Tubular bridge

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Tubular bridge
Conwy Castle and Railway Bridge.jpg
Ancestor Plate girder bridge
Descendant Box girder bridge
Carries heavy rail
Span rangeMedium
Material Wrought iron
MovableNo
Design effortVery high
Falsework requiredDepends upon length and degree of prefabrication

A tubular bridge is a bridge built as a rigid box girder section within which the traffic is carried. [1] Famous examples include the original Britannia Bridge over the Menai Strait, the Conwy railway bridge over the River Conwy, designed and tested by William Fairbairn and built by Robert Stephenson between 1846 and 1850, and the original Victoria Bridge in Montreal.

Contents

Conwy and Britannia Bridges

Conwy Bridge.Construction of second tube, September, 1848 Conway Bridge. Construction of second tube, September, 1848.jpeg
Conwy Bridge.Construction of second tube, September, 1848

The Conwy railway bridge carries the North Wales coast railway line across the River Conwy between Llandudno Junction and the town of Conwy. [2] The wrought iron tubular bridge was built by Robert Stephenson to a design by William Fairbairn and is similar in construction to Stephenson's other famous tubular bridge, the Britannia Bridge across the Menai Strait. It was officially opened in 1849 but had been completed in 1848. Being the first tubular bridge to be built, the design needed much testing on prototypes to confirm that it would be capable of carrying heavy locomotives, the testing being performed by Fairbairn. The successful result enabled the much larger Britannia bridge to be built. The current Conwy bridge has been reinforced by extra columns under the bridge into the river but is otherwise virtually unchanged since it was built.

Before the Britannia Bridge was constructed, Fairbairn conducted "the most celebrated of all engineering experiments on the grand scale", [3] a series of experiments "of a gigantic character". [3] One-sixth scale models, 78 ft long, were built at Fairbairn's Millwall Iron Works and tested with increasing loads. By this means, although at an experimental cost of thousands of pounds, the design of the cellular girder was refined until it could carry loads of 2.4 times the original capacity. [3] The most significant finding was that of a thin section's susceptibility to buckling under compression loads and the cellular girder's resistance to this. Stephenson's would build around a thousand other bridges using this cellular structure. [3] The most impressive test was performed on-site at Conway. The 1300 ton tubular girder, deflecting 8 inches under its own weight, was loaded with a further 300 tons and the deflection measured. The effects of wind loading and asymmetric thermal expansion due to sunlight were also studied. [3]

Chepstow and Tamar Bridges

At Chepstow, a tubular railway bridge was built to the instructions of Isambard Kingdom Brunel in 1852. The "Great Tubular Bridge" over the River Wye, which at that point forms the boundary between Wales and England, is considered one of Brunel's major achievements, despite its appearance. It was economical in its use of materials, and would prove to be the design prototype for Brunel's Royal Albert Bridge at Saltash.

Other bridges

The unconventional nature of the tubular girder bridge was not widely accepted. John Fowler's 1847 tubular girder design for Torksey used tubes that were only 10 foot high and placed the railway deck between them, rather than inside. [4] This is now considered as the first box girder bridge, rather than a pure tubular bridge. [5] Despite this, it was initially rejected after completion by the Board of Trade’s inspector, Captain Lintorn Simmons, and the design was also criticized by the Institution of Civil Engineers. [6] [7] When the bridge was strengthened in 1897, this was done by added a central truss above the deck rather than by strengthening the box. [7]

Legacy

Section of the original wrought-iron tubular Britannia Bridge standing in front of the modern bridge Britannia Bridge wrought iron section.jpg
Section of the original wrought-iron tubular Britannia Bridge standing in front of the modern bridge
Original Britannia Bridge Britanniabruecke Postkarte coloriert2.jpg
Original Britannia Bridge

Since the destruction by fire of Britannia Bridge in 1970, Conwy railway bridge remains the only surviving example of this means of construction undertaken by Stephenson.

In the case of the Britannia Bridge this technology allowed a bridge with spans up to 460 feet (140 m) long to be constructed, when until then the longest wrought iron span had been 31 feet 6 inches (9.60 m).

See also

Related Research Articles

<span class="mw-page-title-main">Robert Stephenson</span> British civil engineer and locomotive designer (1803–1859)

Robert Stephenson, DCL was an English civil engineer and designer of locomotives. The only son of George Stephenson, the "Father of Railways", he built on the achievements of his father. Robert has been called the greatest engineer of the 19th century. Stephenson's death was widely mourned, and his funeral afforded marks of public honour. He is buried in Westminster Abbey.

