The clock inside the tower was the world's largest when it was installed in the middle of the 19th century. The name Big Ben actually refers to the clock's hour bell, the largest of the clock's five bells. The other four are used as quarter bells.
Big Ben
There were two bells cast as the clock tower's hour bell. A first, 16 ton weighing bell was cast by John Warner and Sons in 1856. Since the Clock Tower was not yet completed, the bell was hung temporarily in the Palace Yard. The bell soon cracked so it was recast in 1858 in the Whitechapel Bell Foundry as a 13.5 ton bell. Unfortunately soon after this bell was placed in the belfry in July 1859, it cracked as well. This time, instead of yet again recasting the bell, the crack was repaired and a lighter hammer was used to prevent any more cracks.
The hour bell was probably named after Benjamin Hall, the First Commissioner of Works. Some sources however claim the bell was named after Benjamin Caunt, a British heavyweight boxing champion.
The Clock
The clock was the largest in the world and is still the largest in Great-Britain. The clock faces have a diameter of almost 25ft (7.5m). The hour hand is 9ft or 2.7m long and the minute hand measures 14ft (4.25m) long.
The clock is known for its reliability, it has rarely failed during its long life span. Even after the nearby House of Commons was destroyed by bombing during World War II, the clock kept on chiming. The clock's mechanism, designed by Edmund Beckett Denison, has a remarkable accuracy. The clock's rate is adjusted by simply adding small pennies on the shoulder of the pendulum.
The Tower
The tower was constructed between 1843 and 1858 as the clock tower of the Palace of Westminster. The palace is now better known as the Houses of Parliament.
The clock tower rises 316ft high (96m) and consists of a 200ft (61m) high brick shaft topped by a cast iron framed spire. The clock faces are 180ft / 55m above ground level.
History of Big Ben or Clock Tower
The Beginning
On the night of the 16th of October, 1834 the old Palace of Westminster was destroyed by fire. It is said that Charles Barry, an architect, was returning to London from Brighton, where he had designed a church, saw the glow of the fire in the distance and discovered that the Houses of Parliament were on fire. Following the destruction of the buildings, a competition was launched for design suitable for the new Palace. Charles Barry's design won.
Charles Barry's design incorporated a clock tower. The dials were to be thirty feet in diameter, the quarter chimes were to be struck on eight bells, and the hours were to be struck on a 14 ton bell. Barry invited Benjamin Lewis Vulliamy, a clockmaker of reputation, to submit a design and price for constructing such a clock. No doubt Vulliamy was pleased to be the clockmaker of choice for what was then to be the largest clock in the world, but other enterprising firms were not happy with the manner in which they had no opportunity to compete for the contract. Subsequently, the Astronomer Royal, Sir George Airy, was appointed as referee for the new clock and produced a specification in 1846. A key requirement of the specification was that the clock was to strike the first blow of each hour correct to one second in time. Tenders were invited and were received from three makers, Dent, Vulliamy and Whitehurst.
It was clear that Airy favoured Dent, with whom he had worked on the development of the chronometer. In 1849 the famous horologist, Edmund Beckett Denison (later Lord Grimthorpe) was appointed co-referee with Airy. Denison was in agreement with Airy that Dent was the maker most capable of constructing the clock and they produced a revised specification and drawings, in respect of which Dent was requested to revise his estimate. In 1852 Dent was awarded the contract.
Early troubles
The first of the difficulties occurred when it was discovered that the architect had failed to make the necessary provision for the clock in the tower. Denison certainly had the ability to propel the project forward, but he lacked any diplomatic skill and the tension which existed between him and Barry precluded any compromise by the architect. It was necessary instead for the clock to be modified so that it would fit within the internal walls.
Edward John Dent died in 1853 and the clock mechanism was completed by his stepson Frederick Rippon (who changed his name to Frederick Dent). In 1854 the mechanism was ready to be installed in the tower but this was not possible as the tower was incomplete. Denison was therefore able to spend a number of years testing out different types of escapement on the mechanism as it operated in Dent's workshop. It was during this period that he invented the double three-legged gravity escapement which enables the clock to keep such accurate time.
