Sir Joseph Bazalgette, chief engineer of the Metropolitan Board of Works, submitted several designs, including one with a gigantic parabolic steel arch from which was hung a high-level roadway. This design bore a close resemblance to the Austerlitz Viaduct which was built at about the same time across the River Seine in Paris. In the end, the competition was narrowed down to the technologically modern designs by Bazalgette and a design for a medieval-looking drawbridge by the City Corporation’s architect, Horace Jones. At first sight, it must surely have seemed that this would be a one-sided contest. The Industrial Revolution in Britain had seen engineers eclipse architects in the design of so many pioneering structures, such as railways, train sheds and bridges, throughout the country, and Bazalgette was by now the pre-eminent engineer, following his success in building London’s sewers and embanking the Thames. However, Jones did have one advantage, in that as chief City Architect he was asked by the committee to comment on Bazalgette’s designs. Despite this conflict of interests, his criticisms were probably fair, and the committee decided that none of Bazalgette’s proposals provided sufficient headroom for tall ships to pass through and, besides, the approach roads would have been too steep for horse-drawn vehicles. Consequently, Jones was selected to design the new Tower Bridge.
Horace Jones (1819–87)
Horace Jones was born in London. He became apprenticed to William Tite, the architect of the Royal Exchange, and when Jones set up his own practice in 1842, Tite remained a strong supporter of his often controversial work. Jones’s massive Cardiff Town Hall of 1854 was opened to a mixture of acclaim and criticism which presaged the conflicting reactions which were to greet the opening of Tower Bridge 40 years later. When the post of City Architect came up for election in 1868, Tite commended Jones’s application for his ‘diligent, earnest and attentive’ approach, while Sir John Carmichael, one of his clients, commended him for ‘completing his work with strict regard to the financial portion of the contract’. No doubt these qualities appealed to the City fathers who appointed him to the post. He proceeded to design many public and commercial buildings, including the massive Smithfield Market, which has been described as a ‘cathedral to meat’, and Billingsgate Fish Market, which fronts the north bank of the Thames 400 yards upstream of today’s Tower Bridge. Horace Jones became president of RIBA from 1882 to 1884 and was knighted in 1886.
Despite being trained in classical architecture, Jones had become a proponent of the Gothic revival style, as epitomised by the Houses of Parliament, designed by Sir Charles Barry and Augustus Pugin. This fitted in well with the City Corporation’s stated requirement of harmonising the appearance of the new bridge with the Norman architecture of the nearby Tower of London, the city’s most historic building. However, Jones had no experience of bridges, so he was asked to collaborate with the engineer John Wolfe Barry, who by an amazing stroke of fate was the son of Jones’s architectural mentor, Sir Charles Barry.
John Wolfe Barry (1836–1918)
John Wolfe Barry was the youngest of five brothers, one of whom was the eminent architect E.M. Barry. He was apprenticed to Sir John Hawkshaw, under whom he worked on Charing Cross and Cannon Street railway bridges. In 1867, he formed his own engineering firm and undertook a wide variety of successful projects. These included the Barry Docks in Cardiff, extensions to the District Underground line and two bridges over the Thames – Kew Road Bridge and Blackfriars Railway Bridge. His experience in laying towers in soft subsoil under water was to prove invaluable in the construction of Tower Bridge. Barry later became the president of the Institution of Civil Engineers and was knighted in 1897 after the completion of Tower Bridge. His obituary in the January 1918 edition of Engineering praised his ‘wide experience, sound judgement and untiring energy, which made him the leader of his profession in Great Britain’.
The collaboration between Jones and Barry proved fruitful. Jones’s original sketch of a bascule bridge had appealed to the Corporation because it solved the problem of allowing access to shipping while conforming to the Gothic architecture of the eleventh-century Tower of London. However, the method of raising the bascules using steam-powered hoisting machinery was impractical, and the arched structure of the central span inhibited raising of the bascules to their fullest extent, which would impede the passage of tall sailing ships. Barry made the necessary changes, and the design submitted to Parliament in 1884 closely resembles the bridge we see today.
After much discussion, a parliamentary Act was passed in August 1885 ‘to empower the Corporation of London to construct a bridge over the River Thames near the Tower of London, with approaches thereto’. The final design as we know it today provided for a low-level road bridge which can be raised at the centre, together with two high-level walkways. This combination allowed even the tallest ships to pass through while pedestrians could still cross over using the walkways, which were accessible via steps or lifts.
