Cast iron has been produced in China since the 5th century BC, but was only introduced into Europe in the 15th century. Especially important in the production of canons and military equipment, production increased rapidly, often under royal patronage. In England major sites for military production and advances in metallurgical technology included the Woolwich Arsenal in London and the Royal Dockyards in Portsmouth. Although driven by the growing demands of Britain's military might, the technology of cast iron production and its uses spread into the civilian sphere, where advances in furnace technology continued to increase output significantly.
However, it wasn't until the 18th century that cast iron became available in quantities sufficient enough for its use in civil engineering construction. The breakthrough came in 1781, with the opening of the cast iron bridge spanning the river Severn at Ironbridge in Shropshire. Once the utility of this new material became accepted, it was used widely for bridge construction, especially on the already established canal system and later within the up and coming railways.
The use of cast iron for bridge construction was however relatively short lived, and after the Tay Rail Bridge disaster (1879) and the Norwood Junction rail accident (1891) its use rapidly declined. It became apparent that although very strong in compression, cast iron could be brittle and weak under tension, and this could lead to catastrophic failure of cast iron bridges under certain loading conditions (an obvious problem when running heavy railway engines and loaded carriages over them!).
Although virtually completely replaced on the railway network, cast iron bridges are still seen spanning canals and in aqueducts, where the loading conditions suit cast iron's physical properties.
Iron Bridges on the Oxford Canal
Just as lift bridges are associated with the southern part of the Oxford Canal, so cast iron bridges are more typical of its northern stretches.
There are twelve iron bridges and one iron aqueduct on the canal, all but two of which are made from cast iron, the remaining two being constructed of steel (an iron and carbon alloy). All of the cast iron structures have listed building status (Grade II) and the majority are on the northern (7) or mid (2) sections of the canal as against only 2 on the southern section.
Because cast iron only became available for widespread bridge building after the 1780's, the cast iron bridges we see on the Oxford canal do not represent those built during the original building phase. In fact, the cast bridges bridges of the northern canal were all built during the substantial improvements and straightening of the 1830's, and those of the middle and southern sections were probably built during a similar or slightly later period (see later discussion).
The Iron Bridges on the Oxford Canal:
However, it wasn't until the 18th century that cast iron became available in quantities sufficient enough for its use in civil engineering construction. The breakthrough came in 1781, with the opening of the cast iron bridge spanning the river Severn at Ironbridge in Shropshire. Once the utility of this new material became accepted, it was used widely for bridge construction, especially on the already established canal system and later within the up and coming railways.
The use of cast iron for bridge construction was however relatively short lived, and after the Tay Rail Bridge disaster (1879) and the Norwood Junction rail accident (1891) its use rapidly declined. It became apparent that although very strong in compression, cast iron could be brittle and weak under tension, and this could lead to catastrophic failure of cast iron bridges under certain loading conditions (an obvious problem when running heavy railway engines and loaded carriages over them!).
Although virtually completely replaced on the railway network, cast iron bridges are still seen spanning canals and in aqueducts, where the loading conditions suit cast iron's physical properties.
Iron Bridges on the Oxford Canal
Just as lift bridges are associated with the southern part of the Oxford Canal, so cast iron bridges are more typical of its northern stretches.
There are twelve iron bridges and one iron aqueduct on the canal, all but two of which are made from cast iron, the remaining two being constructed of steel (an iron and carbon alloy). All of the cast iron structures have listed building status (Grade II) and the majority are on the northern (7) or mid (2) sections of the canal as against only 2 on the southern section.
Because cast iron only became available for widespread bridge building after the 1780's, the cast iron bridges we see on the Oxford canal do not represent those built during the original building phase. In fact, the cast bridges bridges of the northern canal were all built during the substantial improvements and straightening of the 1830's, and those of the middle and southern sections were probably built during a similar or slightly later period (see later discussion).
