A through arch bridge , also known as a through-type arch bridge , is a bridge that is made from materials such as steel or reinforced concrete, in which the base of an arch structure is below the deck but the top rises above it. It can either be lower bearing or mid-bearing . Thus, the deck is within the arch, and cables or beams that are in tension suspend the central part of the deck from the arch.
72-600: Wearmouth Bridge is a through arch bridge across the River Wear in Sunderland, England . It is the final bridge over the river before its mouth with the North Sea . The original Wearmouth Bridge was designed by Thomas Paine and opened in 1796. In 1805 the bridge was repaired, and between 1857 and 1859 it was reconstructed by Robert Stephenson . To accommodate the growing volume of traffic, construction began on
144-401: A bridge as early as 1814, when convict and noted architect Francis Greenway reputedly proposed to Governor Lachlan Macquarie that a bridge be built from the northern to the southern shore of the harbour. In 1825, Greenway wrote a letter to the then " The Australian " newspaper stating that such a bridge would "give an idea of strength and magnificence that would reflect credit and glory on
216-400: A change of government at the 1904 NSW State election construction never began. A unique three-span bridge was proposed in 1922 by Ernest Stowe with connections at Balls Head , Millers Point , and Balmain with a memorial tower and hub on Goat Island . In 1914, John Bradfield was appointed Chief Engineer of Sydney Harbour Bridge and Metropolitan Railway Construction, and his work on
288-421: A design for a suspension bridge and won the second prize of £500. In 1902, when the outcome of the first competition became mired in controversy, Selfe won a second competition outright, with a design for a steel cantilever bridge . The selection board were unanimous, commenting that, "The structural lines are correct and in true proportion, and... the outline is graceful". However due to an economic downturn and
360-580: A flat roadway, but bridges in flatter country rise above their road approaches. A wide bridge may require an arch so tall as to become a significant obstacle and incline for the roadway. Small bridges can be hump-backed , but larger bridges such as the Old Bridge, Pontypridd may become so steep as to require steps, making their use for wheeled traffic difficult. Railways also find arched bridges difficult as they are even less tolerant of inclines. Where simple arched bridges are used for railways on flat terrain
432-407: A large pneumatic rivet gun . The largest of the rivets used weighed 3.5 kg (8 lb) and was 39.5 cm (15.6 in) long. The practice of riveting large steel structures, rather than welding, was, at the time, a proven and understood construction technique, whilst structural welding had not at that stage been adequately developed for use on the bridge. At each end of the arch stands
504-532: A large contemporary brass plaque being bolted very tightly to the side of one of the granite columns of the bridge to makes things clear. The official ceremony to mark the turning of the first sod occurred on 28 July 1923, on the spot at Milsons Point where two workshops to assist in building the bridge were to be constructed. An estimated 469 buildings on the north shore, both private homes and commercial operations, were demolished to allow construction to proceed, with little or no compensation being paid. Work on
576-523: A pair of 89-metre-high (292 ft) concrete pylons, faced with granite . The pylons were designed by the Scottish architect Thomas S. Tait , a partner in the architectural firm John Burnet & Partners. Some 250 Australian, Scottish, and Italian stonemasons and their families relocated to a temporary settlement at Moruya , 300 km (186 mi) south of Sydney, where they quarried around 18,000 m (635,664 cu ft) of granite for
648-513: A tunnel to complement the bridge. It was determined that the bridge could no longer support the increased traffic flow of the 1980s. The Sydney Harbour Tunnel was completed in August 1992 and carries only motor vehicles. The Bradfield Highway is designated as a Travelling Stock Route which means that it is permissible to herd livestock across the bridge, but only between midnight and dawn, and after giving notice of intention to do so. In practice,
720-480: Is 52,800 tonnes (52,000 long tons; 58,200 short tons), with the arch itself weighing 39,000 tonnes (38,000 long tons; 43,000 short tons). About 79% of the steel, specifically those technical sections constituting the curve of the arch, was imported pre-formed from England, with the rest being sourced from the Newcastle Steelworks . On site, Dorman Long & Co set up two workshops at Milsons Point, at
792-518: Is constructed in place or lifted into position. In some cases, this type of arch has been created by constructing cantilevers from each side, with the shoreside ends bolted securely down into heavy piers. The incomplete channel ends are then constructed toward each other and either filled by construction or by lifting a prefabricated center section. This type of construction was used in the Sydney Harbour Bridge illustrated above, with