The design encompasses four towers. The taller central towers provide support for the walkways, which rise 120 feet above road level and allow headroom of 135 feet for ships to pass underneath at high tide. The shorter bank-side towers support the chains used to suspend the road platforms which span the river as far as the central towers. At the top of the central towers, the chains are joined by tie-rods, which are cunningly concealed in the wrought-iron parapets of the two footbridges. All four towers are of granite and Portland stone, designed in a Gothic Scottish-baronial style in order to harmonise with the architecture of the Tower of London. However, all is not what it seems. In fact, each of the towers is constructed of four octagonal steel columns behind the cladding of stone. As an engineer, Barry may have been worried by the requirement that the real nature of the bridge was disguised. However, he justified this by pointing out that iron and steel are best protected from corrosion by encasing them in masonry. In a lecture in 1894, he admitted that ‘some purists will say that the lamp of truth has been sadly neglected in this combination of materials’, but he hoped that ‘we may forget that the towers have skeletons as much concealed as that of the human body, of which we do not think when we contemplate examples of manly or feminine beauty’.58
Tower Bridge’s high-level footways
Construction of Tower Bridge started in 1886, and the Memorial Stone was laid by the Prince of Wales on 21 June. Commenting on the ceremony, the 26 July 1886 edition of The Graphic welcomed the bridge as a free gift to Londoners from the Bridge House Estates. It also attacked the vested interests which had so long opposed a new bridge here and opined that the bridge might never have been built if Parliament’s powers had not been augmented by the latest Reform Act. In a final prophetic comment, it suggested that before long a new bridge even further to the east would be needed as London by then began at Tilbury.
During the ceremony, Horace Jones was nearly killed by falling machinery, but he survived to receive a knighthood in August of that year. Sadly, he died of heart disease in 1887 and so never saw the completion of his most famous work. It was up to Barry to see the project through. He made a number of changes to the design of the bridge, including adding the shorter abutment towers which had not appeared in Jones’s original design. One highly significant change was also made to the appearance of the bridge. Jones had originally envisaged cladding the steel of the towers in red brick, but his assistant and successor George Stevenson insisted on using stone. It is fascinating to speculate what Tower Bridge would have looked like if Jones had survived longer.
The construction project provided an enormous challenge. J.E. Tuit, the chief engineer for Sir William Arrol & Co., commented:
how difficult a problem the crossing of a river may be when the banks on one side of that river are very low, the river full of shipping, and the vested interests in the wharves on each side very large.59
This was written in 1894, after the bridge was finally opened four years later than originally estimated. One major cause of the slippage was the insistence by the City Corporation, under pre
ssure from the wharfingers, that a width of 160 feet of clear water be maintained in the middle of the river throughout the project so that ships could pass unhindered. This had a major effect on the pace of construction of the foundations of the tall river-towers, as it meant that they could not be worked on simultaneously.
It was decided to build the foundations of each of the river-towers in 12 caissons sunk 21 feet into the river-bed. Each caisson was an open-ended box of wrought iron which was lowered from a wooden platform. Divers were first sent down to dig into the gravel and clay by hand so that the caissons sank inch by inch to an initial depth of eight feet. They worked in teams of four in nine-hour shifts. On average, they managed to lower a caisson eight inches per day into the river-bed. After this slow and dangerous process, the water could be pumped out of the caissons so that navvies could descend and dig out the space more efficiently until the bottom of the caisson had reached the required depth of 21 feet. Finally, the caissons could be filled with concrete to form the foundations of the river-towers.
The men who worked on this stage of the project, the divers and navvies, were almost a race apart from the rest of the population. Diving was a highly specialised and dangerous occupation in the nineteenth century, as indeed it is today, even with much safer modern equipment. The first satisfactory breathing device was invented in the 1820s by John Deane of Whitstable after he had rescued horses trapped in burning stables by using a helmet from an old suit of armour and connecting it to an air line and pump so that the farmer could feed him with air while he led the horses out of the smoke-filled stables. Later, a Prussian engineer, Augustus Siebe, improved the design to produce a combined helmet and diving suit which was the basis for all diving equipment until well into the twentieth century. Victorian divers formed an elite band whose skills were most frequently used for salvage work on sunken ships, and tended to live a life apart. They had a reputation for being able to out-drink even the navvies.
The name ‘navvy’ comes from the men who worked on the navigation canals at the end of the eighteenth century and was taken over by the workers who performed a similar role on the construction of the railways from the 1820s onwards. Many were Irish, but there were also Scottish and English as well as some foreign navvies. In the early days, they formed an anarchic group of labourers moving from place to place to work on the vast number of railways and bridges that covered the country. Thomas Carlyle wrote about this period of hectic construction: ‘All the world calculates on getting to heaven by steam. I have not on my travels seen anything uglier than the disorganised mass of labourers, sunk three-fold deeper in brutality by the three-fold wages they are getting.’ Certainly, they were relatively well paid, as the contractors had to give them an incentive to complete often dangerous tasks on time. However, they were notorious for wild drinking sprees after receiving their weekly wages and often lost at least a day’s paid work while recovering from the after-effects. By the 1860s, most of the great railway projects had finished and the remaining navvies, such as the men who were employed on digging the foundations for Tower Bridge, lived a less anarchic life.