The Iron Bridges on the Oxford Canal:
Bridge Number |
Name |
Location |
Carrying |
Construction Material (Span) |
Date Built |
243 |
Isis Lock Bridge |
Oxford |
Towpath over canal |
Cast Iron |
1790 (given) 1844 (likely)* |
217 |
Horse Bridge |
Shipton on Cherwell |
Towpath over river |
Steel |
1909 |
137A |
Fenny Compton Turnover Bridge |
Fenny Compton "Tunnel" |
Towpath over canal |
Cast Iron |
1840's |
105 |
Dunks Footbridge |
Lower Shuckburgh |
Path over canal |
Steel |
1934 |
94 |
Braunston Junction Bridge |
Braunston |
Towpath over canal |
Cast Iron |
c.1830 |
93 |
Braunston Junction Bridge |
Braunston |
Towpath over canal |
Cast Iron |
c.1830 |
54 |
Old Leicester Road Aqueduct |
Brownsover (Rugby) |
Canal over road |
Cast Iron |
1831-4 |
53 |
Rugby Wharf Arm Bridge |
Brownsover (Rugby) |
Towpath over canal arm |
Cast Iron |
1831-4 |
45 |
Newbold Loop Bridge |
Newbold (Rugby) |
Towpath over disused loop |
Cast Iron |
1831-4 |
39 |
Fennis Field Arm Bridge |
Cathiron (Rugby) |
Towpath over disused loop |
Cast Iron |
1831-4 |
32 |
Brinklow Arm Bridge |
Brinklow |
Towpath over disused arm |
Cast Iron |
1831-4 |
2 |
Hawkesbury Roving Bridge |
Hawkesbury (Coventry) |
Towpath over canal |
Cast Iron |
1837 |
1 |
Hawkesbury Junction Bridge |
Hawkesbury (Coventry) |
Towpath over canal |
Cast Iron |
1837 |
* See later for a discussion about the dating of bridge 243
The Northern Bridges (1 - 94)
These represent the vast majority of the iron bridges on the Oxford canal and fall into two groups:
- The Cubitt period bridges built during the modernisation and straightening of the canal between Hawkesbury and Braunston (1830-4)
- The two bridges built during the reconfiguration of the junction of the Oxford and Coventry canals at Hawkesbury (1837)
The Cubitt Period Bridges
The modernisation and shortening of the canal between Hawkesbury and Braunston was instigated by the economic challenge of the new Grand Junction Canal which connected the Midlands directly to London. This threatened the lucrative trade in the carriage of coal and manufactured goods on the "Oxford" and necessitated an immediate response.
When originally built, the Oxford Canal followed a tortuous route following the lands contours; this reduced construction costs with fewer locks, embankments and cuttings needed, but at the cost of longer journey times. Now, to remain competitive, this problem had to be addressed.
The answer was to drive a more direct route across country, and to overcome the challenges of the terrain with a series of technically demanding engineering undertakings. A new route was surveyed by Sir Marc Brunel and Charles Vignoles and William Cubitt was appointed as supervising engineer.
A series of embankments and aqueducts around Rugby and Brinklow, and the doubling of the locks at Hillmorton resulted in the straightening of the most circuitous portions of the canal and a reduction in its length by eleven and a half miles. This produced a number of redundant canal loops, many of which were retained to serve the lucrative trade to local wharves. These canal "arms" connected into the main canal at minor junctions and required bridging to allow the towpath to continue without interruption.
Two Surveyors and an Engineer: The Men Who Improved The Oxford Canal
Sir Marc Brunel (1769-1849)
A French citizen by birth, Brunel came from an affluent family of royalist sympathisers. During the French Revolution, he was forced to flee France and travelled to the USA (1793) where he was subsequently appointed as the chief engineer of New York City (1796).
Having devised an automated process for the production of pulley blocks for naval rigging (the Royal Navy alone needed 100,000 per year) he moved to London (1799) and married Sophia Kingdom, whom he had known since living in France. Together they had three children, two daughters and most famously a son, Isambard Kingdom Brunel, who exceeded even his fathers achievements. Marc successfully installed his pulley block manufacturing process in Portsmouth Dockyard, and went on to develop a wide range of automated manufacturing processes. As a civil engineer he was instrumental in the completion of the first tunnel under the Thames in London (opened 1842) and numerous other projects including those on the Oxford Canal. His greatest legacies to engineering include the development of the tunnelling shield and his son whose engineering feats became part of our cultural history.
A French citizen by birth, Brunel came from an affluent family of royalist sympathisers. During the French Revolution, he was forced to flee France and travelled to the USA (1793) where he was subsequently appointed as the chief engineer of New York City (1796).
