Big Ben Turns 150 Years Old

On May 31st, 2009, the celebrated British historical landmark known as Big Ben officially celebrated its sesquicentennial.

The name “Big Ben” actually refers to the 13.5-ton copper and tin bell (housed in St. Stephen’s Clock Tower atop Westminster Palace), not to

Big Ben
Big Ben in London

the clock mechanism itself. The “bong” of the massive bell measures 118 decibels – as loud as a modern jet airliner on takeoff.

The massive clock was designed by Sir Charles Barry with the help of Augustus Pugin, after the Palace of Westminster was destroyed by fire in 1834. The installation of the clock and bell mechanism was finished in 1859. At 320 feet, the clock tower is the world’s tallest.

The booming E flat tone of the bell was silent during World War I for fear of attracting Zeppelins, but during the Blitz of World War II the clock was never silent.

A sudden mechanical failure at 4 a.m. on August 5, 1976, caused near panic in London; the clock started striking and couldn’t be silenced until serviced by the Palace of Westminster’s three full-time clock mechanics.

The flatbed clock mechanism – a revolutionary technology 150 years ago – continues to tick with remarkable accuracy, its 15-foot pendulum swings at two-second intervals, with minor adjustments for expansion or contraction using pre-decimal pennies: 1d (penny) speeds the clock up by 2/5th of a second over 24 hours.

Big Ben Facts

* The clock started keeping time on May 31 1859; the bells began ringing on July 11 of the same year.

* Each face is lit by 27 low-energy, radio-controlled bulbs.

* The “Westminster” chimes were copied from Great St. Mary’s in Cambridge.

* Tunneling for a line of the London Underground left the tower leaning 220mm (8.66 in) to the north-west.

* The minute hand is 14 feet long; the hour hand is 9 feet long.

* The north and east faces of the clock have heaters to prevent the hands from freezing.

bigben.parliament.uk