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#1732772098159864-485: Is four each way. For the morning peak hour, the lane changes on the bridge also require changes to the Warringah Freeway , with its inner western reversible carriageway directing traffic to the bridge lane numbers three and four southbound. Until September 1982, during the evening peak the tidal flow was set as six northbound and two southbound lanes. The bridge has a series of overhead gantries which indicate
936-399: Is not practical to support the arch from beneath during construction. In modern construction, temporary towers are erected and supported by cables anchored in the ground. Temporary cables fly from each side to support arch segments as they are constructed. When the arches are almost complete a jacking bridge is placed over or beneath the gap to force the arches apart, whence the final section
1008-559: The Cahill Expressway , or the Western Distributor . Drivers on the northern side will find themselves on the Warringah Freeway , though it is easy to turn off the freeway to drive westwards into North Sydney or eastwards to Neutral Bay and beyond upon arrival on the northern side. The bridge originally only had four wider traffic lanes occupying the central space which now has six, as photos taken soon after
1080-975: The Chaotianmen Bridge in China, the world's longest through arch bridge; Tyne Bridge of Newcastle upon Tyne ; the Bayonne Bridge that connects New York City to New Jersey , which is longer than the Sydney Harbour Bridge; the Ahwaz White Bridge ; the Bourne Bridge and Sagamore Bridge , smaller, near-twin bridges over the Cape Cod Canal ; the Pennybacker Bridge in Austin , Texas and as
1152-676: The Hernando de Soto Bridge in Memphis, Tennessee . Wylam Railway Bridge is an early through arch bridge upstream of the Tyne Bridge. The through arch bridge usually consists of two ribs, although there are examples like the Hulme Arch Bridge of through arches with a single rib. When the two arches are built in parallel planes, the structure is a parallel rib arch bridge. When the two arch ribs lean together and shorten
1224-571: The Sydney Harbour Tunnel , with the base of the southern pylon containing the Transport for NSW maintenance shed for the bridge, and the base of the northern pylon containing the traffic management shed for tow trucks and safety vehicles used on the bridge. In 1942, the pylons were modified to include parapets and anti-aircraft guns designed to assist in both Australia's defence and general war effort. There had been plans to build
1296-567: The Duke of York (who would later become King George VI ). The cost of the bridge amounted to £231,943 of which £12,000 was spent on dismantling the old bridge. The adjoining Monkwearmouth Railway Bridge was built in 1879, and extended the railway south from Monkwearmouth to the centre of Sunderland. The bridge carries the A183 road between Chester-le-Street and South Shields and the A1018 which
1368-650: The NSW Department of Public Works prepared a general design for a single-arch bridge based upon New York City 's Hell Gate Bridge . In 1922 the government of George Fuller passed the Sydney Harbour Act 1922 , specifying the construction of a high-level cantilever or arch bridge across the Harbour between Dawes Point and Milsons Point, along with construction of necessary approaches and electric railway lines, and worldwide tenders were invited for
1440-456: The angled foundations built into their sides. Once work had progressed sufficiently on the support structures, a giant creeper crane was erected on each side of the harbour. These cranes were fitted with a cradle, and then used to hoist men and materials into position to allow for erection of the steelwork. To stabilise works while building the arches, tunnels were excavated on each shore with steel cables passed through them and then fixed to
1512-418: The arches, allowing the roadway and other parts of the bridge to be constructed from the centre out. The vertical hangers were attached to the arch, and these were then joined with horizontal crossbeams. The deck for the roadway and railway were built on top of the crossbeams, with the deck itself being completed by June 1931, and the creeper cranes were dismantled. Rails for trains and trams were laid, and road
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#17327720981591584-544: The associated roadway as the Bradfield Highway. After they did so, there was a 21-gun salute and an Royal Australian Air Force flypast . The intruder was identified as Francis de Groot . He was convicted of offensive behaviour and fined £5 after a psychiatric test proved he was sane, but this verdict was reversed on appeal. De Groot then successfully sued the Commissioner of Police for wrongful arrest and
1656-438: The base of the pylons are essential to support the loads from the arch and hold its span firmly in place, but the pylons themselves have no structural purpose. They were included to provide a frame for the arch panels and to give better visual balance to the bridge. The pylons were not part of the original design, and were only added to allay public concern about the structural integrity of the bridge. Although originally added to
1728-532: The bridge again built momentum. Bradfield persevered with the project, fleshing out the details of the specifications and financing for his cantilever bridge proposal, and in 1921 he travelled overseas to investigate tenders. His confidential secretary Kathleen M. Butler handled all the international correspondence during his absence, her title belying her role as project manager as well as a technical adviser. On return from his travels Bradfield decided that an arch design would also be suitable and he and officers of