Having devised an automated process for the production of pulley blocks for naval rigging (the Royal Navy alone needed 100,000 per year) he moved to London (1799) and married Sophia Kingdom, whom he had known since living in France. Together they had three children, two daughters and most famously a son, Isambard Kingdom Brunel, who exceeded even his fathers achievements. Marc successfully installed his pulley block manufacturing process in Portsmouth Dockyard, and went on to develop a wide range of automated manufacturing processes. As a civil engineer he was instrumental in the completion of the first tunnel under the Thames in London (opened 1842) and numerous other projects including those on the Oxford Canal. His greatest legacies to engineering include the development of the tunnelling shield and his son whose engineering feats became part of our cultural history.
Charles Blacker Vignoles (1793-1875)
Orphaned at just over a year old, Charles was raised by his grandfather, the eminent mathematician, Professor Charles Hutton. Turning his back on the law as a profession, and after a brief spell in the army, he sailed to the USA where he trained as a civil engineer and surveyor and became City Surveyor of St. Augustine, Florida in 1821. On the death of his grandfather in 1823 he returned to Britain and opened an engineering office in Hatton Garden, quickly establishing a reputation in the growing railway building craze. He collaborated with Brunel on the Oxford Canal straightening and the Thames Tunnel project, although ultimately the two fell-out over the later.
He continued to have a long and distinguished career in railway engineering, not only in Britain, but across continental Europe and in South America.
Orphaned at just over a year old, Charles was raised by his grandfather, the eminent mathematician, Professor Charles Hutton. Turning his back on the law as a profession, and after a brief spell in the army, he sailed to the USA where he trained as a civil engineer and surveyor and became City Surveyor of St. Augustine, Florida in 1821. On the death of his grandfather in 1823 he returned to Britain and opened an engineering office in Hatton Garden, quickly establishing a reputation in the growing railway building craze. He collaborated with Brunel on the Oxford Canal straightening and the Thames Tunnel project, although ultimately the two fell-out over the later.
He continued to have a long and distinguished career in railway engineering, not only in Britain, but across continental Europe and in South America.
Sir William Cubitt (1785-1861)
Born in Norfolk, the son of a miller, William showed an early ability in mechanics and worked for an agricultural machine maker. At the age of 22 he invented and patented a system of self regulating windmill sails and then moved to Ipswich where he worked for Ransome's Engineering and was appointed chief engineer.
In 1826 he moved to London and quickly established himself as a civil engineer. During this period he oversaw the improvements of the northern Oxford Canal and was involved with the building of the Liverpool Junction Canal. He also undertook important works on the Regents Canal in London and the Bute Docks in Cardiff.
Like his contemporaries, he was much in demand during the rapid development of the railways and acted as engineer-in-chief for the South Eastern Railway, overseeing the construction of the line between Folkestone and Dover.
He worked on a number of major projects across continental Europe and was knighted by Queen Victoria in 1851 for his work with the Great Exhibition.
Born in Norfolk, the son of a miller, William showed an early ability in mechanics and worked for an agricultural machine maker. At the age of 22 he invented and patented a system of self regulating windmill sails and then moved to Ipswich where he worked for Ransome's Engineering and was appointed chief engineer.
In 1826 he moved to London and quickly established himself as a civil engineer. During this period he oversaw the improvements of the northern Oxford Canal and was involved with the building of the Liverpool Junction Canal. He also undertook important works on the Regents Canal in London and the Bute Docks in Cardiff.
Like his contemporaries, he was much in demand during the rapid development of the railways and acted as engineer-in-chief for the South Eastern Railway, overseeing the construction of the line between Folkestone and Dover.
He worked on a number of major projects across continental Europe and was knighted by Queen Victoria in 1851 for his work with the Great Exhibition.
The cast iron bridges built during the improvements are considered to be amongst the most elegant examples of early cast iron bridge work. Their simple curves belie their engineering sophistication and their appearance set the standards by which subsequent cast iron bridges were judged.
Bridge 32 crossing the Brinklow Arm is a typical example:
Bridge 32 crossing the Brinklow Arm is a typical example:
This is the most northerly of the Cubitt period cast iron bridges (1831-34).
The graceful elliptical arch spans the junction of the Brinklow arm with the main Oxford Canal. The span is constructed of cast iron components joined centrally with a cast open parapet and top rail. The cambered deck is made from prefabricated cast iron plates.
