The Bridges - Tower 1

[Kathrine Selvage]

TowerBridge is a Grade I listed combined bascule, suspension, and, until 1960, cantilever bridge[1] in London, built between 1886 and 1894, designed by Horace Jones and engineered by John Wolfe Barry with the help of Henry Marc Brunel.[2] It crosses the River Thames close to the Tower of London and is one of five London bridges owned and maintained by the City Bridge Foundation, a charitable trust founded in 1282.

The bridge was constructed to connect the 39 per cent of London's population that lived east of London Bridge, equivalent to the populations of "Manchester on the one side, and Liverpool on the other",[3] while allowing shipping to access the Pool of London between the Tower of London and London Bridge.

The bridge is 940 feet (290 m) in length including the abutments[4] and consists of two 213-foot (65 m) bridge towers connected at the upper level by two horizontal walkways, and a central pair of bascules that can open to allow shipping. Originally hydraulically powered, the operating mechanism was converted to an electro-hydraulic system in 1972. The bridge is part of the London Inner Ring Road and thus the boundary of the London congestion charge zone, and remains an important traffic route with 40,000 crossings every day. The bridge deck is freely accessible to both vehicles and pedestrians, whereas the bridge's twin towers, high-level walkways, and Victorian engine rooms form part of the Tower Bridge Exhibition.

Tower Bridge has become a recognisable London landmark. It is sometimes confused with London Bridge, about 0.5 miles (800 m) upstream, which has led to a persistent urban legend about an American purchasing the wrong bridge.

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.[5]

A Special Bridge or Subway Committee chaired by Sir Albert Joseph Altman was formed in December 1875 to find a solution.[6] On 7 December 1876, the Committee presented a report recommending a bridge or subway to the east of London Bridge should be constructed, funds permitting.[7]

More than fifty designs were submitted, including one from civil engineer Sir Joseph Bazalgette, which was rejected because of a lack of sufficient headroom. None of the designs gained support and it was not until 24 July 1884 that the Bridge House Estates Committee brought forward a report that proposed "a low level bridge, with mechanical opening or openings" be built.[7] Following a deputation from the Committee visiting Belgium, Holland, and Newcastle Bridge, a proposal was presented on 28 October 1884 to the Court of Common Council for a mechanical bridge built according to one of three models: Design A, a swing bridge; Design B, a variation of that swing bridge; and Design C a bascule bridge.[5][8] Design C was recommended and a bill was prepared to present to Parliament.[7]

The Act of Parliament authorising construction received royal assent on 14 August 1885 and is called the Corporation of London (Tower Bridge) Act 1885.[7] The Act was specific about the design of what it (and contemporary media) named "The Tower Bridge", rather than just "Tower Bridge". Key stipulations were:

Barry later noted that "at one time it was intended that the new works should be made suitable for the mounting of guns and for military occupation." But that "The latter idea was afterwards to a great extent discarded."[7] However, the Act provided for "the senior officer commanding in the Tower [of London]...shall at all times have...the right to occupy the Tower Bridge."

The extent of the maritime trade conducted at this time between the site of Tower Bridge and London Bridge (a distance of approximately 0.5 miles) is demonstrated in Schedule B of the Act which lists 11 active docks, quays and wharfs operating on the north side of the Thames, and 20 wharfs operating on the south side.

Two further Acts of Parliament were required to extend the time allowed to complete the works. On 12 August 1889 the Corporation of London (Tower Bridge) Act 1889 received royal assent to extend the time allowed for construction by a further four years to 1893 and make various adjustments to neighbouring streets that had proved necessary. The work was not yet complete after those four years, and on 29 June 1893 the Corporation of London (Tower Bridge) Extension of Time Act 1893 received royal assent extending the time by a further year.[10]

Construction was funded by the City Bridge Foundation, 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.[11]

Sir John Wolfe Barry was appointed engineer and Sir Horace Jones the architect (who, as the City Architect, was also one of the judges).[12][13] Jones and 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.[12]

Construction started on 22 April 1886,[7] with the foundation stone laid by the Prince of Wales on 21 June, and took eight years.[14][15] The work was divided into eight contracts. Mr (later Sir) John Jackson won three of those contracts and was responsible for the northern approach to the bridge (which started in February 1887), the foundations of the piers and the abutments of the bridge (started February 1887),[16] and the cast iron parapet for the northern approach (December 1887) at a total accepted tender cost of 189,732;[17] Sir W. G. Armstrong, Mitchell, and Co. Ltd, was awarded the hydraulics contract for which they tendered 85,232 (December 1887); Mr William Webster was responsible for the southern approach[18] at 38,383 (July 1888); Sir William Arrol & Co. had the contract for the metalwork of the superstructure[19] at 337,113 (May 1889), which amounted to about 12,100 tons;[4] Messrs Perry & Co won two contracts covering the masonry superstructure (May 1889), and paving and lighting (May 1892) for a total accepted tender of 179,455.[17] The total accepted tender for the eight contracts was 830,005.[17]

On average 432 people worked on the site,[4] although at least 1,200 worked on its construction overall and received invitations to the entertainment provided for the workmen at its opening.[20] Edward Cruttwell was the resident engineer throughout the period of construction.[21] Cruttwell noted that there were "only" ten fatal accidents during the construction: four in sinking the foundations, one on the approaches, and the remaining five on the superstructure.[4]

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.[22] The first caisson was started in September 1886 and it was not until January 1890 that both piers were complete. The reason for the long duration of the foundation works was the need to defer excavation of the second pier until the staging for the first pier had been removed to allow 160 feet of clear water-way for shipping.[23]

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, and achieve the stipulation that the bridge should fit architecturally with the Tower of London.[24]

Jones died in 1887, and Barry took over as architect. Barry later summarised the contributions to the construction of Tower Bridge: "Mr Fyson, who undertook much of the preparation of the detailed drawings; Mr Stevenson, who had been his assistant with the architectural work; and...most of all...Mr Cruttwell, the Resident Engineer, and Mr Homfray, who superintended the machinery."[3] Stevenson replaced Jones's original brick faade 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.[21][25] The total cost of construction was 1,184,000[15][21] (equivalent to 170 million in 2023).[26]

Tower Bridge was officially opened on 30 June 1894 by the Prince and Princess of Wales.[12][27] The opening ceremony was attended by the Lord Chamberlain, the Lord Carrington and the Home Secretary, H. H. Asquith.[15] It was reported that "few [pageants] have been more brilliant or will have a more abiding and historic interest" than the opening of Tower Bridge in the history of the City of London, and it was a "semi-State" occasion.[28]

In addition to the official opening, the City of London Corporation gave an "entertainment", at a cost of 300, to 1,200 workmen and their wives. Edward Cruttwell, who had been in charge of the building of the bridge from the beginning, presided. After dinner, each workman was presented with a commemorative pipe and packet of tobacco, and each workman's wife with a box of sweetmeats.[20]

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.[30][31] The walkway reopened in 1982 as part of the Tower Bridge Exhibition.[30][32]

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.[33] 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.[34]

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