Menai Suspension Bridge

Menai Suspension Bridge

 

For centuries, travel to Anglesey from the mainland was often hazardous. Ferries traversed the Menai Straits at various places, but the currents are tricky and numerous boats capsized or ran aground, often with loss of life. In 1800, Ireland joined the UK through the Act of Union. This meant that the numbers of people wishing to cross the Straits increased as politicians commuted to and from Ireland to parliament in London. The route from London to Holyhead became an important roadway, representing a physical link between parliament and Ireland. Although well travelled, the journey was still notoriously dangerous. In 1819, a civil engineer called Thomas Telford began working on ambitious improvements to journey between London and the port of Holyhead. Recognising the danger to travellers that crossing the Straits involved, Telford designed a groundbreaking piece of civil engineering – the Menai Bridge. Completed on 30 January 1826, the Menai Bridge was a triumph of civil engineering – the biggest suspension bridge in the world at the time. Sixteen huge chains held up 579 feet of deck, allowing 100 feet of clear space beneath. This allowed tall sailing ships navigating the seaway to pass underneath, whilst spanning the Straits at its narrowest point. The Menai Bridge not only made Telford’s reputation as a civil engineering superhero, it also dramatically reduced the time and danger it took to travel from London to Holyhead. Along with Telford’s other improvements to the road, the journey time was cut 36 hours to 27.

 

Thomas Telford was born at Glendinning, Eskdale (near Langholm, Dumfries and Galloway) on 9 th August 1757. John Telford, his father, was a shepherd and died in November the same year so the family was very poor. Thomas received elementary education at the local school and also helped out with various jobs around the area. He was known locally as ‘Laughing Tam’. He was treated very kindly by certain local families with whom he maintained contact throughout his life. At the age of 14 Thomas was apprenticed to a stone mason, and examples of his work can still be seen in Langholm and Westerkirk. In 1780 he moved to Edinburgh and worked in the ‘new’ town around Princes Street. In 1782 he travelled to London and worked on Somerset House under Sir William Chambers and gained promotion to first class mason. He then worked in Portsmouth dockyard as a supervisor from 1784 to 1786 where he developed his design and project management skills.

 

In 1786 he was employed by William Pulteney to improve Shrewsbury Castle and was appointed Surveyor of Public Works for the County of Shropshire, a post he held until his death. He was responsible for building 3 churches and over 40 bridges in the county, the first being Montford Bridge completed in 1792. Bewdley and Bridgnorth were among his later masonry bridges, and his first iron bridge at Buildwas (1796) advanced the art of building in iron considerably, with many of his similar bridges in various parts of Britain remaining in use today. Telford was appointed to the Ellesmere Canal Company in 1793 and made his reputation as a civil engineer while responsible for building what is now the Llangollen Canal, including Chirk Aqueduct (1801) and the revolutionary Pontcysyllte Aqueduct (1805). Following work he had done for the British Fisheries Society, in 1801 he was appointed by the Government to survey and improve communications in the Scottish Highlands. Over the next 20 years or so he was responsible for the construction of nearly 1000 miles of road, over 1000 bridges, scores of harbours, churches and manses, and the Caledonian Canal running 60 miles from the west to the east coasts.

 

Telford was also commissioned to design the Gotha ship canal in Sweden which he surveyed in 1808, and planned the whole 114 miles before returning to Britain two months later. The canal was eventually completed in 1832. In 1811 Telford was appointed to survey the road from Shrewsbury to Holyhead and eventually in 1815 he was commissioned to improve the whole route from London to Holyhead, which included such major works as Waterloo Bridge at Betws y Coed, Nant Ffrancon pass in Snowdonia, Stanley Embankment near Holyhead and, of course, Menai Bridge between Anglesey and mainland Wales. The commission was extended in 1817 to include the Bangor to Chester road which involved the headlands at a Penmaenmawr and Penmaenbach and crossing the Conwy estuary with the embankment and Conwy Suspension bridge. The new route from Llangollen to Bangor was open in 1819 and the whole commission was completed in 1826. In 1820 Thomas Telford was invited to become the first President of the Institution of Civil Engineers, the oldest professional learned society and qualifying body for the engineering profession in the world. Telford was instrumental in gaining the Institution its Royal Charter in 1828 and served as President until his death on 2 September 1834.