This form of bridge is an early form of "flat-pack" construction; all of the major components being made off site, and bolted together to produce the finished article. The approach ramps and walling, built with blue Staffordshire bricks and shaped brick coping, continue the sinuous lines of the bridge.
As with almost all other Horseley Iron Works products, the name of the company is proudly displayed on the side of the bridge as part of the original casting process. During the Victorian era, the importance of advertising and product promotion began to be appreciated, even in the field of civil engineering!
This new concept of corporate branding (promoting the company rather than the specific product) was just beginning to appear, something that today we take for granted.
The remaining five bridges in this series, are virtually identical in appearance.
Braunston Junction Bridges (93 & 94)
Photo © Stephen McKay (cc-by-sa/2.0).
The junction between the Oxford Canal (to the left towards Coventry) and the Grand Junction Canal (to the right towards London) as seen from the the shared Oxford/Grand Union section. The elegant sweep of the cast iron bridges mirror one another and are linked by a brick bridge with similar proportions and elliptical arch. The flat top line and string course of the central bridge are typical of the brick bridges of the period.
The remaining structure in this group is the cast iron aqueduct crossing the Old Leicester Road in Rugby (Bridge 54). Much of the canal around Rugby was realigned during Cubitt's modernisation program which resulted in a number of cuttings and embankments with a series of aqueducts, of which this is the only one with a cast iron section.
The cast iron trough and supporting arch work has a functional appearance far removed from the elegant lines of the Horseley bridges. It is more akin to the Hawkesbury junction bridges, but no attribution as to manufacturer can be made. The iron work sits within a typical robust Victorian brick structure with square top line, vertical pilasters but attractively sweeping wing walls.
The Hawkesbury Junction Bridges
The junction at Hawkesbury between the Oxford and Coventry canals had always been a bone of contention between the two canal companies. Initially the two canals ran parallel for one mile before joining, but when a new junction at Hawkesbury was built it was found that the canals, which were supposed to be at the same level, differed in height by several inches. This necessitated the building of a lock between them, but still resulted in a continuous loss of water from the Oxford to the Coventry.
Improvements to the junction (1837), shortly after the Cubitt straightening further along the canal, included the building of two cast iron bridges.
Hawkesbury Junction Bridge is a cast iron construction spanning the junction between the Oxford and Coventry canals and providing continuity of the towpath along the latter. This bridge was built by the Britannia Foundry in Derby and the supervising engineer was J Sinclair of the Coventry Canal Company. Just like the Horseley bridges, the major iron components were made off-site and assembled onto the pre-prepared abutments.
The junction at Hawkesbury between the Oxford and Coventry canals had always been a bone of contention between the two canal companies. Initially the two canals ran parallel for one mile before joining, but when a new junction at Hawkesbury was built it was found that the canals, which were supposed to be at the same level, differed in height by several inches. This necessitated the building of a lock between them, but still resulted in a continuous loss of water from the Oxford to the Coventry.
Improvements to the junction (1837), shortly after the Cubitt straightening further along the canal, included the building of two cast iron bridges.
Hawkesbury Junction Bridge is a cast iron construction spanning the junction between the Oxford and Coventry canals and providing continuity of the towpath along the latter. This bridge was built by the Britannia Foundry in Derby and the supervising engineer was J Sinclair of the Coventry Canal Company. Just like the Horseley bridges, the major iron components were made off-site and assembled onto the pre-prepared abutments.
Hawkesbury Junction Bridge
Having an elliptical arch, the underlying engineering of this bridge is similar to the Horseley bridges, but the top line and x-framed openwork parapet fails to match their sinuous elegance.
Sutton Stop Roving Bridge
Just north of the junction, on the Oxford Canal, a roving bridge crosses at the lock. This bridge allowed the horses to cross over the canal and continue along the Coventry if needed.
A cast iron flat segmental arch with X-framed openwork parapet, this is very much a utilitarian bridge compared to the elegance of the Horseley and Britannia bridges. The approach walls are of red brick in English bond with rounded blue brick coping.
Just north of the junction, on the Oxford Canal, a roving bridge crosses at the lock. This bridge allowed the horses to cross over the canal and continue along the Coventry if needed.