<span class="mw-page-title-main">Royal Albert Bridge</span> Railway bridge spanning the River Tamar in southwest England

The Royal Albert Bridge is a railway bridge which spans the River Tamar in England between Plymouth, Devon and Saltash, Cornwall. Its unique design consists of two 455-foot (138.7 m) lenticular iron trusses 100 feet (30.5 m) above the water, with conventional plate-girder approach spans. This gives it a total length of 2,187.5 feet (666.8 m). It carries the Cornish Main Line railway in and out of Cornwall. It is adjacent to the Tamar Bridge which opened in 1961 to carry the A38 road.

<span class="mw-page-title-main">William Fairbairn</span> Scottish civil engineer and shipbuilder

Sir William Fairbairn, 1st Baronet of Ardwick was a Scottish civil engineer, structural engineer and shipbuilder. In 1854 he succeeded George Stephenson and Robert Stephenson to become the third president of the Institution of Mechanical Engineers.

<span class="mw-page-title-main">Britannia Bridge</span> Road-rail bridge over the Menai Strait

Britannia Bridge is a bridge in Wales that crosses the Menai Strait between the Isle of Anglesey and city of Bangor. It was originally designed and built by the noted railway engineer Robert Stephenson as a tubular bridge of wrought iron rectangular box-section spans for carrying rail traffic. Its importance was to form a critical link of the Chester and Holyhead Railway's route, enabling trains to directly travel between London and the port of Holyhead, thus facilitating a sea link to Dublin, Ireland.

<span class="mw-page-title-main">Conwy Railway Bridge</span> Bridge in Conwy, Wales

The Conwy Railway Bridge carries the North Wales coast railway line across the River Conwy between Llandudno Junction and the town of Conwy. The wrought iron tubular bridge, which is now Grade I listed, was built in the 19th century. It is the last surviving example of this type of design by Stephenson after the original Britannia Bridge across the Menai Strait was partially destroyed in a fire in 1970 and rebuilt as a two-tier truss arch bridge design.

<span class="mw-page-title-main">Torksey</span> Village in Lincolnshire, England

Torksey is a small village in the West Lindsey district of Lincolnshire, England. The population of the civil parish at the 2011 census was 875. It is situated on the A156 road, 7 miles (11 km) south of Gainsborough and 9 miles (14 km) north-west of Lincoln, and on the eastern bank of the tidal River Trent, which here forms the boundary with Nottinghamshire.

<span class="mw-page-title-main">Chepstow Railway Bridge</span> Bridge spanning the River Wye between England and Wales

Chepstow Railway Bridge was built to the instructions of Isambard Kingdom Brunel in 1852. The "Great Tubular Bridge" over the River Wye at Chepstow, which at that point forms the boundary between Wales and England, is considered one of Brunel's major achievements, despite its appearance. It was economical in its use of materials, and would prove to be the design prototype for Brunel's Royal Albert Bridge at Saltash. Although the superstructure has since been replaced, Brunel's tubular iron supports are still in place. It is a Grade II listed structure.

<span class="mw-page-title-main">Dee Bridge disaster</span> Railway accident

The Dee Bridge disaster was a rail accident that occurred on 24 May 1847 in Chester, England, that resulted in five fatalities. It revealed the weakness of cast iron beam bridges reinforced by wrought iron tie bars, and brought criticism of its designer, Robert Stephenson, the son of George Stephenson.

<span class="mw-page-title-main">Box girder</span> Type of girder

A box girder or tubular girder is a girder that forms an enclosed tube with multiple walls, as opposed to an Ɪ- or H-beam. Originally constructed of wrought iron joined by riveting, they are now made of rolled or welded steel, aluminium extrusions or prestressed concrete.

<span class="mw-page-title-main">Loughor Viaduct</span> Bridge over River Loughor, south Wales

The Loughor railway viaduct carries the West Wales Line across the River Loughor. It is adjacent, and runs parallel to, the Loughor road bridge. The 1880 viaduct was granted Grade II listed building status. Before it was demolished in early 2013, the viaduct was the last remaining timber viaduct designed by Isambard Kingdom Brunel.

<span class="mw-page-title-main">Saltwater River Rail Bridge</span> Bridge in Victoria, Australia

The Saltwater River Rail Bridge is a large steel arch truss railway bridge completed in 1858 and crossing the Maribyrnong River on the Melbourne to Footscray railway in Melbourne, Victoria. It had the longest span of any bridge in Victoria for thirty years.

<span class="mw-page-title-main">Usk Railway Bridge</span> Bridge in Newport

The Usk Railway Bridge is a railway viaduct in Newport city centre, Wales. It crosses the River Usk in an east—west direction, carrying the Great Western Main Line.

