Lord Be My Guide – Big Ben – Additional Statistics
The face of the Great Clock of Westminster – the hour hand is 9 ft [2.7 metres] and the minute hand is 14 ft [4.3 metres] long. The clock faces are set in an iron frame 23 ft [7 metres] in diameter, supporting 312 pieces of glass, rather like a stained glass window. Some of the glass pieces may be removed for inspection of the hands. The surround of the dials is gilded. At the base of each clock face in gilt letters is the Latin inscription: DOMINE SALVAM FAC REGINAM NOSTRAM VICTORIAM PRIMAM, which means, O Lord, keep safe our Queen Victoria the First.
The pendulum of the clock is installed within an enclosed windproof box sunk beneath the clock room. It is 3.9 metres long, weighs 300 kg and beats every 2 seconds. The clockwork mechanism in a room below weighs 5 tons. On top of the pendulum, as a means of fine tuning, is a stack of old penny coins; these are to adjust the time of the clock. Adding or subtracting coins has the effect of minutely altering the position of the pendulum’s centre of mass, the effective length of the pendulum rod and hence the rate at which the pendulum swings. Adding or removing a single penny will change the clock’s speed by 0.4 of a second per day.
The Great Bell (Big Ben) first chimed in July 1859. It had been pulled 200 ft up to the Clock Tower’s belfry, a feat that took 18 hours. It is 2.2 metres tall and 2.9 metres wide. However, in September 1859 it cracked under the hammer, a mere two months after it officially went in to service. According to the bell foundry’s manager the the clock designer had used a hammer more than twice the maximum weight specified. For three years Big Ben was taken out of commission and the hours were struck on the lowest of the quarter bells until it was reinstalled. To make the repair, a square piece of metal was chipped out from the rim around the crack, and the bell given an eighth of a turn so the new hammer struck in a different place. Big Ben has chimed with an odd twang ever since and is still in use today complete with the crack.
Despite Big Ben being one of the world’s most famous tourist attractions, the interior of the Clock Tower is not open to the general public due to security concerns, although from time to time the press and other VIPs are granted access. However, the tower has no lift [elevator], so those escorted must climb the 334 limestone stairs to the top. Because of changes in ground conditions since its construction (notably tunnelling for the Jubilee Line extension – one of the many London Underground lines), the tower leans slightly to the north-west, by roughly 8¾ inches [220 millimetres] at the clock face, giving an inclination of approximately 1/250. Due to thermal effects it oscillates annually by a few millimetres east and west.
On the 10th May 1941, a German bombing raid damaged two of the clock faces and sections of the tower’s stepped roof, and destroyed the House of Commons chamber in the Palace of Westminster. The replacement section was designed as a five-floor block. Two floors are occupied by the current camber which was used for the first time on the 26th October 1950. Despite the heavy bombing Big Ben ran accurately and chimed throughout the London Blitz . History repeated itself: in 1915/16 for two years during World War I, the bells were silenced and the clock face darkened at night to prevent attack by German Zeppelins. On the 1st September 1939, although the bells continued to chime, the clock faces were again darkened at night through the years of World War II to prevent guiding the bomber pilots of the German Luftwaffe in the Blitz.
Modern historical facts: On New Years Eve 1962 the clock slowed down due to heavy snow and ice on the long hands, causing the pendulum to detach from the clockwork, as it is designed to do in such circumstances to avoid serious damage elsewhere in the mechanism – the pendulum continued to swing freely. It therefore chimed in the New Year of 1963 ten minutes late! On the 5th August 1976 Big Ben suffered its first and only breakdown. The speed regulator of the chiming mechanism finally broke after 100+ years of metal fatigue, with the result that the fully-wound 4 ton weights dumped their entire potential energy into the chiming mechanism in one go. It caused a great deal of damage; the Great Clock was shut down for a total of 26 days over nine months – it was reactivated on the 9th May 1977; this was its longest break in operation since it was built.
On the 27th May 2005 the clock stopped at 10.07 pm local time, possibly doe to hot weather (temperatures in London had reached an unseasonal 90ºF [31.8ºC]. It restarted itself, but stopped again at 10.20 pm local time and remained still for about 90 minutes before restarting. Later that same year, on the 29th October 2005 the mechanism was stopped for about 33 hours so that the clock and its chimes could be worked on. It was the lengthiest maintenance shutdown in 22 years. At 7.00 am on the 5th June 2006 the clock tower’s “Quarter Bells” were taken out of commission for four weeks as a bearing holding one of the quarter bells was damaged from years of wear and needed to be removed for repairs. On the 11th August 2007 a 6-week stoppage for maintenance began. Bearings in the clock’s drive train and the “Great Bell” striker was replaced for the first time since installation. During the maintenance works, the clock was not driven by the original mechanism, but by an electric motor – so Big Ben continued to record the time, albeit silently!
