special feature
What difference?
Wales played a unique role in the development
of the chain suspension bridge in Britain, supplying the iron that made new kinds of structures possible. Explore the story though the pioneering work of retired Naval captain, Sir Samuel Brown.
This essay was funded by
the ICE R&D Panel
Institution of Civil Engineers
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Chain Bridges and Welsh Iron
introduction |  first modern suspension bridges |  Captain Sir Samuel Brown + Thomas Telford |  gazeteer of Brown's works |  sources + reading list
Captain Sir Samuel Brown + Thomas Telford
In the early 19th century in Britain, the development of the suspension bridge was dominated by two men — iron chain cable pioneer Captain Sir Samuel Brown (1776-1852) and Thomas Telford (1757-1834), considered one of the great civil engineers of all time. Brown erected the first road suspension bridge in the country, linking England and Scotland in 1820 with his Union Bridge, and Telford followed five years later with the Menai Suspension Bridge, linking the Isle of Anglesey to mainland Wales. Both were using Welsh iron.
Brown and Telford were following the lead of James Finley (1756-1828), who was working in North America, as described in the previous section. Finley is considered the pioneer of the modern suspension bridge — a bridge with a rigid level deck suspended from a catenary cable. His first example dates from 1801.
Publications describing Finley's work reached British engineers just over ten years later. However, more time was to pass before British bridges appeared, taking advantage of later advances in the poduction of wrought iron to a consistently high standard.
Even so, several iron chain 'modern' suspension bridges were constructed in Britain before Brown's Union Bridge. In the Scottish borders, an iron chain bridge and an early iron wire bridge were erected over the River Tweed in around 1817 (the former was re-built a year later). However, the pre-1820 bridges were all footbridges, and none survive.
Indeed, Telford was experimenting with the potential strength of iron wire. Brown told him about his ideas for iron chain links. In 1817, Telford and Brown collaborated on a proposal to span the River Mersey with a road suspension bridge at Runcorn in Cheshire. When this proposal failed to become a real project, the race was on for who could build the first one in the country.
Samuel Brown was a navy man. He entered Britain's Royal Navy in 1795, was appointed commander in 1811 and retired with the rank of captain in May 1812. By all accounts, he was very interested in finding a replacement for the hemp ropes used at the time for the rigging, anchor and mooring cables of ships, and which often failed. In his search, Brown saw that wrought iron had great advantages. He hired London blacksmiths to make wrought iron anchor chains, and installed them on a ship in 1806. After 1816, all new warships commissioned for the Navy would be similarly equipped.
By 1812, with the financial assistance of his cousin Samuel Lenox, Brown had set up a chainworks at Millwall on the isle of Dogs in East London. It would operate as Samuel Brown & Co until 1923, then as Brown Lenox & Co. In 1818, on advice from Brown's Welsh blacksmith and co-patentee, Philip Thomas (1771-1840), the company opened a second works (managed by Thomas), nearer to sources of coal and iron.
To do this, it took over the Tappenden nail factory beside the Glamorganshire Canal at Pontypridd in South Wales, and set up the Newbridge Chain & Anchor Works, taking its name from the town's original name. The works would become a major employer in Pontypridd before coal mining took over, and only closed in 2000, 30 years after it last made chain cable. The last major order was for the QEII.
Brown Lenox was to be the Navy's sole supplier of chain for almost a century. It also manufactured perhaps Britain's most famous example of chain cable — the one that forms the backdrop to the best known photograph of Isambard Kingdom Brunel (1806-59), posing beside the gigantic anchor chains pressed into temporary use as the launch chain for his steamship, Great Eastern.
Meanwhile, Brown's first experimental chain bridge, which spanned 32m, was erected in the Millwall yard. He is quoted by the Editor of the Edinburgh Philosophical Journal (Vol 14, No.27, January 1826) as saying:
"In 1814 I erected a bridge, with the road or platform perfectly horizontal, on my premisses (sic) at Mill-Wall, where it still remains. This is effected by introducing perpendicular rods through the joints of the main suspending bars, and adjusting their length to the curve above, so that they form a series of straps for the reception of a row of bars on each side, placed edgeways, and extending the whole length of the bridge, parallel to the entrance. The beams being laid across these bars, the platform or road becomes quite horizontal; or an ascent may be given from sides to the middle, in the same plane as with the roads leading to the bridge. The span is 105 feet, and the iron-work only weighs 38 cwt. It was inspected by the late Mr Rennie and Mr Telford, who drove their carriages over it; and it has been considered by men eminent for their skill in mechanics, as a remarkable combination of strength and lightness."
Brown's subsequent Union Bridge is now the world's oldest surviving suspension bridge. Its foundation stone was laid on 2nd August 1819, and the bridge opened on 26th July 1820. It spans the River Tweed between Horncliffe in Northumberland and Fishwick in Borders, and so links England and Scotland, hence its name.