1800-410: The bridge and its approaches, is named in honour of Bradfield's contribution to the bridge. Bradfield visited the site sporadically throughout the eight years it took Dorman Long to complete the bridge. Despite having originally championed a cantilever construction and the fact that his own arched general design was used in neither the tender process nor as input to the detailed design specification (and
1872-596: The bridge by symmetrical ramps and tunnels. The eastern-side railway tracks were intended for use by a planned rail link to the Northern Beaches ; in the interim they were used to carry trams from the North Shore into a terminal within Wynyard station, and when tram services were discontinued in 1958, they were converted into extra traffic lanes. The Bradfield Highway , which is the main roadway section of
1944-666: The bridge carries rail, vehicular, bicycle and pedestrian traffic. Under the direction of John Bradfield of the New South Wales Department of Public Works , the bridge was designed and built by British firm Dorman Long of Middlesbrough , and opened in 1932. The bridge's general design, which Bradfield tasked the NSW Department of Public Works with producing, was a rough copy of the Hell Gate Bridge in New York City . The design chosen from
2016-471: The bridge coincided with the construction of a system of underground railways beneath Sydney's CBD, known today as the City Circle , and the bridge was designed with this in mind. The bridge was designed to carry six lanes of road traffic, flanked on each side by two railway tracks and a footpath. Both sets of rail tracks were linked into the underground Wynyard railway station on the south (city) side of
2088-429: The bridge itself commenced with the construction of approaches and approach spans, and by September 1926 concrete piers to support the approach spans were in place on each side of the harbour. As construction of the approaches took place, work was also started on preparing the foundations required to support the enormous weight of the arch and loadings. Concrete and granite faced abutment towers were constructed, with
2160-426: The bridge pylons. The stonemasons cut, dressed, and numbered the blocks, which were then transported to Sydney on three ships built specifically for this purpose. The Moruya quarry was managed by John Gilmore, a Scottish stonemason who emigrated with his young family to Australia in 1924, at the request of the project managers. The concrete used was also Australian-made and supplied from Kandos . Abutments at
2232-438: The bridge solely for their aesthetic value, all four pylons have now been put to use. The south-eastern pylon contains a museum and tourist centre, with a 360° lookout at the top providing views across the Harbour and city. The south-western pylon is used by Transport for NSW to support its CCTV cameras overlooking the bridge and the roads around that area. The two pylons on the north shore include venting chimneys for fumes from
Wearmouth Bridge - Misplaced Pages Continue
2304-541: The bridge was AU£ 6.25 million, which was not paid off in full until 1988. The bridge was formally opened on Saturday, 19 March 1932. Among those who attended and gave speeches were the Governor of New South Wales , Sir Philip Game , and the Minister for Public Works, Lawrence Ennis . The Premier of New South Wales , Jack Lang , was to open the bridge by cutting a ribbon at its southern end. However, just as Lang
2376-526: The bridge was also used to cut the ribbon at the dedication of the Bayonne Bridge , which had opened between Bayonne, New Jersey , and New York City the year before. Despite the bridge opening in the midst of the Great Depression , opening celebrations were organised by the Citizens of Sydney Organising Committee, an influential body of prominent men and politicians that formed in 1931 under
2448-459: The bridge. One of three microphones used at the opening ceremony was signed by 10 local dignitaries who officiated at the event, Philip Game, John Lang, MA Davidson, Samuel Walder, D Clyne, H Primrose, Ben Howe, John Bradfield, Lawrence Ennis and Roland Kitson. It was supplied by Amalgamated Wireless Australasia , who organised the ceremony's broadcast and collected by Philip Geeves, the AWA announcer on
2520-403: The centre of the arch, to 57 m (187 ft) at the ends next to the pylons. The arch has a span of 504 m (1,654 ft), and its summit is 134 m (440 ft) above mean sea level; expansion of the steel structure on hot days can increase the height of the arch by 18 cm (7.1 in). The total weight of the steelwork of the bridge, including the arch and approach spans,
2592-469: The chairmanship of the lord mayor to oversee the festivities. The celebrations included an array of decorated floats , a procession of passenger ships sailing below the bridge, and a Venetian Carnival . A message from a primary school in Tottenham , 515 km (320 mi) away in rural New South Wales, arrived at the bridge on the day and was presented at the opening ceremony. It had been carried all
