
The following is a summary of the main facts about the clock, tower and bells.
The Clocktower
 The total height of the tower is 316 feet
 The height of the belfry is about 200 feet
 There are 290 steps to the clockroom and 340 to the belfry
The Bells
 The quarter chiming bells are in the key of F
 The hour bell (Big Ben) is note E and weighs 13.5 tons and has a maximum diameter of 9 feet
 The hammer of the hour bell weighs 4 cwt.
 The four quarter bells weigh (in order of size) 1 ton, 1.25 tons, 1.6 tons and 3.5 tons
The Dials and Hands
 The diameter of each of the four dials is 23 feet
 Each dial contains 312 panes of glass (and we are happy to dispel the myth that there are 365, one for each day of the year, yes, we've counted them!)
 28 bulbs are used to light each dial from behind
 The hour hands are 9 feet long and weigh 0.8 cwt.
 The minute hands are 14 feet long and weigh 2.5 cwt.
 The Roman numerals are 2 feet high
The Clock Movement
 Three train flatbed movement with Grimthorpe's double threelegged gravity escapement and twosecond pendulum
 The frame of the movement is about 16 feet long and the entire machine weighs 5 tons
 The driving weights weigh 2 cwt. (going), 1 ton (striking) and 1.25 tons (chiming)
 The chiming and striking trains have been wound by motor since 1912 but the previous hand winding took two men 5 hours per train
 The going train is still wound by hand which takes less than 30 minutes
 The overall length of the pendulum is about 14 feet and it weighs 2.5 cwt.
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