Big Ben (renamed Elizabeth Tower in 2012 to mark the Diamond Jubilee of Elizabeth II) is the nickname for the Great Bell of the clock at the north end of the Palace of Westminster in London

---

BIG BEN & PALACE OF WESTMINISTER FROM THAMES RIVER BOAT CRUISE

---

---

BIG BEN & PALACE OF WESTMINISTER FROM AIR

---

---

BIG BEN & PALACE OF WESTMINISTER FROM GROUND

---

---

GENERAL INFORMATION

• The tower is a British cultural icon recognised all over the world
• It is one of the most prominent symbols of the United Kingdom and parliamentary democracy
• Establishing shot of films set in London
• The clock tower has been part of a Grade I listed building since 1970 and a UNESCO World Heritage Site since 1987

---

• Visit & Entry : The interior of the tower is not open to overseas visitors, though United Kingdom residents were able to arrange tours (well in advance) through their Member of Parliament
• Lift : However, the tower currently has no lift, though one is being installed, so those escorted had to climb the 334 limestone stairs to the top

---

• Type : Clock tower
• Architectural style : Gothic Revival
• Location : Westminster, London, England, UK
• Origin : was raised as a part of Charles Barry’s design for a new palace after the old Palace of Westminster was largely destroyed by fire on the night of 16 October 1834
• Completed : 31 May 1859; 160 years ago / 150th anniversary 31 May 2009
• Height : 96 metres
• Steps : Climb from ground level to the belfry is 334 steps
• Base : Square (12 m on each side). The tower is founded on a 15.2 m square raft, made of 3.0 m thick concrete at a depth of 4.0 m below ground level.
• The bottom 61.0 m of the tower’s structure consists of brickwork with sand-coloured Anston limestone cladding.
• The remainder of the tower’s height is a framed spire of cast iron
• The interior volume of the tower is 4650 cubic metres
• Floor count : 11
• Design and construction Architect : Augustus Pugin

---

CLOCK

---

• Dials of the clock are set in an iron frame 7.0 m in diameter
• The iron frame supporting 312 pieces of opal 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 dial 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 hour hand is 2.7 m long & the minute hand is 4.3 m long
• Big Ben is the largest of the tower’s five bells and weighs 13.7 tonnes
• Four quarter bells chime at 15, 30 and 45 minutes past the hour and just before Big Ben tolls on the hour
• The clock uses its original Victorian mechanism, but an electric motor can be used as a backup.
• The clock dials are 23 feet (7.0 m) in diameter
• Unlike most other Roman numeral clock dials, which show the ‘4’ position as IIII, the Great Clock faces depict ‘4’ as IV.
• The four clock dials are 54.9 m above ground

---

CLOCK MOVEMENT

---

• The clock’s movement is famous for its reliability. The designers were the lawyer and amateur horologist Edmund Beckett Denison, and George Airy, the Astronomer Royal
• Construction was entrusted to clockmaker Edward John Dent ; after his death in 1853 his stepson Frederick Dent completed the work, in 1854
• As the tower was not complete until 1859 – Denison had time to experiment : instead of using the deadbeat escapement and remontoire as originally designed, Denison invented the double three-legged gravity escapement
• This escapement provides the best separation between pendulum and clock mechanism
• The pendulum is installed within an enclosed windproof box beneath the clockroom
• It is 13 feet (4.0 m) long, weighs 660 pounds (300 kg), suspended on a strip of spring steel ​¹⁄₆₄ inch (0.40 mm) in thickness and beats every two seconds
• The clockwork mechanism in a room below weighs five tons.

