Long Now Clock engineer Paolo Salvagione sent in this excellent write up by fellow horological geek Alex Doak of Watchismo of his trip to see Big Ben ring in its 150th year. It includes a link to animated “how Big Ben works” that is one of the best clock descriptions I have seen. Most interesting to me of course were the descriptions of the stoppages and challenges involved:
Stoppages are rare, but the most notable are:
2007: the longest suspension of the hour strike (Big Ben) since 1990. Big Ben’s famous ‘bongs’ were silent for seven weeks in 2007, allowing essential maintenance work on the clock mechanism to take place. From 11 August to 1 October, an electric system kept the clock moving, but Big Ben, the name for the Great Bell, and the quarter bells were quiet. This was the final phase of a programme of planned works to prepare for the Great Clock’s 150th anniversary in 2009.
October 2005: The clock mechanism was also suspended for two days in to allow inspection of the brake shaft.
Over the years, the clock has been stopped accidentally on several occasions – by weather, workmen, breakages or birds. The most serious breakdown occurred during the night of 10 August 1976 when part of the chiming mechanism disintegrated through metal fatigue, causing the mechanism to literally explode under its own immense forces, dropping its weights to the base of the Tower with a noise that the policeman on duty initially reported as being an IRA bomb. The Great Clock was shut down for a total of 26 days over nine months – the longest break in operations since it was built – until it was fully repaired.
