Elevation, with dimensions

In the late 19th century, commercial development in the East End of London increased, leading to demand for a new river crossing downstream of London Bridge. A traditional fixed bridge at street level could not be built because it would cut off access by sailing ships to the port facilities in the Pool of London between London Bridge and the Tower of London.[1]

A Special Bridge or Subway Committee chaired by Sir Albert Joseph Altman was formed in 1877 to find a solution.[2] More than fifty designs were submitted, including one from civil engineer Sir Joseph Bazalgette, which was rejected because of a lack of sufficient headroom. A design was not approved until 1884 when it was decided to build a bascule bridge.[1][3] Sir John Wolfe Barry was appointed engineer and Sir Horace Jones the architect (who was also one of the judges).[4][5] An Act of Parliament authorising construction was passed in 1885. It specified that the opening span would provide a clear width of 200 feet (61 m) and headroom of 135 feet (41 m). The design had to be in a Gothic style.[4] Construction was funded by the Bridge House Estates, a charity established in 1282 for maintenance of London Bridge that subsequently expanded to cover Tower Bridge, Blackfriars Bridge, Southwark Bridge and the Millennium Bridge.[6]

Barry designed a bridge with two bridge towers built on piers. The central span was split into two equal bascules or leaves, which could be raised to allow river traffic to pass. The two side spans were suspension bridges, with rods anchored both at the abutments and through rods contained in the bridge's upper walkways.[4]

 

Tower Bridge under construction, 1892

Construction started in 1886, with the foundation stone laid by the Prince of Wales on 21 June, and took eight years.[7][8] Major contractors included Sir John Jackson (foundations),[9] Armstrong, Mitchell and Company (hydraulics), William Webster,[10] and Sir William Arrol & Co.[11] 432 people worked on the site; E W Crutwell was the resident engineer for the construction.[12]

Two piers, containing over 70,000 long tons (78,400 short tons; 71,123 t) of concrete, were sunk into the riverbed to support the construction.[13] More than 11,000 long tons (12,320 short tons; 11,177 t) of steel were used in the framework for the towers and walkways, which were then clad in Cornish granite and Portland stone to protect the underlying steelwork.[14]

Jones died in 1887, and George D. Stevenson took over the project.[15] Stevenson replaced Jones's original brick façade with the more ornate Victorian Gothic style, which made the bridge a distinctive landmark and was intended to harmonise the bridge with the nearby Tower of London.[12][15] The total cost of construction was £1,184,000[8][12] (equivalent to £143 million in 2021).[16]

 

1895 painting of the opening of Tower Bridge, William Lionel Wyllie

Tower Bridge was officially opened on 30 June 1894 by the Prince and Princess of Wales.[4][17] The opening ceremony was attended by the Lord Chamberlain, the Lord Carrington and the Home Secretary, H. H. Asquith.[8] An Act of Parliament stipulated that a tug boat should be on station to assist vessels in danger when crossing the bridge, a requirement that remained in place until the 1960s.[17]

The bridge connected Iron Gate, on the north bank of the river, with Horselydown Lane, on the south – now known as Tower Bridge Approach and Tower Bridge Road, respectively.[12] Until the bridge was opened, the Tower Subway – 0.25 mi (400 m) to the west – was the shortest way to cross the river from Tower Hill to Tooley Street in Southwark. Opened in 1870, Tower Subway was among the world's earliest underground ("tube") railways, but it closed after just three months and was reopened as a tolled pedestrian foot tunnel. Once Tower Bridge was open, the majority of foot traffic transferred to using the bridge, as there was no toll to cross. Having lost most of its income, the tunnel was closed in 1898.[18]

The high-level open-air walkways between the towers gained a reputation for prostitutes and pickpockets. Since they were only accessible by stairs, the walkways were seldom used by regular pedestrians and were closed in 1910.[19][20] The walkway reopened in 1982 as part of the Tower Bridge Exhibition.[19][21]