<span class="mw-page-title-main">Victoria Bridge, Penrith</span> Bridge in New South Wales, Australia

The Victoria Bridge, also known as the Victoria Bridge over the Nepean River, is a heritage-listed former railway bridge and now wrought iron box plate girder road bridge across the Nepean River on the Great Western Highway in the western Sydney suburb of Penrith in the City of Penrith local government area of New South Wales, Australia. The bridge was designed by John Whitton, the Engineer–in–Chief of New South Wales Government Railways, and built from 1862 to 1867 by William Piper, Peto Brassey and Betts (superstructure), William Watkins (piers). It is also known as Victoria Bridge, The Nepean Bridge and RTA Bridge No. 333. It was added to the New South Wales State Heritage Register on 27 May 2016.

<span class="mw-page-title-main">Windsor Railway Bridge</span> Bridge in Windsor

Windsor Railway Bridge is a wrought iron 'bow and string' bridge in Windsor, Berkshire, crossing the River Thames on the reach between Romney Lock and Boveney Lock. It carries the branch line between Slough and Windsor.

<span class="mw-page-title-main">Cathedral Bridge</span> Former road and rail bridge in Cologne, Germany

The Cathedral Bridge was a railway and street bridge crossing the river Rhine in the German city of Cologne. It was owned by the Cologne-Minden Railway Company and named after the Cologne Cathedral, which is located on the same longitudinal axis. It was built in combination with the original Central Station and a new ground-level railway track through the northern Old Town of the Cologne Innenstadt. As the Cathedral Bridge could not support the increased traffic of the new Köln Hauptbahnhof in 1894, it was replaced by the Hohenzollern Bridge in 1911.

<span class="mw-page-title-main">Gaunless Bridge</span> Bridge in County Durham, England

Gaunless Bridge was a railway bridge on the Stockton and Darlington Railway. It was completed in 1823 and is one of the first railway bridges to be constructed of iron and the first to use an iron truss. It is also of an unusual lenticular truss design.

<span class="mw-page-title-main">Nepean River railway bridge, Menangle</span> Bridge in New South Wales, Australia

The Nepean River railway bridge is a heritage-listed railway bridge that carries the Main Southern railway line across Menangle Road and the Nepean River located at the outer south-western Sydney settlement of Menangle in the Wollondilly Shire local government area of New South Wales, Australia. It was designed by John Whitton as the Engineer-in-Chief, of the New South Wales Government Railways and NSW Department of Public Works. The railway bridge was built in 1863 by Messers Peto, Brassey and Betts. It is also known as Menangle rail bridge over Nepean River and Menangle Railway Bridge. The property was added to the New South Wales State Heritage Register on 2 April 1999.

<span class="mw-page-title-main">Balloon flange girder</span>

A balloon flange girder is a form of vertical I-beam wrought iron plate girder, where the top flange, instead of being a simple flat plate, is extended into a hollow tube. When a girder is subjected to a positive bending moment the top flange acts in compression making a flat plate flange more susceptible to local buckling than the balloon flange is.

<span class="mw-page-title-main">Broadbottom Viaduct</span> Bridge in England, grid reference

Broadbottom Viaduct is a railway viaduct that spans the River Etherow between Derbyshire and Greater Manchester in England. Originally of wooden construction supported by stone piers, the timber was replaced first with wrought iron box girders, less than 20 years after the viaduct's opening, later followed by steel trusses and more supporting piers.

<span class="mw-page-title-main">Surtees Rail Bridge</span> Rail-bridge over the River Tees, Northern England

The Surtees Rail Bridge is a rail bridge on the Tees Valley Line over the River Tees in the Borough of Stockton-on-Tees. The bridge is south of Stockton-on-Tees town centre and just north of the adjacent Surtees Bridge which carries the A66 road. The bridge is built on the site of a series of Tees Bridges alternating between two adjacent crossing sites.

References

  1. Chrimes, Mike (1991). Civil Engineering 1839-1889. Alan Sutton Publishing. p. 47. ISBN   1-84015-008-4.
  2. Dreicer, Gregory K. (2010). "Building Bridges and Boundaries: The Lattice and the Tube, 1820-1860". Technology and Culture . 51 (1): 126–163. doi:10.1353/tech.0.0406. JSTOR   40646995.
  3. 1 2 3 4 5 Smith, A.I. (1966). William FairbairnExperimental Engineer. Engineering Heritage. Vol. II. Institution of Mechanical Engineers. pp. 22–23.
  4. Tatraskoda (27 February 2010). "John Fowler's Viaduct at Torksey". Flickr.
  5. "Torksey Bridge".
  6. Chrimes (1991), pp. 37–38.
  7. 1 2 "Torksey Viaduct". Forgotten Relics.

Bibliography