Bid to straighten the story of Leaning tower of Big Ben

LONDON // Big Ben, one of London's most famous landmarks, is developing a tilt, surveyors have found.

A committee of MPs have embarked on the tricky question of what, if anything, to do about the leaning Parliamentary Clock Tower, as it is properly known (Big Ben is actually the main bell that rings out the hour), and whether or not its condition is damaging the fabric of the Houses of Parliament, built on the banks of the Thames more than 150 years ago.

The problem is that nobody is quite sure if the lean, which is nowhere near the four degree tilt on the Leaning Tower of Pisa, is getting dramatically worse or if it has always been there.

A survey undertaken in 2009 but not published until a few months ago, suggested "an increased rate of movement" in the 96 metre-tall tower, which was built in 1858. It said the tower was leaning at an angle of 0.26 degrees towards the north-west.

But John Burland, emeritus professor in construction research at Imperial College London, said on Monday that the lean was nothing to worry about and that the tower had probably not been built exactly vertical in the first place.

Prof Burland said the tilt had been obvious when he worked on the design of an underground car at the Houses of Parliament more than 30 years ago.

The construction of the car park and a new tunnel for Jubilee Line underground trains, built in the mid-90s, have both been blamed for enhancing the list.

MPs on the Commons Commission are not only worried about the clock tower, however, but cracking in the neo-Gothic fabric of the Houses of Parliament.

There were even suggestions in the British press on Monday that the building might have to be abandoned while repair work was carried out.

Prof Burland, however, dismissed the stories. "There's no such thing as an old building that isn't cracked," he said. "In fact, they're beneficial because the building moves thermally more than is caused by the Jubilee Line. And the movements are concentrated around the cracks and, if they weren't, there'd be cracking elsewhere.

"So these have been there for years and they're certainly not caused by the Jubilee Line or the car park."

It has been estimated that the leaning tower of Big Ben, which is just about visible to the naked eye, will take about 4,000 years at the current rate to reach the same, jaunty angle as its more celebrated leaning cousin in Pisa.