A cast iron flat segmental arch with X-framed openwork parapet, this is very much a utilitarian bridge compared to the elegance of the Horseley and Britannia bridges. The approach walls are of red brick in English bond with rounded blue brick coping.
Sutton Stop (Hawkesbury Stop Lock) Roving Bridge
This bridge allows the horses to cross the canal and continue to the Coventry Canal.
The flat arch frame is of cast iron supporting a wooden plank decking.
The Northern Cast Iron Bridges: A Tale of Two Iron Manufacturing Empires
The building of the Oxford Canal and its subsequent improvements by Cubitt roughly coincides with the rapid expansion of manufacturing industries in Britain known as the Industrial Revolution (Hobsbawn gives dates of 1780 to 1840 and Ashton 1760 to 1830 for the Industrial Revolution). During this period many aspects of manufacturing expanded rapidly and became increasingly mechanised; changing Britain from a predominantly agricultural and rural economy to an ever increasing industrial and urban one. Britain was rapidly becoming "the workshop of the world".
Of particular interest to us are two iron producing companies; the Horseley Iron Works and the Britannia Foundry of Derby.
The Horseley Iron Works
Founded by Aaron Manby in 1815, the Horseley Iron Works were sited on the newly built Birmingham Canal on what had been part of the Horseley estate in Tipton, Staffordshire. The company rapidly gained a name for innovative and high quality cast iron production and made its reputation with the construction of the first iron steamer, The Aaron Manby, in 1821.
With the rapid expansion in canal building, the company began to specialise in the large iron castings needed for canal bridges and developed the process of "knock-down" construction; producing standardised parts in the foundry that were assembled on site.
The building of the Oxford Canal and its subsequent improvements by Cubitt roughly coincides with the rapid expansion of manufacturing industries in Britain known as the Industrial Revolution (Hobsbawn gives dates of 1780 to 1840 and Ashton 1760 to 1830 for the Industrial Revolution). During this period many aspects of manufacturing expanded rapidly and became increasingly mechanised; changing Britain from a predominantly agricultural and rural economy to an ever increasing industrial and urban one. Britain was rapidly becoming "the workshop of the world".
Of particular interest to us are two iron producing companies; the Horseley Iron Works and the Britannia Foundry of Derby.
The Horseley Iron Works
Founded by Aaron Manby in 1815, the Horseley Iron Works were sited on the newly built Birmingham Canal on what had been part of the Horseley estate in Tipton, Staffordshire. The company rapidly gained a name for innovative and high quality cast iron production and made its reputation with the construction of the first iron steamer, The Aaron Manby, in 1821.
With the rapid expansion in canal building, the company began to specialise in the large iron castings needed for canal bridges and developed the process of "knock-down" construction; producing standardised parts in the foundry that were assembled on site.
By the end of the canal building era, the Horseley company had emerged as one of the most prolific manufacturers of canal bridges in the West Midlands (especially in Birmingham).
Alongside canal bridge construction, the company also produced bridges and viaducts for the expanding railway network, as well as railway locomotives. It also produced structural parts for piers, theatres and railway stations; in later year it diversified into using other construction materials. Probably its last major public work was the Dome of Discovery for the Festival of Britain in 1951. |
Right: Festival of Britain 1951 On the south bank of the Thames in London, the vertical Skylon on the left and The Dome of Discovery on the right. At the time, at 111 m. in diameter, this was the largest dome in the world and was to prove to be one of the last major projects undertaken by the Horseley Iron Works. |
The company continued under a succession of owners until 1991 when it closed. The site, like so many sites of Victorian industrial innovation was redeveloped for housing.
The Britannia Foundry of Derby
Beginning life as Weatherhead, Glover and Co. in 1818, but trading under the name The Britannia Foundry of Derby, the company produced high quality cast iron ornamental urns, temples and window frames for churches and chapels. Taken over by Marshall, Baker and Wright in 1835 it expanded into producing large scale iron castings including those for canal bridges. After 1840 it became heavily involved with work for the railways (especially important given Derby's pivotal position within the railway network).
The Britannia Foundry of Derby
Beginning life as Weatherhead, Glover and Co. in 1818, but trading under the name The Britannia Foundry of Derby, the company produced high quality cast iron ornamental urns, temples and window frames for churches and chapels. Taken over by Marshall, Baker and Wright in 1835 it expanded into producing large scale iron castings including those for canal bridges. After 1840 it became heavily involved with work for the railways (especially important given Derby's pivotal position within the railway network).
