Civil engineers say the clock tower is no longer straight and the tilt is getting worse every year
Move over Pisa -- London has got its very own leaning tower. London's Big Ben is leaning so much that the tilt can now be seen with the naked eye, it emerged today.
Civil engineers have discovered that the clock tower at the Palace of Westminster is no longer ramrod straight and the problem is getting worse every year.
Lean times: Big Ben tower, which was finished in 1858, has been affected by decades of underground workings. file pic/getty images
The top of the tower is now almost one-and-a-half feet off the perpendicular and if left uncorrected it would eventually fall.
But before MPs start running scared, at the current rate of movement it would be 4,000 years before it would match the angle of the Leaning Tower of Pisa and even longer to actually topple.
Surveyors believe Big Ben is sinking into the ground because of decades of underground building work since it was built in 1853. If Big Ben were to fall it would crash into MPs' offices over the road in Portcullis House.
Currently, the clock tower is sinking more quickly on the north side of the 315ft-tall building.
Engineers cannot explain why the tower's clock face moved up to an eighth of an inch away from the vertical between November 2002 and August 2003.
Since 2003, monitoring instruments show the tilt has increased 0.04 inches a year, compared to the long-term average rate of just 0.025 inches a year. The report revealed that the tower was now leaning towards the north-west at an angle of 0.26 degrees, meaning the top of the tower is 1 foot 5 inches from vertical.
The Leaning Tower of Pisa leans by around four degrees.
John Burland, senior research investigator from Imperial College London said, "The tilt is now just about visible. I have heard tourists there taking photographs saying 'I don't think it is quite vertical' - and they are quite right.
If it started greater acceleration, we would have to look at doing something but I don't think we need to do anything for a few years yet."
315 The height (in feet) of the Clock Tower, popularly known as the Big Ben
Did you know? The Big Ben was designed by Charles Barry and became operational on September 7, 1859. It is also the biggest four-faced chiming clock in the world. The weight of the tower is a hefty thirteen and a half tonnes.