2664-472: The colony and the Mother Country". Nothing came of Greenway's suggestions, but the idea remained alive, and many further suggestions were made during the nineteenth century. In 1840, naval architect Robert Brindley proposed that a floating bridge be built. Engineer Peter Henderson produced one of the earliest known drawings of a bridge across the harbour around 1857. A suggestion for a truss bridge
2736-425: The cost of building long approach embankments may be considerable. Further issues are the foundations for the bridge. Arch bridges generate large side thrusts on their footings and so may require a solid bedrock foundation. Flattening the arch shape to avoid the humpback problem, such as for Brunel's Maidenhead bridge , increases this side thrust. It is often impossible to achieve a flat enough arch, simply owing to
2808-519: The current bridge in 1927. It was designed by Mott, Hay and Anderson and fabricated by the famous bridge building firm of Sir William Arrol & Co. at their Dalmarnock Ironworks in Glasgow (they also built the famous Forth Rail Bridge and the steel structure of Tower Bridge in London). The new bridge was built around the old one to allow the road to remain open. It was opened on 31 October 1929 by
2880-632: The day. The radio is now in the collection of the Powerhouse Museum . The bridge itself was regarded as a triumph over Depression times, earning the nickname "the Iron Lung ", as it kept many Depression-era workers employed. In 2010, the average daily traffic included 204 trains, 160,435 vehicles and 1650 bicycles. From the Sydney CBD side, motor vehicle access to the bridge is via Grosvenor Street , Clarence Street , Kent Street ,
2952-619: The deafness experienced by many of the workers in later years was blamed on the project. Henri Mallard between 1930 and 1932 produced hundreds of stills and film footage which reveal at close quarters the bravery of the workers in tough Depression-era conditions. Interviews were conducted between 1982-1989 with a variety of tradesmen who worked on the building of the bridge. Among the tradesmen interviewed were drillers, riveters, concrete packers, boilermakers, riggers, ironworkers, plasterers, stonemasons, an official photographer, sleepcutters, engineers and draughtsmen. The total financial cost of
Wearmouth Bridge - Misplaced Pages Continue
3024-405: The deck from the arch by tension rods, chains or cables and allow a gap in the arch, so the deck can pass through it. The first of these in particular cannot be achieved with masonry construction and requires wrought iron or steel. The use of a through arch does not change the proportions or size of the arch: a large span will still require a tall arch, although this can now reach any height above
3096-495: The deck without obstructing traffic. The arch may also reach downwards at its sides, to either reach strong foundations or to place the roadway at a convenient height for spanning a deep valley from a plateau above. The Tyne Bridge demonstrates both of these advantages. A well-known example of this type is the Sydney Harbour Bridge in Australia, which is based on the Hell Gate Bridge in New York City . Other bridges include
3168-491: The deliberate tension member that is the key to a tied-arch. Although visually similar, tied- and untied- through-arch bridges are quite distinct structurally and are unrelated in how they distribute their loads. In particular, cast iron bridges such as the Stanley Ferry Aqueduct may resemble tied-arch bridges, but as cast iron is weak in tension they are not structurally a tied arch. In some locations it
3240-484: The detailed design and erection process of the bridge. Architects for the contractors were from the British firm John Burnet & Partners of Glasgow , Scotland. Lawrence Ennis, of Dorman Long, served as Director of Construction and primary onsite supervisor throughout the entire build, alongside Edward Judge, Dorman Long's Chief Technical Engineer, who functioned as Consulting and Designing Engineer. The building of
3312-475: The direction of flow for each traffic lane. A green arrow pointing down to a traffic lane means the lane is open. A flashing red "X" indicates the lane is closing, but is not yet in use for traffic travelling in the other direction. A static red "X" means the lane is in use for oncoming traffic. This arrangement was introduced in January 1986, replacing a slow operation where lane markers were manually moved to mark
3384-408: The distance between the arches near the top, the span is a basket handle arch bridge. Many tied-arch bridges are also through-arch bridges. As well as tying the side-loads of the arch, the tension member is also at a convenient height to form the bridge deck, as for a through-arch. The converse is not true: through-arch bridges do not imply that they are tied-arch bridges, unless they also provide
3456-594: The eastern side of the bridge, whilst a dedicated path for bicycle use runs along the western side. Between the main roadway and the western bicycle path lies the North Shore railway line . The main roadway across the bridge is known as the Bradfield Highway and is about 2.4 km (1.5 mi) long, making it one of the shortest highways in Australia. The arch is composed of two 28-panel arch trusses; their heights vary from 18 m (59 ft) at
