Tower Bridge (built 1886–1894)
is a combined bascule and suspension bridge in London which crosses the River
Thames. It is close to the Tower of London, from which it takes its name, and
has become an iconic symbol of London. It took 8 years, 5 major contractors and
the relentless labour of 432 construction workers to build Tower Bridge.
The bridge consists of two
towers tied together at the upper level by means of two horizontal walkways,
designed to withstand the horizontal forces exerted by the suspended sections
of the bridge on the landward sides of the towers. The vertical component of
the forces in the suspended sections and the vertical reactions of the two
walkways are carried by the two robust towers. The bascule pivots and operating
machinery are housed in the base of each tower
("bascule" comes from the French for "see-saw"). Today, the bascules are still operated by
hydraulic power, but since 1976 they have been driven by oil and electricity
rather than steam.
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| In this vintage postcard, a steamship with a large funnel can be seen in the Thames. |
The bascules are raised
around 1000 times a year. River traffic is now much reduced, but it still takes
priority over road traffic. Today, 24 hours' notice is required before opening
the bridge. There is no charge for vessels.
In 1910, the high-level
walkways, which were designed so that the public could still cross the bridge
when it was raised, were closed down due to lack of use. In 1982, as part of
the new Tower Bridge Exhibition, visitors to the bridge could once again enter
the walkways, now fully covered, and experience the amazing panoramic views.
One final note: Tower Bridge is not to be confused with
London Bridge which is a different bridge.
The second postcard came from Ellie P. (17 September 2014) Swap-bot.
The third postcard came from Requel (5 May 2015) Postcrossing.
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