• On top of the pendulum is a small stack of old penny coins ; these are to adjust the time of the clock
• Adding a coin has the effect of minutely lifting the position of the pendulum’s centre of mass, reducing the effective length of the pendulum rod and hence increasing the rate at which the pendulum swings
• Adding or removing a penny will change the clock’s speed by 0.4 seconds per day
• The clock is hand wound (taking about 1.5 hours) three times a week
• On 10 May 1941, a German bombing raid damaged two of the clock’s dials and sections of the tower’s stepped roof and destroyed the House of Commons chamber
• Architect Sir Giles Gilbert Scott designed a new five-floor block
• Two floors are occupied by the current chamber, which was used for the first time on 26 October 1950
• The clock ran accurately and chimed throughout the Blitz

---

BELLS

---

Great Bell

---

• The main bell, officially known as the Great Bell but better known as Big Ben, is the largest bell in the tower and part of the Great Clock of Westminster – It sounds an E-natural
• The original bell was a 16 ton (16.3-tonne) hour bell, cast on 6 August 1856 in Stockton-on-Tees by John Warner & Sons
• It is thought that the bell was originally to be called Victoria or Royal Victoria in honour of Queen Victoria, but that an MP suggested the bell’s current nickname of “Big Ben” during a Parliamentary debate; the comment is not recorded in Hansard
• Since the tower was not yet finished, the bell was mounted in New Palace Yard but, during testing it cracked beyond repair and a replacement had to be made
• The bell was recast on 10 April 1858 at the Whitechapel Bell Foundry as a 131/2 ton (13.76-tonne) bell
• The second bell was transported from the foundry to the tower on a trolley drawn by sixteen horses, with crowds cheering its progress
• It was then pulled 200 ft (61.0 m) up to the Clock Tower’s belfry, a feat that took 18 hours
• It is 7 feet 6 inches (2.29 m) tall and 9 feet (2.74 m) diameter
• This new bell first chimed in July 1859
• In September it too cracked under the hammer
• According to the foundry’s manager, George Mears, the horologist Denison 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 repaired
• 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 a slightly different tone ever since, and is still in use today with the crack unrepaired
• Big Ben was the largest bell in the British Isles until “Great Paul”, a 163/4 ton (17 tonne) bell currently hung in St Paul’s Cathedral, was cast in 1881

---

Chimes

---

• The quarter bells play a once-repeating, 20-note sequence of rounds and four changes in the key of E major : 1–4 at quarter past, 5–12 at half past, 13–20 and 1–4 at quarter to, and 5–20 on the hour (which sounds 25 seconds before the main bell tolls the hour)
• Because the low bell (B) is struck twice in quick succession, there is not enough time to pull a hammer back, and it is supplied with two wrench hammers on opposite sides of the bell
• The tune is that of the Cambridge Chimes, first used for the chimes of Great St Mary’s church, Cambridge, and supposedly a variation, attributed to William Crotch, based on violin phrases from the air “I know that my Redeemer liveth” in Handel’s Messiah
• The notional words of the chime, again derived from Great St Mary’s and in turn an allusion to Psalm 37:23–24, are : “All through this hour/Lord be my guide/And by Thy power/No foot shall slide”. They are written on a plaque on the wall of the clock room
• One of the requirements for the clock was that the first stroke of the hour bell should be correct to within one second per day. The tolerance is with reference to Greenwich Mean Time (BST in summer)
• So, at twelve o’clock, for example, it is the first of the twelve hour-bell strikes that signifies the hour (the New Year on New Year’s Eve at midnight)
• The time signalled by the last of the “six pips” (UTC) may be fractionally different

---

• Due to changes in ground conditions since construction, the tower leans slightly to the north-west, by roughly 230 millimetres over 55 m height, giving an inclination of approximately ​1⁄240
• This includes a planned maximum of 22 mm increased tilt due to tunnelling for the Jubilee line extension.
• It leans by about 500 millimetres (20 in) at the finial.
• Experts believe the tower’s lean will not be a problem for another 4,000 to 10,000 years
• Due to thermal effects it oscillates annually by a few millimetres east and west.

