Tower Bridge is the combined bascule and suspension bridge that crosses the River Thames beside the Tower of London. It was built between 1886 and 1894 to John Wolfe Barry's engineering and Horace Jones's Gothic design, and it still raises its two 1,000-tonne-plus road leaves (bascules) to let tall ships into the Pool of London.
The bridge now carries about 40,000 people a day, but getting it built took nearly two decades of argument, three Acts of Parliament and eight years of work in a crowded tidal river. Its story makes most sense told in order.
A Crossing the East End Needed, Without Closing the Pool (1870s–1884)
By the 1870s London Bridge was the lowest fixed crossing on the Thames, and everything downstream of it belonged to shipping. Roughly 39 percent of London's population lived east of London Bridge, a crowd a contemporary compared to the populations of "Manchester on the one side, and Liverpool on the other." To cross, they detoured west to London Bridge or paid a toll to walk through the Tower Subway, an iron tunnel opened in 1870.
A fixed bridge near the Tower would have cut off the Pool of London, the half-mile reach above it, where the 1885 Act lists 11 working docks, quays and wharves on the north bank and 20 on the south. Tall-masted ships had to reach them.
The City of London formed a Special Bridge or Subway Committee, chaired by Sir Albert Joseph Altman, in December 1875. On 7 December 1876 it reported that a bridge or a subway east of London Bridge should be built, funds permitting. More than fifty designs followed. Sir Joseph Bazalgette's was rejected for lacking headroom. None won support. It was not until 24 July 1884 that the Bridge House Estates Committee recommended "a low level bridge, with mechanical opening or openings."
From Jones's Arch to Barry's Level Walkways (1884–1885)
After visiting opening bridges in Belgium, the Netherlands and Newcastle, the committee put three options to the Court of Common Council on 28 October 1884: two swing bridges and a bascule bridge, Design C. The bascule won.
Horace Jones, the City Architect, had drawn the original scheme. It crossed the central span with an overhead arch, which ship owners said masts and rigging would foul. In 1885 John Wolfe Barry joined as engineer and replaced the arch with a "level soffit for the upper bridge": two straight high-level walkways between the towers.
The Corporation of London (Tower Bridge) Act 1885 received royal assent on 14 August 1885. The central opening had to give 200 feet (61 m) of clear width, 135 feet of headroom above high water when open and 29 feet when shut. A 160-foot channel had to stay open throughout construction, and the design had to "accord with the architecture of the Tower of London." Ships were to pass at any time, however long road traffic waited. The Act allowed four years; it took twice that, and Acts of 1889 and 1893 extended the deadline.
Eight Years in a Working River (1886–1894)
Work began on 22 April 1886, and the Prince of Wales laid the foundation stone on 21 June. The job was split into eight contracts. John Jackson sank the foundations. Sir William Arrol & Co., who were building the Forth Bridge in Scotland at the same time, supplied the steel superstructure. Armstrong, Mitchell and Co. of Newcastle won the hydraulic machinery contract, and Perry & Co. did the masonry. Edward Cruttwell was resident engineer throughout.
The foundations were the slowest part. Each of the two river piers holds more than 70,000 tons of concrete, sunk inside caissons. Because the 160-foot channel had to stay open, the second pier waited until the first pier's staging was cleared; the piers took from September 1886 to January 1890.
Above water, more than 11,000 tons of steel form the skeletons of the towers and walkways, clad in Cornish granite and Portland stone to protect it and to satisfy the Act. Horace Jones died in 1887. His assistant George Stevenson replaced Jones's plainer brick facade with the richer Victorian Gothic stonework that defines the bridge. An average of 432 people worked on site; ten were killed.
The Prince and Princess of Wales opened the bridge on 30 June 1894. The final cost was £1,184,000, equal to roughly £133 million in 2025 money. Each of some 1,200 workmen received a commemorative pipe and tobacco at a celebration dinner.
Water Under Pressure: How the Bascules Rose (1894–1976)
The 200-foot central span is two bascules, each projecting 100 feet over the river and extending another 62 feet 6 inches back inside its pier. Including ballast and paving, each weighs about 1,070 tons. Counterweights mean little force is needed to tip them. Barry gave their arc as 82 degrees, although guidebooks often quote 86. The side spans, each 270 feet long, are suspension bridges. The overall length is 940 feet (about 290 m) including the abutments, or about 244 m between the shore towers. The main towers rise 65 m (213 ft).