3528-555: The heavy loads expected. In 1924, Kathleen Butler travelled to London to set up the project office within those of Dorman, Long & Co., "attending the most difficult and technical questions and technical questions in regard to the contract, and dealing with a mass of correspondence". Bradfield and his staff were ultimately to oversee the bridge design and building process as it was executed by Dorman Long and Co, whose Consulting Engineer, Sir Ralph Freeman of Sir Douglas Fox and Partners , and his associate Georges Imbault, carried out
3600-554: The last time livestock crossed the bridge was in 1999 for the Gelbvieh Cattle Congress. The bridge is equipped for tidal flow operation , permitting the direction of traffic flow on the bridge to be altered to better suit the morning and evening peak hour traffic patterns. The bridge has eight lanes, numbered one to eight from west to east. Lanes three, four and five are reversible. One and two always flow north. Six, seven, and eight always flow south. The default
3672-403: The limitations of the foundations – particularly in flat country. Historically, such bridges often became viaducts of multiple small arches. With the availability of iron or concrete as structural materials, it became possible to construct a through arch bridge : a bridge where the deck does not have to be carried over the top of the arch. This requires a structure that can both support
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#17327720981593744-485: The opening clearly show. In 1958 tram services across the bridge were withdrawn and the tracks replaced by two extra road lanes; these lanes are now the leftmost southbound lanes on the bridge and are separated from the other six road lanes by a median strip . Lanes 7 and 8 now connect the bridge to the elevated Cahill Expressway that carries traffic to the Eastern Distributor . In 1988, work began to build
3816-445: The opening festivities, a phenomenal number given that the entire population of Sydney at the time was estimated to be 1,256,000. There had also been numerous preparatory arrangements. On 14 March 1932, three postage stamps were issued to commemorate the imminent opening of the bridge. Several songs were composed for the occasion. In the year of the opening, there was a steep rise in babies being named Archie and Bridget in honour of
3888-580: The project over many years earned him the legacy as the father of the bridge. Bradfield's preference at the time was for a cantilever bridge without piers, and in 1916 the NSW Legislative Assembly passed a bill for such a construction, however it did not proceed as the Legislative Council rejected the legislation on the basis that the money would be better spent on the war effort. Following World War I , plans to build
3960-600: The project. As a result of the tendering process, the government received twenty proposals from six companies; on 24 March 1924 the contract was awarded to Dorman Long & Co of Middlesbrough , England well known as the contractors who later built the similar Tyne Bridge in Newcastle Upon Tyne , for an arch bridge at a quoted price of AU£ 4,217,721 11s 10d. The arch design was cheaper than alternative cantilever and suspension bridge proposals, and also provided greater rigidity making it better suited for
4032-471: The site of the present day Luna Park , and fabricated the steel into the girders and other required parts. The bridge is held together by six million Australian-made hand-driven rivets supplied by the McPherson company of Melbourne, the last being driven through the deck on 21 January 1932. The rivets were heated red-hot and inserted into the plates; the headless end was immediately rounded over with
4104-646: The steelwork in the towers, while day labourers manually cleaned the granite with wire brushes. The last stone of the north-west pylon was set in place on 15 January 1932, and the timber towers used to support the cranes were removed. On 19 January 1932, the first test train, a steam locomotive, safely crossed the bridge. Load testing of the bridge took place in February 1932, with the four rail tracks being loaded with as many as 96 New South Wales Government Railways steam locomotives positioned end-to-end. The bridge underwent testing for three weeks, after which it
4176-573: The supporting cables to the higher side of the arches removed after completion. Sydney Harbour Bridge The Sydney Harbour Bridge is a steel through arch bridge in Sydney , New South Wales , Australia , spanning Sydney Harbour from the central business district (CBD) to the North Shore . The view of the bridge, the Harbour, and the nearby Sydney Opera House is widely regarded as an iconic image of Sydney, and of Australia itself. Nicknamed "The Coathanger" because of its arch-based design,
4248-487: The tender responses was original work created by Dorman Long, who leveraged some of the design from its own Tyne Bridge . It is the tenth-longest spanning-arch bridge in the world and the tallest steel arch bridge , measuring 134 m (440 ft) from top to water level. It was also the world's widest long-span bridge, at 48.8 m (160 ft) wide, until construction of the new Port Mann Bridge in Vancouver
4320-516: The test train of the previous day, and were discovered too late to be ejected. The construction worksheds were demolished after the bridge was completed, and the land that they were on is now occupied by Luna Park. The standards of industrial safety during construction were poor by today's standards. Sixteen workers died during construction, but surprisingly only two from falling off the bridge. Several more were injured from unsafe working practices undertaken whilst heating and inserting its rivets, and