Denison was also invited to produce a specification for, and referee, the casting of the bells. The contract was let to John Warner and Sons who cast the hour bell in 1856. The tower was not yet ready to receive the bell so upon delivery it was mounted in the New Palace Yard where it was struck regularly for the benefit of the public. This bell weighed about 16 tons, which was two tons heavier than intended. To compensate for this, Denison increased the weight of the ball hammer from 4 to 6 cwt. This was not a wise move, and one year later in 1857, the great bell cracked irreparably while being struck by this hammer. Denison proclaimed the casting as faulty but the manufacturers denied this and claimed it was his fault for using too heavy a hammer. George Mears of the Whitechapel Bell Foundry was given the contract to recast the bell from the metal of the old in 1858 which he did successfully, producing a bell weighing 13.5 tons which is the one in use today. The four quarter bells were cast by Warners.
The name 'Big Ben' was first applied to the original hour bell cast by Warners. There is no firm evidence of the origin of this name, but it may have derived from Sir Benjamin Hall, Commissioner of Works who was involved with the project and who was a man of considerable size. The name was also applied to the recast hour bell and has since come to indicate not just the bell, but also the clock and the clocktower.
Yet more difficulties...
When the five bells were installed in the tower in 1858, it was possible to install the clock mechanism in the clockroom beneath the belfry. The next difficulty arose over the hands for the dials of the clock. The original hands were designed and manufactured on behalf of Charles Barry but were too heavy for the clock to be able to operate with them. Denison requested Barry to have the hands remade, but when this was done it was found that the hands installed on the dials were heavier that the previous ones! The clock still could not function correctly, so Denison obtained permission for Dents to construct minute hands to his design. These minute hands are the ones in use today, the hour hands being from Charles Barry's second attempt. With the hands operating satisfactorily it was now possible to commence the chiming and hour striking so the clock became fully operational on the 7th of September 1859.
This pleasant situation was short lived. Less than one month later, the great hour bell cracked while being struck by the same 6 cwt. hammer that ruined the original bell. A fierce dispute ensued between Denison and Mears, the bell founder, which culminated with Denison being sued for libel by Mears. The hours were struck on the largest of the quarter bells for two years while the argument was going on. Eventually chemical analysis of the bell metal proved Denison right, but it was not considered feasible to have the bell recast for the second time. Instead, the bell was given a quarter turn to move the crack away from the point of the hammer's strike and a lighter hammer was substituted. Thus in 1862, striking of the hour bell resumed.
At last
The next 114 years of the clock's history were relatively serene and Big Ben soon developed a reputation for great accuracy. In 1906, the gas lighting of the dials was replaced by electric lighting. Electric winding of the clock was introduced in 1912. The mechanism was overhauled in 1934 and 1956.
The first radio broadcast of Big Ben was made by the BBC at midnight on the 31st of December 1923 to welcome in the new year. Shortly afterwards, a permanent microphone installation enabled regular broadcasts of the chimes and the bell to function effectively as a time signal. The broadcasting of the bells on the BBC World Service assumed particular importance during the Second World War, when the sounds were a source of comfort and hope to those hoping that Britain would not be overcome.
Big Ben is still broadcast today on BBC Radio 4 at certain times.
Disaster
However, in 1976 a completely unanticipated event occurred which almost caused the complete destruction of the clock. At 3:45am on the 5th of August 1976 as the clock started to chime, metal fatigue in the shaft connecting the chiming train to its fly fan caused the shaft to break. Without the retarding and braking effect of the fly, the chiming mechanism, propelled by the 1.25 ton weight in the shaft, increased its speed of rotation dramatically. This led to the total destruction of the chiming mechanism, with various components and fragments of others being scattered about the clockroom. Some pieces of machinery were flung at the ceiling with sufficient force to penetrate to the room above. The cast iron frame was fractured and collapsed onto the winding motor below. The flying debris also caused damage to the going and striking trains.
It was necessary for the chiming train to be reconstructed from scratch. The magnitude of this task meant that other options, such as replacement with an electric motor, were considered. The reconstruction took almost one year to complete.
The sounds of Big Ben have traditionally been the focus of the entry of the New Year. In December 1999 they were of particular significance, marking the beginning of the new Millennium. The sounds of the chimes were relayed on television and radio broadcasts and to the crowd assembled in the Millennium Dome. For the first time also, cameras were located in the belfry so that viewers could see as well as hear the chimes and twelve o'clock being struck on the bells.
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