Big Ben’s famous chimes will be temporarily silenced after 157 years of almost uninterrupted service as the famous London Clock tower undergoes £29m (US$42.2m, €37.4m) worth of urgent repairs.

The work, which is to prevent Big Ben’s mechanisms from failing, will take three years to complete. In that time, the Elizabeth tower which houses the famous clock, will undergo essential maintenance and repairs.

The clocks will not be stopped for the entire three-year period, but will fall silent for several months. Striking and tolling will also be maintained for important events.

As part of the works, the refit could see the clock faces of the tower stripped of the black and gold colouring applied in the 1980s to return them to their original appearance, thought to be green and gold.

Work will be carried out to fix cracks in the masonry, cast-iron roof and belfry, as well as the frame which holds the bells including the famous 13.5 tonne Big Ben. Additionally the tower will be brought up to modern health and safety standards and a lift will be installed in one of the ventilation shafts to improve access for the disabled and emergency services.

The clock, designed by Edmund Beckett Denison, first started keeping time on 31 May 1859. The tower was completed in 1856 after 13 years of development and was designed by architects Charles Barry and Augustus Welby Pugin.

As an attraction, Elizabeth Tower is visited by 12,000 people a year, also drawing hundreds of thousands of international tourists visiting the London landmark as they tour the city.

Work is scheduled to begin in early 2017. The works will be let through a contract tendered via the EU procurement OJEU process. Clock mechanism repairs will be carried out by our internal team where possible.