On April 30, 1997, at exactly 12:11 pm, London's iconic Big Ben clock stops ticking. For 54 minutes, the most famous clock in the world failed to keep time. Completed in 1859, Big Ben has a long history of technical issues.

While "Big Ben" is technically the name of the Great Bell, the clock tower (Elizabeth Tower) has seen several major stops, the most significant being the four-year conservation project that began on August 21, 2017. During this time, the bells were silenced for the safety of workers, except for special occasions like New Year's Eve and Remembrance Sunday. The clock formally resumed its full regular service in November 2022. Historically, the clock has also stopped due to mechanical failures, such as in 1976 when a metal fatigue fracture caused the chiming mechanism to explode, stopping the clock for nine months. It also famously stopped in May 2005 for 90 minutes due to record-breaking heat in London, and again in 2023 for a brief period of technical adjustment following the massive renovation. Today, in 2026, the clock is fully operational, maintaining its reputation as one of the most accurate mechanical clocks in the world after its $100 million restoration, which included cleaning the 312 pieces of pot opal glass in each of its four faces.