LONDON, England (Reuters) -- The "bongs" of London's Big Ben stopped on Saturday for up to six weeks as the clock's chimes were shut down for maintenance work.



The London landmark is undergoing maintenance work ahead of its 150th anniversary in 2009.



At 8 a.m. (0700 GMT) the bells of the landmark Westminster clock tower were silenced for the final phase of a program of work ahead of the clock's 150th anniversary in 2009.



An hour later, Londoners and tourists saw the unusual spectacle of workers abseiling down the south clock face to clean and repair it. Both hands of the clock were turned to 12.



An electric system will keep the clock moving while work takes place on the mechanism.



The stoppage will be the longest suspension of Big Ben since 1990. There were previous stoppages of both the hour and quarter bells in 1956 and 1934.



The 96 meter (315 ft) clock tower of Britain's parliament is popularly known as Big Ben, although the name actually refers to the 13.5 tonne Great Bell inside. E-mail to a friend
What stopped on Saturday? What have been shut down for maintenance work? When is the anniversary of Big Ben? What is meant by bong? How long is the maintenance for? How long are the chimes off? What will be the longest suspension of Big Ben since 1990?
The "bongs" of London's Big Ben The "bongs" of London's Big Ben 2009. clock's chimes up to six weeks up to six weeks six weeks
question: What stopped on Saturday?, answer: The "bongs" of London's Big Ben | question: What have been shut down for maintenance work?, answer: The "bongs" of London's Big Ben | question: When is the anniversary of Big Ben?, answer: 2009. | question: What is meant by bong?, answer: clock's chimes | question: How long is the maintenance for?, answer: up to six weeks | question: How long are the chimes off?, answer: up to six weeks | question: What will be the longest suspension of Big Ben since 1990?, answer: six weeks