Friday, December 25

Tower Bridge


We cross the majestic river while my photo facing east towards Tower Bridge; to the left, the peaks of Canary Wharf on the Isle of Dogs three miles upriver.  London is a good walk, too - each neighborhood's history remembered in brick, stone or metal.  Our route begins at the Tate Modern, then Millenium Bridge to the Wren Cathedral. From there, Cheapside (where the Great Fire began) and the Bank of England followed by Lloyds of London and the Swiss Re Gherkin, the Sir Francis Drake and finally The Globe.  All this inside two hours. It is a perfect day for a walk - cold and clear with plenty of moisture in the air. No sane Englishman to be seen Christmas Day though we bump into Italians and Japanese, who photograph pigeons (I have never understood this).

In the second half of the 19th century, the East End's development demanded a new river crossing downstream from London Bridge (where I take this picture). A traditional fixed bridge could not be built because it would cut off access to the port facilities in the Pool of London, between London Bridge and the Tower of London.  A Special Bridge or Subway Committee was formed in 1876 to oversee a solution - they opened the design to a public competition similar to, say, The Freedom Towers in NY. 50 plans submitted, including one from architectural hero Sir Jospeph Bazalgette who built, like, everything of great importance during the Victorian era.  All sorts of controversy ensued (also like NY), and it was not until 1884 that a design submitted by Horace Jones, the City Architect (who was also one of the judges), was approved.

So finally construction started in 1886.  Eight years, five contractors, 432 construction workers and - voila! - the bridge done: two massive piers of 70,000 tons of concrete sunk into the riverbed supporting 11,000 tons of steel which, in turn, provide the framework for the towers and walkway. This clad in Cornish granite and Portland stone to protect the underlying steelwork and to give the bridge a rather pleasing appearance. Total construction cost: £1,184,000 (sources: "Cross River Traffic" by Robert Chris, 2005; "Tower Bridge" Archive- The Quarterly Journal for British Industrial and Transport History; The Times)

And more: the bridge is 800 feet whose towers 213 feet high, built on piers. The central span of 200 feet between the towers split into two equal bascules or leaves, which can be raised to an angle of 83 degrees to allow river passings including Michael Jackson. The bascules, weighing over 1,000 tons each,  counterbalanced to minimize the force required and allow raising in five minutes. The two side-spans are suspension bridges, each 270 feet long, with the suspension rods anchored both at the abutments and through rods contained within the bridge's upper walkways. The pedestrian walkways are 143 feet above the river at high tide (Source: "Tower Bridge" Archive- The Quarterly Journal for British Industrial and Transport History).

Katie: "That Habitrail is complex."