4392-499: The two halves of the arch touched for the first time. Workers riveted both top and bottom sections of the arch together, and the arch became self-supporting, allowing the support cables to be removed. On 20 August 1930 the joining of the arches was celebrated by flying the flags of Australia and the United Kingdom from the jibs of the creeper cranes. Once the arch was completed, the creeper cranes were then worked back down
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#17327720981594464-410: The upper sections of each half-arch to stop them collapsing as they extended outwards. Arch construction itself began on 26 October 1928. The southern end of the bridge was worked on ahead of the northern end, to detect any errors and to help with alignment. The cranes would "creep" along the arches as they were constructed, eventually meeting up in the middle. In less than two years, on 19 August 1930,
4536-417: The way from Tottenham to the bridge by relays of school children, with the final relay being run by two children from the nearby Fort Street Boys' and Girls' schools . After the official ceremonies, the public was allowed to walk across the bridge on the deck, something that would not be repeated until the 50th anniversary celebrations. Estimates suggest that between 300,000 and one million people took part in
4608-420: Was about to cut the ribbon, a man in military uniform rode up on a horse, slashing the ribbon with his sword and opening the Sydney Harbour Bridge in the name of the people of New South Wales before the official ceremony began. He was promptly arrested. The ribbon was hurriedly retied and Lang performed the official opening ceremony and Game thereafter inaugurated the name of the bridge as Sydney Harbour Bridge and
4680-591: Was anyway a rough copy of the Devil's Gate bridge produced by the NSW Works Department), Bradfield subsequently attempted to claim personal credit for Dorman Long's design. This led to a bitter argument, with Dorman Long maintaining that instructing other people to produce a copy of an existing design in a document not subsequently used to specify the final construction did not constitute personal design input on Bradfield's part. This friction ultimately led to
4752-510: Was awarded an undisclosed out of court settlement. De Groot was a member of a right-wing paramilitary group called the New Guard , opposed to Lang's leftist policies and resentful of the fact that a member of the British royal family had not been asked to open the bridge. De Groot was not a member of the regular army but his uniform allowed him to blend in with the real cavalry. This incident
4824-480: Was completed in 2012. The southern end of the bridge is located at Dawes Point in The Rocks area, and the northern end at Milsons Point on the lower North Shore . There are six original lanes of road traffic through the main roadway, plus an additional two lanes of road traffic on its eastern side, using lanes that were formerly tram tracks . Adjacent to the road traffic, a path for pedestrian use runs along
4896-430: Was declared safe and ready to be opened. The first trial run of an electric train over the bridge was successfully completed on both lines 11 March 1932. On 19 March 1932, 632 people were the first fare-paying passengers to cross the bridge by rail, paying a premium of 10 s. for the privilege, but they were not the first members of the public to do so. That distinction fell to a pair of clergymen who inadvertently boarded
4968-508: Was made in 1879, and in 1880 a high-level bridge estimated at £850,000 was proposed. In 1900, the Lyne government committed to building a new Central railway station and organised a worldwide competition for the design and construction of a harbour bridge, overseen by Minister for Public Works Edward William O'Sullivan . G.E.W. Cruttwell , a London based engineer, was awarded the first prize of £1,000. Local engineer Norman Selfe submitted
5040-498: Was one of several involving Lang and the New Guard during that year. A similar ribbon-cutting ceremony on the bridge's northern side by North Sydney's mayor, Alderman Primrose, was carried out without incident. It was later discovered that Primrose was also a New Guard member but his role in and knowledge of the de Groot incident, if any, are unclear. The pair of golden scissors used in the ribbon cutting ceremonies on both sides of
5112-404: Was surfaced using concrete topped with asphalt. Power and telephone lines, and water, gas, and drainage pipes were also all added to the bridge in 1931. The pylons were built atop the abutment towers, with construction advancing rapidly from July 1931. Carpenters built wooden scaffolding , with concreters and masons then setting the masonry and pouring the concrete behind it. Gangers built
5184-594: Was the old route of the A19 until the bypass was built leading to the Tyne Tunnel . It is a Grade II listed building. Through arch bridge For a specific construction method, especially for masonry arches, the proportions of the arch remain similar no matter what the size: wider arches are thus required to be taller arches. For a semi-circular arch, the height is half of the span. Bridges across deep, narrow gorges can have their arch placed entirely beneath
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