 

Tower Bridge during the first mass air raid on London, 7 September 1940

 

Tower Bridge – 1950, BW Lee

 

A Short Sunderland of No. 201 Squadron RAF moored at Tower Bridge during the 1956 commemoration of the Battle of Britain

During the Second World War, Tower Bridge was seen as a major transport link to the Port of London, and consequently was a target for enemy action. In 1940, the high-level span took a direct hit, severing the hydraulic mechanism and taking the bridge out of action. In April 1941, a parachute mine exploded close to the bridge, causing serious damage to the bascule, towers, and engine room. In 1942, a third engine was installed in case the existing ones were damaged by enemy action.[22] It was a 150 hp horizontal cross-compound engine, built by Vickers Armstrong Ltd. at their Elswick works in Newcastle upon Tyne. It was fitted with a flywheel having a 9-foot (2.7 m) diameter and weighing 9 tons, and was governed to a speed of 30 rpm. The engine became redundant when the rest of the system was modernised in 1974 and was donated to the Forncett Industrial Steam Museum by the City of London Corporation.[23]

The southern section of the bridge, in the London Borough of Southwark, was Grade I listed on 6 December 1949.[24] The remainder of the bridge, in the London Borough of Tower Hamlets, was listed on 27 September 1973.[25] In 1974, the original operating mechanism was largely replaced by a new electro-hydraulic drive system, designed by BHA Cromwell House, with the original final pinions driven by modern hydraulic motors.[26][27]

In 1982, the Tower Bridge Exhibition opened, housed in the bridge's twin towers, the long-closed high-level walkways, and the Victorian engine rooms. The latter still houses the original steam engines and some of the original hydraulic machinery.[28][29][30]

The bridge closed for a month in 2000 to repair the bascules and perform other maintenance.[31] A computer system was installed to control the raising and lowering of the bascules remotely. However, the system proved unreliable, resulting in the bridge being stuck in the open or closed positions on several occasions during 2005 until its sensors were replaced.[32]

In April 2008, authorities announced that the bridge would undergo a £4 million refurbishment that would take four years to complete. The work entailed stripping existing paint down to bare metal and repainting in blue and white.[33][34] Before this, the bridge's colour scheme dated from 1977, when it was painted red, white, and blue for Queen Elizabeth II's Silver Jubilee. Its colours were subsequently restored to blue and white.[33][34] Each section was enshrouded in scaffolding and plastic sheeting to prevent the old paint falling into the Thames and causing pollution. Starting in mid-2008, contractors worked on a quarter of the bridge at a time to minimise disruption, but some road closures were inevitable. The completed work should stand for 25 years.[35] The renovation of the walkway interior was completed in mid-2009. The renovation of the four suspension chains was completed in March 2010 using a state-of-the-art coating system requiring up to six different layers of paint.[33] A lighting system based on RGB LED luminaires was installed, concealed within the bridge superstructure, and attached without drilling holes, owing to the bridge's Grade I listing.[36]

 

Tower Bridge with Olympic Rings during the 2012 London Olympics

On 8 July 2012, as part of the London Olympics, the west walkway was transformed into a 200-foot-long (61 m) Live Music Sculpture by the British composer Samuel Bordoli. 30 classical musicians were arranged along the length of the bridge 138 feet (42 m) above the Thames behind the Olympic rings. The sound travelled backward and forwards along the walkway, echoing the structure of the bridge.[37][38]

Following the Olympics, the rings were removed from Tower Bridge and replaced by the emblem of the Paralympic Games for the 2012 Summer Paralympics.[39]

In 2016, Tower Bridge was closed to all road traffic from 1 October to 30 December.[40] This was to allow structural maintenance work to take place on the timber decking, lifting mechanism and waterproofing the brick arches on the bridge's approaches. During this, the bridge was still open to waterborne traffic. It was open to pedestrians for all but three weekends when free ferry service was in operation.[41]