Dome

The upper south twin tower, west flank; The Tower Bridge is a bascule bridge and solved the problem of allowing river traffic to pass under the bridge and relieved the traffic on London Bridge. The bridge lifted 6,000 times in its first year. Bascule bridges have sections called "leaves" that rotate upward and away from the centerline of the river, providing clear passage for river traffic. It was designed by Sir Horace Jones and engineered by Sir John Wolfe-Barry, and construction began in 1886. The project was completed in 1894. The towers, covered in ornate Victorian masonry, stand 206 ft., 63 m. tall and are constructed of a steel frame -- stonework has no structural function. The structure has a main span of 200 ft., 61 m., with a bascule roadway and two steel walkways which are 140 ft., 43 m. high. "Jones's chief contribution to London was Tower Bridge (1886-1894), which he designed in collaboration with the engineer John Wolfe Barry (1836-1918). Although the Gothic detailing executed after Jones's death is arid, the overall concept and silhouette made it a world-famous landmark." Source: Grove Art Online; http://www.groveart.com/ (accessed 1/25/2008)