Tower Bridge was need because there was increased commercial development in the second half of the 19th century and it led to requirement for a new river. A traditional fixed bridge could not be built because facilities in the Pool of London, between the London Bridge and the Tower of London, access would be cut off.
 * 5) What type of bridge is it (arch, suspension, cable, beam, etc.)? The Tower Bridge is a Bascule Bridge and a suspension Bridge.
 * 6) How much did it cost? It cost 1,840,000 pounds and as of 2010 it has cost 100 million pounds.
 * 7) What materials were used to build this bridge? The two massive piers on the Tower Bridge contain over 70,000 tons of concrete, steel was used as framework for towers and walkways, and then it was dressed in cornish granite and Portland stone, which helped protect underlying steelwork and give the bridge a pleasing appearance.
 * 8) What were some of the special challenges that the bridge engineers faced? How did they overcome these challenges? The engineers working on this bridge faced the challenge of building a bridge over a busy river with low, banks so that shipping would not be obstructed. They overcame this challenge by building an opening type of bridge, a bascule bridge.
 * 9) How long did it take to build this bridge? It took 8 years to build the Tower Bridge.
 * 10) What are the measurements of this bridge? The total length of the bridge is 244 meters, and the clearance is 8.6 meters when it is closed, and 42.5 meters when it is open. It's longest span is 61 meters, and the 2 towers are both 65 meters. The bascules, weighing over 1,000 each, are counter balanced to minimize the force required, which allows the bridge to raise in 5 minutes.
 * 11) Did you find any fun or interesting facts or stories about this bridge? The Tower Bridge is sometimes mistakenly referred to as the London Bridge, which is actually the next bridge upstream. Currently the bridge is undergoing a renovation project that should be completed in 2012. The bridge used to open 50 times a day, but nowadays it only raises about 1,000 times a year!

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