In 1848 the company was bought by Andrew Handyside who continued to expand the diversity of products and production methods. Specialising in producing structural ironwork, exports increased substantially with Britannia Foundry bridges being supplied to the growing railway systems in India, Australia, South America and Japan.
|
Perhaps the most familiar, but most overlooked of the Britannia Foundry/Handyside products is the humble street postbox (pillar box). The first Handyside postboxes were produced in 1853, but in 1879, a contract with the post office gave the company dominance in the provision of these ubiquitous structures. Right : Typical Handyside late Victorian postbox (1889-1901 type),covered market, Oxford. |
Handyside died in 1887 and the company went into a long period of decline before final closure in the early 20th century.
Like its rival in Tipton, the foundry site in Derby ended its days as a housing estate, its memory preserved in a road name, Handyside Street and The Furnace public house.
Like its rival in Tipton, the foundry site in Derby ended its days as a housing estate, its memory preserved in a road name, Handyside Street and The Furnace public house.
The Southern Bridges (105 - 343)
From north to south these are:
Dunks Footbridge (105), Lower Shuckburgh, Warwickshire
This is a small footbridge carrying a footpath that connects Grandborough to the north with Lower Shuckburgh to the south. Typical of such footbridges, it was built to provide continuity of a rural right of way which is likely to have existed for several hundred years prior to the arrival of the canal.
Dunks Footbridge (105)
Built in 1934 to replace a previous crossing at this point, this is a high level footbridge approached by steps at either end.
The span consists of two I-shaped steel girders supporting a concrete deck. Parapet and side railing of steel angle iron and flat bar steel with square profile top hand rail.
The end abutments are of red brick laid in English Bond with prominent stone quoins at all corners.
Fenny Compton Turnover Bridge (137A), Fenny Compton "Tunnel", Warwickshire
A 19th century cast iron bridge that takes the towpath from one side of the canal to the other.
This stretch of the canal was originally carried underground in the 1,138 yard long Fenny Compton Tunnel. Constructed during the initial canal building phase (1776-78), the tunnel had always been a bottle-neck for the passage of narrow-boats, with only a few passing places along its length. In 1838 the land above the tunnel was purchased and work began to unroof and widen the canal. Initially the central section and lengths at either end were opened out, leaving two separate but shorter tunnels. Although better than before, this situation was still a hindrance to the free flow of craft, and in 1865 it was decided to unroof the whole length of the tunnel. During 1865-70 the work to unroof the whole tunnel was undertaken, leaving the widened canal in a deep, straight cutting, but still known as "the tunnel".
This unroofing meant that several new bridges had to be constructed to cross the now exposed canal, one of these is the Turnover bridge (137A).
Fenny Compton Turnover Bridge (137A)
Each face of the bridge is a single casting forming the arch, openwork balustrade and oval profile top rail. The underside of the arch (soffit) and footway decking are of cast iron plates.
Fenny Compton Turnover Bridge (137A)
The cast iron bridge-work is set on red brick abutments and sloping approach ramps with blue brick coping. Some modern rebuilding of the brickwork is apparent.
The overall impression is a bridge with a "lighter" appearance than its predecessors, but perhaps lacking the flowing lines of the Horseley bridges.
Note the dead straight line of the canal; a reminder that this stretch once passed through a tunnel.
Horse Bridge (217), Shipton on Cherwell, Oxfordshire
As the canal passes south towards Oxford, it joins the River Cherwell just below Enslow and shares a common course for ¾ mile before they separate at Shipton Weir Lock. Where the canal and river join, the river is crossed by a steel bridge to allow the towpath to continue from canal side to river bank.
Horse Bridge (217)
Built in 1909 this is an elegant segmental arch crossing the River Cherwell at Horse Bridge Junction.
As the canal construction neared Oxford, the course of the river was used as part of the canal to reduce costs.
This view from the south shows Horse Bridge crossing the river which continues straight ahead; the mouth of the canal is to the right with Bakers lock just out of sight.
Horse Bridge (217)
The bridge is constructed of riveted steel supporting arches with angle-iron open X-shaped parapet work.
The appearance is far more "industrial" and functional than its cast iron cousins.