The pendulum of the clock is installed within an enclosed windproof box sunk beneath the clock room. It is 3.9 metres long, weighs 300 kg and beats every 2 seconds. The clockwork mechanism in a room below weighs 5 tons. On top of the pendulum, as a means of fine tuning, is a stack of old penny coins; these are to adjust the time of the clock. Adding or subtracting coins has the effect of minutely altering the position of the pendulum’s centre of mass, the effective length of the pendulum rod and hence the rate at which the pendulum swings. Adding or removing a single penny will change the clock’s speed by 0.4 of a second per day.
The Great Bell (Big Ben) first chimed in July 1859. It had been pulled 200 ft up to the Clock Tower’s belfry, a feat that took 18 hours. It is 2.2 metres tall and 2.9 metres wide. However, in September 1859 it cracked under the hammer, a mere two months after it officially went in to service. According to the bell foundry’s manager the the clock designer had used a hammer more than twice the maximum weight specified. For three years Big Ben was taken out of commission and the hours were struck on the lowest of the quarter bells until it was reinstalled. To make the repair, a square piece of metal was chipped out from the rim around the crack, and the bell given an eighth of a turn so the new hammer struck in a different place. Big Ben has chimed with an odd twang ever since and is still in use today complete with the crack.
Despite Big Ben being one of the world’s most famous tourist attractions, the interior of the Clock Tower is not open to the general public due to security concerns, although from time to time the press and other VIPs are granted access. However, the tower has no lift [elevator], so those escorted must climb the 334 limestone stairs to the top. Because of changes in ground conditions since its construction (notably tunnelling for the Jubilee Line extension – one of the many London Underground lines), the tower leans slightly to the north-west, by roughly 8¾ inches [220 millimetres] at the clock face, giving an inclination of approximately 1/250. Due to thermal effects it oscillates annually by a few millimetres east and west.
On the 10th May 1941, a German bombing raid damaged two of the clock faces and sections of the tower’s stepped roof, and destroyed the House of Commons chamber in the Palace of Westminster. The replacement section was designed as a five-floor block. Two floors are occupied by the current camber which was used for the first time on the 26th October 1950. Despite the heavy bombing Big Ben ran accurately and chimed throughout the London Blitz . History repeated itself: in 1915/16 for two years during World War I, the bells were silenced and the clock face darkened at night to prevent attack by German Zeppelins. On the 1st September 1939, although the bells continued to chime, the clock faces were again darkened at night through the years of World War II to prevent guiding the bomber pilots of the German Luftwaffe in the Blitz.
Modern historical facts: On New Years Eve 1962 the clock slowed down due to heavy snow and ice on the long hands, causing the pendulum to detach from the clockwork, as it is designed to do in such circumstances to avoid serious damage elsewhere in the mechanism – the pendulum continued to swing freely. It therefore chimed in the New Year of 1963 ten minutes late! On the 5th August 1976 Big Ben suffered its first and only breakdown. The speed regulator of the chiming mechanism finally broke after 100+ years of metal fatigue, with the result that the fully-wound 4 ton weights dumped their entire potential energy into the chiming mechanism in one go. It caused a great deal of damage; the Great Clock was shut down for a total of 26 days over nine months – it was reactivated on the 9th May 1977; this was its longest break in operation since it was built.
On the 27th May 2005 the clock stopped at 10.07 pm local time, possibly doe to hot weather (temperatures in London had reached an unseasonal 90ºF [31.8ºC]. It restarted itself, but stopped again at 10.20 pm local time and remained still for about 90 minutes before restarting. Later that same year, on the 29th October 2005 the mechanism was stopped for about 33 hours so that the clock and its chimes could be worked on. It was the lengthiest maintenance shutdown in 22 years. At 7.00 am on the 5th June 2006 the clock tower’s “Quarter Bells” were taken out of commission for four weeks as a bearing holding one of the quarter bells was damaged from years of wear and needed to be removed for repairs. On the 11th August 2007 a 6-week stoppage for maintenance began. Bearings in the clock’s drive train and the “Great Bell” striker was replaced for the first time since installation. During the maintenance works, the clock was not driven by the original mechanism, but by an electric motor – so Big Ben continued to record the time, albeit silently!
With acknowledgement to Wikipedia, the Online Encyclopaedia, for this information.
A View of Big Ben and the Palace of Westminster with the River Thames in the foreground