The contractors selected to construct the various stages of the bridge were among Britain’s and the world’s most renowned and experienced at the time. The contractor for all the steel work was Sir William Arrol & Co., which was responsible for the structural steel columns supporting all four towers, as well as the lattice girders of the high-level walkways. As much as possible was prefabricated at Arrol’s Dalmarnock works near Glasgow. However, the installation of the massive steel frames and the riveting of the walkway girders required hundreds of men to work at increasingly high levels above the river. It says much for Arrol’s efficiency and concern for the welfare of his workers that not a single death occurred during this phase of the project. The especially dangerous work of fixing the walkways was done from a wooden platform attached underneath. This method had the additional safety benefit that it prevented any tools or construction material falling onto the ships passing below. Any damage caused to shipping would have had a disastrous effect on the project.
William Arrol (1839–1913)
Born in Paisley, Scotland, William Arrol received no formal education. He served his apprenticeship as a blacksmith before getting a job at Laidlaw’s engineering works in Glasgow, where he soon became foreman. In 1868, he started his first business as a boilermaker and in 1872 built the Dalmarnock Ironworks, also near Glasgow, which was to become the largest structural steelworks in the United Kingdom, employing 5,000 workers. He earned a reputation as a model employer with a special concern for quality of work and the safety of his workers. One of the first major projects he undertook was the construction of the new bridge over the River Tay after the disaster of the destruction of the first bridge on the stormy night of 28 December 1879. On that night, the 13 central spans had been blown down, taking with them a train and 75 passengers and crew, who all perished in the Firth of Tay in one of the greatest disasters that has ever happened to an engineering structure. The Court of Inquiry found that the bridge design and quality of construction were inadequate to withstand the storm-force winds that can occur in the area. These findings had a profound effect on the future of bridge design, as well as probably leading to the premature death of the designer, Thomas Bouch, who had just been knighted for the construction of the seemingly impressive bridge. Arrol is most famous for his next major project, the construction of the Forth Railway Bridge. One of the first bridges to be made of steel, this mighty structure, consisting of three immense cantilevers and connecting girder spans, stretches to a total length of 1.5 miles and is still one of the largest bridges of its kind in the world. For this achievement, Arrol received a knighthood, and he was the obvious choice for building the superstructure of Tower Bridge.
The raising of Tower Bridge’s bascules
Tower Bridge is probably best known for its impressive central drawbridge. Despite its distinctly medieval appearance, the drawbridge was built to be operated by the most advanced technology available in the nineteenth century – hydraulic power. Driven by steam pumping engines, the system was installed by Sir William Armstrong (1810–1900), the pioneer of hydraulic machinery, whose inventions were widely used for lifting equipment in docks, mines and railways and even for raising the curtains in London theatres. He later became famous as the manufacturer of the Armstrong breech-loading gun, and after his death the output of this weaponry from the amalgamated firm of Vickers Armstrong helped win the Second World War. The drawbridge itself consists of two 1,200-ton bascules which can be raised to their fullest extent of 80 degrees in an amazing 60 seconds, allowing a ship to pass through in five minutes, by which time the bascules can be lowered and road traffic resumed.
The bascules work on the see-saw principle (bascule is the French word for see-saw). Each bascule is counterbalanced by a semicircular-shaped iron-and-lead weight of 422 tons, which is housed in a cavernous chamber in the top of the supporting piers of each of the river-towers, together with the machinery to raise the bascule. It is an awesome experience to stand at the bottom of this chamber and look up at the massive structure of the bascule and its counterweight towering above and ready to descend if the bridge is to be raised.
The operation of the bascules
As was common with major construction projects in those times, Tower Bridge was not completed without loss of life. According to the resident engineer, George Crutwell, four men died during the dangerous task of laying the foundations deep in the river. In addition, one man died during the construction of the approach roads and five working on the superstructure, making a total of ten. Barry himself records only six deaths. There were no health and safety regulations at the time, no safety harnesses, and the workmen wore soft caps rather than the hard hats required on today’s building sites. For an 8-year project with an average of 432 men employed throughout, it is certainly remarkable that there were so few fatalities. This compares with 57 fatalities during the much large
r Forth Bridge project, which William Arrol had worked on just prior to Tower Bridge.
Tower Bridge was finally opened on 30 June 1894 by the Prince of Wales. Massive crowds lined both sides of the Thames, and as many as could watched from boats as the royal party approached. The Times recorded the most dramatic moment of all:
The Prince turned the lever of the valve communicating with the hydraulic machinery and straightaway the two ponderous leaves, each 115 ft long, began as if by magic to rear themselves into the air. Forthwith the blare of trumpets was drowned in the wild whistling of the steamers and in the shouts of the people without. Few sights more imposing and majestic have ever been seen in this country than the silent irresistible upheaval of these solid leaves of the bridge which fascinated the spectators on land and water.
The project had taken four years longer than originally planned and the total cost was nearly £1,200,000, compared with Barry’s original estimate of £750,000. Press comments at the time were by no means all favourable. Some thought the extra expense of providing a see-saw bridge was unnecessary and others complained about the use of stone to disguise the real nature of the structure. However, the public soon took it to their hearts, and, according to Honor Godfrey, a visiting Frenchman was highly complimentary about the bridge and, perhaps more surprisingly, about the English national character it seemed to exemplify.60
Crossing the River: The History of London's Thames River Bridges From Richmond to the Tower Page 27
