|
It is already leaning less and will soon be squeaky clean: the Tower of
Pisa has a new lease on life. The current cleaning will complete a seven-year
restoration project.
Rainwater stains, car exhaust fumes and calcium encrustations have damaged
the tower's marble and mortar. The cleaning, which began late last month, will
be completed in June at a cost of $A800,000.
The tower was closed to visitors for 10 years until last year because of its
dangerous tilt, but while the cleaning is going on it can be visited by groups
of 30.
In 1995 a Polish-born engineer, Michele Jamiolkowski, won an international
competition with his scheme to prevent the tower toppling.
The eight-storey, 54.5-metre high, 14,500 tonne tower was built on a site
soggy on one side because of an underground stream. It was begun in 1174, and by
the time the final storey was added in 1350 it already had about half its 1995
tilt of 4.5m from the perpendicular.
The Jamiolkowski solution was to extract 50,000 cubic metres of soil from
the higher northern side, attach there 800 tonnes of lead counterweights, and
apply steel trusses, anchored in the square, to the brittle tower to prevent it
snapping.
Dr Jamiolkowski says his $A46million restoration will save the tower for 300
years, but admits it will take 10 years to really test the outcome.
The cleaning firm has previously refurbished Roman church facades. However,
pollution is already discolouring them again, and the same may happen to the
tower.
Despite the restoration, the tower still has a big tilt, having been
straightened by just 43.5 centimetres at the top.
|
Print Entire Page
