Short History - Big Ben

Great Clock of Westminster

 

The clock tower at the Houses of Parliament has become the symbol of Britain, and the mellow tones of the bells are known and loved throughout the world, yet the clock was built against a background of controversy - indeed so bitter were the arguments and so long the delays involving construction, the wonder must be that it was ever completed.

The idea for the clock came about in the 1830s when the ancient Palace of Westminster was destroyed by fire and plans for the new Houses of Parliament incorporated a clock on the northern tower. The Astronomer Royal, George Airy, was appointed referee for the design and construction of the clock and a contract was let to Edward Dent who had recently completed a clock at the Royal Exchange. The Astronomer Royal's specification required that the first blow of each hour should be struck within a second of the time, and there was considerable feeling among the clock-making fraternity that such accuracy could not be maintained in a large turret clock where four sets of very heavy hands are subject to all weathers.

That such accurate running was achieved is due largely to the inventive genius of Edmund Beckett Denison, later to become Lord Grimthorpe, whose double three-legged gravity escapement was considered the greatest advance in horological design for many centuries and has since been adopted for most turret clocks. An interesting and comprehensive account of the clock's history and of the many difficulties and disagreements encountered by the various personalities involved has been written by John Darwin,[1] former Resident Engineer at the Palace of Westminster. There has been some speculation over the years regarding the naming of the bell, the most popular explanation being that it was named after Sir Benjamin Hall, the Commissioner of Works. The story relates that the Commons were debating the issue and Sir Benjamin, a man of considerable proportions, was replying on behalf of the government when a back bencher exclaimed, 'Why not call it Big Ben?' and the name stuck. Unfortunately there is no record of this in Hansard.

The bell was cast but never reached the belfry since it cracked while being struck experimentally in New Palace Yard. A new bell was made from the metal of the old and on 1859 May 30 the clock was started with hands on just two of the dials. The remaining hands were soon fitted and in July the clock began striking the hours. The chiming mechanism was brought into use in early September and at the beginning of October the hour bell cracked. Thus the clock was operating in its originally intended form for less than a month. For the next three years the hours were struck on the largest of the quarter bells, after which the hour bell was brought back into use, having been put through a quarter of a turn so that the damaged surface is away from the hammer. It is this crack which gives Big Ben its characteristic tone.

The music of the chimes is taken from Handel's Messiah. It is an extension of a phrase in the aria 'I know that my Redeemer liveth'. Introduced towards the end of the eighteenth century for the clock at St Mary's Church in Cambridge,[2] and known originally as the Cambridge Quarters, the passages have become familiar as the Westminster Chimes. In 1924, daily radio broadcasts of the bells were begun, and with a few interruptions, they have continued ever since. During that time the bells have heralded many events of national importance, announcing both the nation's joy and the nation's grief. When the clock underwent major overhauls in 1934 and 1956, radio duties were taken up by Great Tom of St Paul's. In 1976, metal fatigue almost tore the mechanism apart, and, once again the St Paul's clock proved an admirable deputy on the air. So great was the damage that consideration was given to replacement rather than repair. Fortunately repair was possible and the clock was returned to full working order in time for the Queen's visit to the Palace on the occasion of her Silver Jubilee in 1977.

Recently I was privileged to visit the clock-room and bells. To stand in the belfry at the Palace of Westminster at 12 o'clock must be every horologist's dream. It is well worth climbing the three hundred steps to make that dream come true.

by Mr Peter Macdonald
46 Vista Way, Harrow, Middx. HA3 0SL

[1] Darwin J., The Triumphs of Big Ben, Robert Hale, 1986
[2] 'The Song of the Hours', Horological Journal, 999, 378 (1941)

 

 

The 1976 Disaster

 

Londoners are accustomed to hearing Big Ben strike the hour - but in 1976 disaster struck instead. The wrought iron tubular shaft of the fly-governor controlling the speed of the quarter-chiming mechanism was suffering fatigue, and on 5th August 1976 it failed suddenly as it was striking at 3.45 am. This allowed the 1.250kg driving weight to fall 50 metres to the ground, forcing the chiming mechanism and the cast iron gears to operate much faster than usual. The bearings disintegrated and broke the cast-iron frame of the clock.

AEA Technology was called in by the National Physical Laboratory to carry out NDT examination of the remainder of the clock assembly. The damage was extensive, as parts of the mechanism had been projected through the ceiling into the room above. However, close examination revealed that although some fractures were caused by impact, other components had contained fatigue or fracture damage prior to the failure of the clock.

Testing methods appropriate to the site had to be chosen: access to the clock chamber was limited and all equipment had to be hauled up by rope to the tower.

During the final weekend when the clock was stopped for 36 hours to allow testing of the moving parts, the NDT team elected to sleep in the tower: the climb up and down the 290 steps was wearing them out! Two camp beds were installed in a room some 10 metres below the clock room. It was very cold, and the noise from passing traffic was considerable; but, with the clock stopped, they did not have to endure the deafening peals of the bell and quarter-hour chimes or, worse, the ratchet mechanism resetting itself every fifteen minutes.

Since then AEA Technology has inspected the clock annually in October (when the clock is stopped to change from British Summer Time to Greenwich Mean Time).

No. 60 December 1997
AEA Technology

 

 


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