It has been the marker by which Londoners set their watches by for 156 years, but Big Ben has been chiming incorrectly, interrupting live radio broadcasts and confounding the clocksmiths.
The bongs started to go wrong by up to six seconds at the weekend after becoming “temperamental” in old age, technicians admitted this morning.
As a result, the bell has been interrupting BBC Radio 4 broadcasts that use the chimes live on air.
It started going off kilter about two weeks ago and the three dedicated parliamentary clocksmiths, who use the talking clock to check Big Ben’s accuracy, adjusted the pendulum to try to correct the problem, making it run slow.
Ian Westworth, one of the clocksmiths, told Radio 4’s PM programme: “The error started building up and went slightly unnoticed over a weekend. You can’t just wind the hands forward. You have to make a very gradual change by adding coins to speed up the clock or taking weight off to slow it back down again.
Advertisement
“We don’t know why it happened. You’re talking about a 156-year-old clock, it does have a little fit every now and then. It’s a little temperamental.
“Imagine running your car for 24 hours a day, 365 days a year for the last 156 years.”
An initial correction made the clock run slow, leading Mr Wentworth and his team back to the talking clock.
Mr Westworth said: “We have been up there most days trying to get it right. Traditionally we have to go up three times a week to wind the clock.
“We phone up the speaking clock and at five minutes to the hour start a stopwatch, go up to the belfry, stand by the bell and hammer. As it strikes the bell we’ll stop the stopwatch. We can tell if it’s going slightly fast or slow.”
Advertisement
It is not the first problem Big Ben has suffered, but it has been remarkably resilient.
The Palace of Westminster was destroyed by fire in 1834 and the new Houses of Parliament were to have a tower and a clock.
The first bell they tried to make cracked irreparably and was recast in 1858. The first chime from Big Ben was on May 31, 1859, but it cracked in September of that year. A lighter hammer was introduced and the bell rotated to present an undamaged section. That is the sound we hear today.
The bell and tower survived a bomb blast during the Second World War that destroyed the Commons chamber.
The clock tower was renamed Elizabeth Tower to mark the Queen’s diamond jubilee and the bell remains, as ever, Big Ben.