London: Tower Bridge glass walkway opens

Would it be possible, one might wonder, for pedestrians down below to look up and see more than they had bargained for?

Apparently not. Staff at Tower Bridge moved to assure the public there was no risk of such embarrassment since the glass from which the floor is made is "too thick" to see through from beneath.

The view from below is further restricted by the fact that the walkway is not directly above the pavement but slightly off at an angle.

A spokesman said: "This question was discussed, and no it won't be possible [to see up women's skirts].

"Pedestrians can look up but the walkway is not directly above them, it's a little bit off-centre."

However, those behind the project did have to consider the risk, they admitted.

"This was a consideration at the outset of the design process," the spokesman said.

"The layers within the glass, combined with careful control of the lighting system within the walkway between day and night time, address this potential issue."

There are also plans in the pipeline for additional lighting to be installed underneath the walkway, which will shine light directly on to the exterior panel surface.

This will "further enhance the effectiveness of the above solution, and allow visitors to see through the glass from above while creating a 'mirror' effect when looking up from road level," a Tower Bridge Exhibition statement explained.

Fascinating facts

After eight years in the making, Tower Bridge was officially opened in 1894 by the Prince and Princess of Wales, the future King Edward VII and Queen Alexandra.

More than 50 designs were submitted for the bridge. The judging process was highly controversial; a design by Sir Horace Jones - who sat on the panel - was eventually approved. Jones died soon after construction began and George D. Stevenson took over, giving the Jones's original brick facade a more ornate Gothic style.

The bridge originally linked Iron Gate, on the north bank, with Horselydown Lane, on the south. Those roads are now known as Tower Bridge Approach and Tower Bridge Road, respectively.

Prior to the opening of the bridge, those wishing to cross the river here would have used the Tower Subway - a 410-metre tunnel. Once used by one million people a year (each paid half a penny to do so), it closed to pedestrians in 1898 and is now used for water mains.

The bridge initially faced criticism from architectural experts. H.H. Statham wrote in 1916 that it represented "the vice of tawdriness and pretentiousness". F Brangwyn and W.S. Sparrow's Book of Bridges (1920) labels the structure "absurd".

A popular myth states that Robert P. McCulloch, the US entrepreneur, purchased the old London Bridge (which was later rebuilt at Lake Havasu City, Arizona) in the belief that it was the more famous Tower Bridge.

The high-level, open-air walkways between the two towers were once a haunt for prostitutes and pickpockets, and closed in 1910. They reopened in 1982 with an admission fee.

In 1952, the bridge began to open while a double-decker bus was still on it. The number 78, which was being driven by Albert Gunton, had to accelerate and jumped a small, three-foot gap. He was awarded £10 ($A18) for his bravery.

The Hawker Hunter Tower Bridge incident in 1968 saw Flight Lieutenant Alan Pollock, angry at the lack of aerial displays planned to mark the 50th anniversary of the RAF, take matters into his own hands. He took his Hawker Hunter jet on an unauthorised low-level flight, circling the Houses of Parliament three times, dipping his wings over the RAF Memorial and flying under the top span of Tower Bridge. "It was easy enough to fly over it, but the idea of flying through the spans suddenly struck me," he said. "I had just ten seconds to grapple with the seductive proposition which few ground attack pilots of any nationality could have resisted."

Ships always have right of way. That fact was made clear in 1997 when Bill Clinton's presidential motorcade was split crossing Tower Bridge to allow the Thames sailing barge Gladys to pass as scheduled. "We tried to contact the American Embassy, but they wouldn't answer the phone," said a Tower Bridge spokesman.

A replica of Tower Bridge can be found in the Chinese city of Suzhou. It has a cafe inside offering "English-style coffee".

In numbers

Five minutes

How long it takes to raise each half (bascule) of the bridge's central stretch to allow large ships to pass.

8 years

How long it took to build (1886-1894).

432

Number of construction workers it took to build the bridge

31,000,000

The number of bricks used, along with 2 million rivets and 22,000 litres of paint.

1,184,000

Total cost of construction in pounds at the time it was built (which amounts to about £118m in 2014)

18 tons

Weight limit of vehicles using the bridge

32 kilometres

Speed limit for vehicles using the bridge

86 degrees

Maximum angle each bascule can be raised.

43.5 metres

Height (above water) of the pedestrian walkways at high tide

65 metres

Height of each of tower

244 metres

Total length of the bridge in feet

1,000

Approximate number of times the bascules are raised each year. 24 hours' notice is required, but there is no charge for vessels.

40,000

Average number of people, including motorists, cyclists and pedestrians, crossing the bridge every day

The Telegraph, London