---

CULTURAL SIGNIFICANCE OF BIG BEN

---

Double-decker buses frame a busy Whitehall with Big Ben in the background

• The clock has become a cultural symbol of the United Kingdom, particularly in the visual media
• When a television or film-maker wishes to indicate a generic location in the country, a popular way to do so is to show an image of the tower, often with a red double-decker bus or black cab in the foreground
• In 2008, a survey of 2,000 people found that the tower was the most popular landmark in the United Kingdom
• It has also been named as the most iconic film location in London
• The sound of the clock chiming has also been used this way in audio media, but as the Westminster Quarters are heard from other clocks and other devices, the sound is by no means unique
• Big Ben is a focal point of New Year celebrations in the United Kingdom, with radio and television stations airing its chimes to welcome the start of the New Year
• To welcome in 2012, the clock tower was lit with fireworks that exploded at every toll of Big Ben
• Similarly, on Remembrance Day, the chimes of Big Ben are broadcast to mark the 11th hour of the 11th day of the 11th month and the start of the two minutes’ silence
• The chimes of Big Ben have also been used at the state funerals of monarchs on three occasions
• Firstly, at the funeral of King Edward VII in 1910, when Big Ben chimed 68 times, one stroke for each year of the monarch’s life
• Secondly, at the funeral of King George V in 1936 (70 strokes)
• Finally, at the funeral of King George VI in 1952 (56 strokes)
• Londoners who live an appropriate distance from the tower and Big Ben can, by means of listening to the chimes both live and on analogue radio, hear the bell strike thirteen times
• This is possible because the electronically transmitted chimes arrive virtually instantaneously, while the “live” sound is delayed travelling through the air since the speed of sound is relatively slow
• ITN’s News at Ten opening sequence formerly featured an image of the tower with the sound of Big Ben’s chimes punctuating the announcement of the news headlines of the day
• The Big Ben chimes (known within ITN as “The Bongs”) continue to be used during the headlines and all ITV News bulletins use a graphic based on the Westminster clock dial
• Big Ben can also be heard striking the hour before some news bulletins on BBC Radio 4 (6 p.m. and midnight, plus 10 p.m. on Sundays) and the BBC World Service, a practice that began on 31 December 1923
• The sound of the chimes is sent live from a microphone permanently installed in the tower and connected by line to Broadcasting House
• At the close of the polls for the 2010 general election the results of the national exit poll were projected onto the south side of the tower
• On 27 July 2012, starting at 8:12 a.m, Big Ben chimed 30 times, to welcome the Games of the 30th Olympiad, which officially began that day, to London

---

2017 RENOVATION

---

• On 21 August 2017, Big Ben’s chimes were silenced for four years to allow essential restoration work to be carried out on the tower
• The decision to silence the bells was made to protect the hearing of the workers on the tower, and drew much criticism from senior MPs and Prime Minister Theresa May
• The striking and tolling of the bells for important occasions, such as New Year’s Eve and Remembrance Sunday, will be handled via an electric motor ; and at least one of the four clock faces will remain visible during the restoration
• Scaffolding was put up around the tower immediately after the bells were silenced
• The original cost of the project to the taxpayers and creditors was estimated to be roughly £29 million, but this was then more than doubled, to £69 million
• Big Ben will resume its usual striking and tolling in 2021
• The aim of the renovation is to repair and conserve the tower, upgrading facilities as necessary, and ensuring the tower’s integrity for future generations
• The last significant renovation work to the tower was carried out in 1983–85
• The 96-metre (315 ft) high structure is exposed to the elements, resulting in cracks and other damage to the masonry and rust damage to the ironwork
• The 2567 cast-iron roof tiles will be removed and replaced
• A lift will be installed to make access easier, along with a basic washroom with running water
• The Ayrton Light at the top of the tower, which is lit when Parliament is sitting, will also be fully dismantled and restored with the other lights in the Belfry, the lights being replaced with low energy LEDs
• One of the most visible changes to the tower will be the restoration of the clock-face framework to its original colour of Prussian blue, used when the tower was first built in 1859, with the black paint used to cover up the soot-stained dial frames being stripped away
• The clock faces are also to be regilded, and the shields of St George are to be repainted in their original red and white colours
• The 1,296 pieces of glass that make up the clock faces are also to be removed and replaced