Like most of Brown's chain bridges, the Union Bridge uses round eyebar links of Welsh iron. These were supplied by the Brown Lenox Newbridge Chainworks. It might seem surprising that Brown used round eyebar links, as his patent in this field was for flat links and pins. The patent was taken out in 1817 and it represented Brown's main innovation. Finley had used long open links of square section bar iron. Presumably, Brown switched to round eyebar links for reasons of economy, as they could be made from the same round bar stock used by the chainworks for making ordinary chain links.
Among the engineers who would come to work under Brown were Alexander Mitchell (1780-1868), James Slight (1784/5-1854) and William Clegram (1784-1863). The latter worked on Brown's 1823 Brighton Chain Pier and the 1826 Warden Chain Bridge on the River Tyne at Hexham (see gazeteer).
For over five years, the Union Bridge was the longest suspension bridge in existence. Then, on 13th January 1826, Telford's groundbreaking, 304.8m Menai Suspension Bridge opened to traffic. It used the design of Brown's patented iron chain links (replaced by steel in 1938), manufactured by William Hazledine (1763-1840) at Shrewsbury.
Telford's bridge across the Menai Strait put the suspension bridge firmly on the map as a safe and economical way of creating wide spans. The form would be used increasing by many engineers, as well as by Telford himself. That same year, Telford's Conwy Suspension Bridge, spanning the River Conwy in northwest Wales was completed as part of improvement works to the Chester and Holyhead Road.
However, Telford's experience of the damage caused to the Menai bridge by high winds led him to be extremely cautious of large spans. As a judge in the competiton to design a bridge for the Avon Gorge at Bristol, he rejected all five finalists because their spans exceeded 182m. A second competition was held, won by Brunel with his design for Clifton Suspension Bridge, the flat bar iron chains for which were to be supplied by Dowlais Ironworks, Merthyr Tyfil — another outstanding use for Welsh Iron.
Construction of the bridge faced endless delays, and the chain links ended up as tension members on Brunel's Royal Albert (1859) railway bridge over the River Tamar at Saltash, Cornwall. Some 1,150 of the links on this bridge, out of a total of 2,800 or so, are Dowlais iron. Brunel was also responsible for Hungerford Suspension Bridge (1845, dem. 1863) over the River Thames in London, a footbridge with a main span of 206m — the longest suspension bridge in the world at the time. Dowlais supplied its 18mm-bars, with eye plates welded to them by Copperhouse Foundry in Hayle, Cornwall.
The Hungerford bridge was demolished in favour of Charing Cross Rail Bridge (1864), but its demise led to the completion of the Clifton bridge after Brunel's death, in part as a memorial by his fellow engineers, led by the Institution of Civil Engineers — work proceeded under the supervision of Sir John Hawkshaw (1811-91) and William Henry Barlow (1812-1902). Advances in suspension bridge design led to some changes and the need for stronger cables than Brunel had envisaged. The Hungerford bridge supplied 1,056 tonnes of its Dowlais ironwork, and 203 tonnes of new links were supplied by the Lord Ward Round Oak works in Dudley, West Midlands. The bridge finally opened on 8th December 1864.
Wales, and its iron, played a unique role in the development of the chain bridge, as the site of Telford's early pioneering suspension bridges and as a supplier of chain links for Brown's first groundbreaking bridge, as well as the many of his design that followed — though, unfortunately, few have survived.
Interestingly, Brown also designed two chain piers, both soon after the completion of the Union Bridge. The best known is Brighton Chain Pier (opened November 1823, destroyed by a storm 1896), mentioned above. The other was located on the Firth of Forth at Leith in Scotland, and was similar in design. It was constructed in 1821 and destroyed by a four-day storm in 1898.
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introduction |  first modern suspension bridges |  Captain Sir Samuel Brown + Thomas Telford |  gazeteer of Brown's works |  sources + reading list

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Captain Sir Samuel Brown
Portrait of Captain Sir Samuel Brown (1776-1852), with Brighton Chain Pier in the background.
Photo: courtesy East Sussex County Council and Stephen K. Jones
Union Bridge
Brown's Union Bridge (1820), the world's oldest suspension bridge built for road traffic. Its iron catenary chains have been supplemented with wire cables.
Photo: Stephen K. Jones collection
Union Bridge
Another view of Union Bridge.
Photo: Stephen K. Jones collection
Menai Bridge, Wales
The Menai Suspension Bridge (1826) by Thomas Telford. It used Brown's patented iron chain links (replaced by steel in 1938).
Photo: Stephen K. Jones collection
Hungerford Suspension Bridge
Brunel's Hungerford Suspension Bridge (1845, dem. 1863) over the River Thames in London. It's iron chains were made of Welsh iron, and they eventually ended up on the Clifton Suspension Bridge.
Image: courtesy Stephen K. Jones
Brighton Chain Pier
A dramatic photo of the seaward end of the four-span Brighton Chain Pier (1823), by Brown. It seems that it is this pier is the only subject painted by both J.W.Turner and John Constable.
Photo: Stephen K. Jones collection