The approach ramp walling at either end is of red brick with shaped blue brick coping.
Isis Lock Bridge (243), Oxford
Crossing the northern end of Isis lock is Isis Lock Bridge, which is the most southerly and perhaps most photographed of all the iron bridges on the Oxford Canal (this is possibly more to do with its position in central Oxford than the bridges undoubted innate elegance!). The lock gives access to (after a sharp right turn) the Sheepwash Channel, which in turn leads into the River Thames. This is an area of complex waterways, some natural (the Thames and its tributaries) and others manmade (the Oxford canal and basins).
Crossing the northern end of Isis lock is Isis Lock Bridge, which is the most southerly and perhaps most photographed of all the iron bridges on the Oxford Canal (this is possibly more to do with its position in central Oxford than the bridges undoubted innate elegance!). The lock gives access to (after a sharp right turn) the Sheepwash Channel, which in turn leads into the River Thames. This is an area of complex waterways, some natural (the Thames and its tributaries) and others manmade (the Oxford canal and basins).
Isis Lock Bridge (243)
Looking south through the bridge towards Isis Lock with the Sheepwash Channel beyond and to the right.
The history of the junction of the Oxford Canal and the Thames is complex. As originally conceived, the junction was a flash lock at Hythe Bridge (1790) which was replaced by a broad lock on the present Isis Lock site (1795-7) by David Harris. This allowed wide barges from the Thames to access the Canal Company wharves at Worcester Street but was in-turn rebuilt as a narrow lock in 1844.
Isis Lock Bridge (243)
A view from the south side of the bridge with Isis lock on the right.
Through the bridge can be seen the canal which once led to the canal company wharves at Worcester Street but now ends at Hythe Bridge Street.
The bridge is visually identical to the Fenny Compton Turnover Bridge (137A) and has the same construction; each face of the bridge being a single casting connected together by cast iron plate decking and arch soffit.
The approach ramps and abutments are walled with a mix of blue and dark red brickwork in English bond and header bond on the curved sections. The coping is of dark blue shaped brick.
A view from the south side of the bridge with Isis lock on the right.
Through the bridge can be seen the canal which once led to the canal company wharves at Worcester Street but now ends at Hythe Bridge Street.
The bridge is visually identical to the Fenny Compton Turnover Bridge (137A) and has the same construction; each face of the bridge being a single casting connected together by cast iron plate decking and arch soffit.
The approach ramps and abutments are walled with a mix of blue and dark red brickwork in English bond and header bond on the curved sections. The coping is of dark blue shaped brick.
Isis Lock Bridge (243) is commonly dated to 1790 (Historic England listing c1790), but on stylistic grounds this seems unlikely.
Its apparent identical form and construction when compared to bridge 137A is revealing and suggests a later date. We know that the Fenny Compton bridge cannot have been built before at least the partial unroofing of the tunnel in 1838-40, and such a date would therefore also seem likely for the Isis Lock Bridge construction. This would fit nicely with the date of the Isis lock rebuilding in 1844, when it was reconfigured as a narrow lock. A construction date sometime in the 1840s would thus seem to be a reasonable supposition.
Its apparent identical form and construction when compared to bridge 137A is revealing and suggests a later date. We know that the Fenny Compton bridge cannot have been built before at least the partial unroofing of the tunnel in 1838-40, and such a date would therefore also seem likely for the Isis Lock Bridge construction. This would fit nicely with the date of the Isis lock rebuilding in 1844, when it was reconfigured as a narrow lock. A construction date sometime in the 1840s would thus seem to be a reasonable supposition.
Conclusion
The iron bridges we see crossing the Oxford Canal are the result of both industrial innovation and historical circumstance.
Many were built by the growing industrial empires (Horseley Ironworks, Britannia Foundry) that developed during the innovative frenzy of the Industrial Revolution. The need to build such bridges, especially in the northern section of the canal, was however driven, not by the availability of the new technology, but by commercial threats from other transport providers; firstly the Grand Junction Canal and then by the developing railway network.
These commercial threats spurred the Oxford Canal Company to modernise and improve the canal giving us a legacy of iron bridges that combine technical achievement with aesthetic grace and elegance. They provide an interesting comparison with the simplicity and rustic charm of the southern lift bridges previously described.
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