London’s iconic Big Ben clock tower will fall silent next year for some months, as work begins on a three-year long restoration project. The city landmark will be repaired and refurbished at an estimated cost of 29 million pounds (about $42.5 million).

After 157 years of the clock's continuous service, the British parliament has taken the step to carry out essential repair work. The parliament announced that urgent works need to be carried out on the country's most famous clock and the tower that houses it, the Elizabeth Tower. The tower was renamed in 2012 in honor of Queen Elizabeth II’s Diamond Jubilee celebrations.

It has been over 31 years since extensive works last took place. Problems have been identified with the clock hands, its mechanism and the pendulum, which have led the clock to show inaccurate time or to stop altogether. The refurbishments will ensure the clock continues to keep time as well as enhance the life of the structure. 

The clock will be stopped for several months while maintenance work is carried out. And there will be no chiming or striking during this period, except to mark important events like the New Year. The hands, bearings, gears and drive mechanism of the clock will go under repair for the shortest possible time, and parliament has assured that one face of the clock will keep showing the correct time. The clock tower also needs to be brought under fire prevention guidance.

As for the tower itself, cracks in the masonry, leaks, erosion, and severe rusting of metalwork have been identified as areas of concern.

As part of the repair work, a lift will be installed within the shaft of the tower to provide a better means of emergency evacuation. But, it will not be part of the visitor experience, which involves climbing 334 steps.

Big Ben was designed by architects Charles Barry and Augustus Wellby Pugin and completed in 1856.

Correction: A previous version of the story noted that London’s Big Ben clock tower will fall silent next year for a period of three years. But the clock mechanism will need to be stopped only for a few months to carry out maintenance work. Striking and tolling will be maintained for important events. The story has since been corrected to reflect that.