It has chimed through freezing winters, fierce storms and World War II bombing raids. But old age will silence Big Ben's bongs - at least temporarily.
The famed bell that sounds the hour at Britain's Houses of Parliament is to fall silent during scheduled repairs for only the fourth time in a century and a half.
The bongs will strike for the last time at 8 a.m. Saturday before four to six weeks of maintenance work on the clock.
Mike McCann, Parliament's Keeper of the Great Clock, said Thursday that Big Ben has been silenced for repairs only three times before - in 1934, 1956 and 1990 - although it has been briefly halted a few times by weather and accident.
This is the first time since 1956 that both the sonorous hourly bongs and the chimes that mark each quarter-hour will be silent, robbing London of one of its most distinctive sounds.
"Depending on the wind and traffic, sometimes you can hear it a mile and a half away," McCann said.
The famous bong echoed throughout the city without fail through World War II bombing raids. Records show the clock slowed during heavy snowfalls in 1962, sounding 10 minutes late on New Year's Eve.
House of Commons officials said a team of specialist "industrial rope-access technicians" would rappel down the tower's south clock face Saturday. The team will spend a day cleaning and repairing the clock's four faces.
A backup electric system will keep the clock running as technicians replace the bearings on mechanisms that operate the hour bell and drive the clock.
McCann said he believed this was the first such replacement since the clock was installed in 1859.
The maintenance work is the final phase of a program of renovation to prepare for the clock's 150th anniversary in 2009.