Steam engines in the engine rooms pumped water at 750 psi into six hydraulic accumulators. (weighted rams that stored pressure). That water drove engines in each pier, which turned pinions against toothed racks on the bascules. Each pier had two pairs, for redundancy. In the first twelve months the bascules were raised 6,160 times, about seventeen times a day, and each lift held up road traffic for an average of six minutes.
The water system ran for eight decades. A replacement electro-hydraulic drive, with oil instead of water as the working fluid, was begun in 1974. Most accounts date its completion to 1976, though some sources give 1972. Only the final pinions of the Victorian drive remain in use; the steam engines were kept for display.
A Locked Walkway, a Leaping Bus and a Bridge Under Fire (1910–1982)
The high-level walkways were meant to let pedestrians cross while the bascules were up. Most people preferred waiting to climbing the stairs, the walkways gained a reputation for pickpockets and prostitutes, and they closed in 1910.
In the Second World War, in 1940, a hit on the high-level span cut the hydraulic mains and put the bridge out of action. In April 1941 a parachute mine damaged a bascule, the towers and an engine room. A third steam engine was installed in 1942 as a spare.
The bridge's best-known story came on 30 December 1952. The relief watchman on duty failed to stop traffic before a lift, and the south bascule began to rise under a number 78 double-decker bus. Its driver, Albert Gunter, accelerated and cleared a drop of about 6 feet (1.8 m) onto the north bascule, which had not yet moved. The conductor broke a leg and twelve of the twenty passengers had minor injuries. Gunter was given a £10 bonus.
In 1960 the walkways, originally cantilevers, were strengthened with suspension cables. Red, white and blue Jubilee paint from 1977 gave way to blue and white in a £4 million refurbishment of 2008–2012. In 1982 the walkways reopened as part of the Tower Bridge Exhibition, along with the towers and the engine rooms.
Tower Bridge vs London Bridge: Two Crossings 800 Meters Apart
Visitors often call Tower Bridge "London Bridge." They are different structures about 800 m apart, and London Bridge is the plainer one.
| Tower Bridge | London Bridge | |
|---|---|---|
| Current structure opened | 1894 | 1973 |
| Type | Bascule and suspension, with towers | Prestressed concrete box-girder |
| Opens for ships? | Yes | No (fixed) |
| Position | Beside the Tower of London | Upstream, the historic City crossing |
A London Bridge has stood near the same spot since Roman times. The stone bridge by John Rennie, opened in 1831, was sinking and too narrow for traffic by the 1960s. In 1968 the City sold it to the American entrepreneur Robert P. McCulloch for $2,460,000. He had it taken apart, shipped the facing stones to Arizona and rebuilt them over a concrete core at Lake Havasu City, where it was rededicated in 1971. The story that McCulloch thought he was buying Tower Bridge is a legend. McCulloch denied it, and so did Ivan Luckin, the councillor who sold him the bridge. It lasts because tourists still make that mistake.
Crossing, Climbing and Catching a Lift in 2026
The roadway is free to cross on foot at any time. It carries the London Inner Ring Road and marks the eastern edge of the congestion charge zone, though crossing it does not incur the charge. To protect the structure there is a 20 mph limit and an 18-tonne weight limit, enforced by cameras. The nearest stations are Tower Hill on the District and Circle lines and Tower Gateway on the DLR to the north, and London Bridge to the southwest.
The Tower Bridge Exhibition is a paid attraction. You enter on the west side of the North Tower and go up to the walkways, which are now enclosed. Glass floor panels were added in 2014, so you can look straight down at buses and boats about 44 m below. Then you cross to the South Tower and follow a blue line to the engine rooms under the southern approach. In 2019 it drew 889,338 visitors. The bridge belongs to the City Bridge Foundation, a charity founded in 1282.
River traffic still has priority. Vessels with masts or superstructure over about 9 m must book a lift at least 24 hours ahead, and the crossing is free. Lift times are published online. Estimates of the annual total vary: the figure most often quoted is around 800 lifts a year, while some sources say nearer 1,000. Either way it is far fewer than the 6,160 of 1894–95. Sailing barges, cruise ships and naval vessels make most bookings.
The best views are from the south bank at Shad Thames and from Potters Fields Park. Walk west past HMS Belfast to London Bridge to see the difference. The Tower itself, which gave the bridge its name and its Gothic stonework, is covered in our guide to the Tower of London. The river the bridge was built to keep open is the subject of our complete guide to the Thames, and you can see how Barry's design compares with other great spans in this round-up of famous bridges around the world.