Brittania Bridge

Brittania Bridge

 

As rail travel became increasing popular in the mid nineteenth century, it was deemed necessary for a rail link across the Menai Strait for the convenience of MPs travelling to and from Ireland. The possibility of adding a rail line across the Menai Suspension Bridge was investigated, but found to be inappropriate. Therefore a second bridge across the Menai Strait was commissioned. This bridge would need to be at least 100 feet above the high water level to allow tall sailing ships to move underneath the bridge. It would also need to support two train tracks across its main span. To complete such a bridge today would still be considered a difficult prospect. The challenge was handed to Robert Stephenson, son of George Stephenson, who was one of the leading railway and civil engineers of the time. His design team also included William Fairbairn and Eaton Hodgkinson. Britannia Bridge TubeMany ideas were considered, but the favoured design would be a revolutionary new tubular design. This would incorporate two main spans of 140 metres and two additional spans of 70 metres made from giant wrought iron tubes. There would be two tubes for each span; one for each of the railway lines. At first it was considered by Fairbairn that the tubes would need support from chains in the manner of a suspension bridge to stabilise the structure. Tests and careful mathematical investigation showed that chains would not be needed.

 

By creating a tubular system, the forces of compression and tension acting upon the tube as the train travelled across would be dissipated or spread out across all four surfaces of the tube, and the bridge would retain its structural integrity. In other words, the larger surface area of the box girder allows the force to be dissipated more efficiently. This would result in being able to span a greater distance and carry the force of heavy loads crossing the bridge. The construction of the Britannia Bridge was started in 1846 and completed four years later in March 1850. The tubes were constructed onshore on the banks on the Menai Strait before being floated out into place and hydraulically pumped into position. At the same time Stephenson’s other tubular bridge in North Wales, the Conway Bridge, was also being constructed and their completion signalled the opening of the Chester to Holyhead railway. The Britannia Bridge remained in use and was claimed to be the most easily maintained railway bridge in Britain, until 1970 when the bridge caught fire. A group of local youths exploring the tubes of the bridge accidentally dropped their burning torch and the bridge caught fire. Some of the tubes were visibly sagging after the fire and the bridge was classed unsafe. It was not until four years later that normal rail services across to Anglesey were resumed.

 

During reconstruction after the fire the bridge changed dramatically. The tubes were no longer used and the deck was supported by arches spanning between the towers. The original towers remain but have also been altered to suit the new design of the bridge. In 1980, ten years after the fire a road deck opened above the railway on the bridge, which carries the A55 across to Anglesey. Stephenson and Fairbairn’s tubular design went on to influence many engineers, including Brunel and its principals are still widely used today. The Conway Bridge is still in its original tubular form and is still in use over 150 years later. A section of the tubes of the Britannia Bridge can be seen on the Bangor side of the Menai Strait, close to the bridge itself.

 

The Thomas Telford Centre, home of the Menai Heritage offices and exhibition, is a former schoolhouse that was refurbished in 2007. In the early 1850s, as the congregation of Porthaethwy/Menai Bridge outgrew the tiny church on Church Island, the well-known Bangor architect Henry Kennedy drew up plans for a new church along with an associated school, yard and schoolmaster’s house, with the church in a commanding position overlooking the entrance to the Menai Bridge. Land was donated by the Marquess of Anglesey, as was funding, and the school opened in 1854. Initially the school was a simple rectangular building with a small porch on the front. In 1878 an extension was added perpendicular to the back wall to accommodate an infant’s school. A new cloakroom was added in 1896 and the front porch extended in 1909. Founded in 1997, the Menai Bridge Community Heritage Trust (also known as Menai Heritage) seeks to preserve the historical and architectural heritage of Menai Bridge for the community.

 

The Exhibition tells the story of the two famous bridges, the engineers who designed them and the craftsmen who built them and what happened next. Thomas Telford and Robert Stephenson developed pioneering bridge designs and constructed road and rail crossings over the treacherous waters of the Menai Strait. They changed the nature of the journey between Dublin and London forever! Although there are steps to the front entrance, the building is fully accessible to wheelchair users at the rear entrance. Assistance dogs are welcome. There are toilet facilities for the disabled.

 

Location : Thomas Telford Centre, Mona Road, Menai Bridge, Anglesey LL59 5EA

Transport : Bangor (National Rail) then bus (62, X4, 42, 43, 47 and 57). Bus Routes : X4, 4, 4X, 4A, 42, 43, 44, 44A, 47, 53, 57, 58, 62 and 63 stop near by.

Opening Times : Wednesday + Thursday 10:00 to 17:00

Tickets : Adults £3.00;  Children (under 16) Free

Tel : 01248 715046