The mechanism of the Great Clock was designed by Edmund Beckett Denison and George Airy, the Astronomer Royal. Construction was entrusted to the London firm of E J Dent, who completed it in 1854. Pugin’s tower took another five years, during which time Denison was able to experiment and instead of using the deadbeat escapement and remontoire, as originally planned, he substituted the more accurate three-legged gravity escapement.
The quarter bells were cast by John Warner & Sons in London. They also cast the original Big Ben in their Stockton-on-Tees foundry, but it cracked beyond repair during testing and it was melted down and a replacement cast at the Whitechapel Foundry. At over thirteen tons it was the largest bell ever cast in Britain at that time and became an instant celebrity. Transporting the bell the few miles from the foundry to the Houses of Parliament was a major event. Traffic stopped as the bell, mounted on a trolley drawn by sixteen brightly beribboned horses, made its way through the streets, which had been decorated for the occasion, cheered along by enthusiastic crowds.
It first chimed in 1859 but in a matter of months it had also cracked due to the hammer being too heavy. It was out of service for three years, but eventually having been given an eighth of a turn and a lighter hammer, rang out with the distinctive tone we still hear today.
Extract from an article in the Winter 2017 edition of “Mechanical Music World”