Moments in Time: Two Bridges That Changed Everything

On a peaceful day the Menai Strait can look like a gentle river, glassy and green as it winds through wooded shores. But watch the powerful currents race past the town of Menai Bridge - or the turbulent whirlpools known as the Swellies - and another identity is revealed.

The strait is a funnel of the Irish Sea, surging with incoming tide from both east and west.

For thousands of years this stretch of water has challenged human ingenuity. Causeways and ferries carried passengers and livestock across ever-shifting sandbanks and channels. Many farmers swam across with their animals - and some didn't make it. In 1785, one ferry boat went down with 55 people aboard. Admiral Nelson himself spoke of the perils of navigating a tall ship through the strait.

Inspiration, Innovation, and Industry

© National Library of Wales, via the People's Collection Wales

In January 1826 a marvel of engineering ended Anglesey's isolation forever. The opening of the new Menai Suspension Bridge linked the new A5 road from London to Holyhead, the port for Ireland. This was the first large iron suspension bridge in the world, a graceful and magnificent masterpiece.

In March 1850 a second bridge was opened to the west, the Britannia Tubular Railway Bridge. This too was a radical, pioneering piece of engineering that astonished the world. 

Menai Suspension Bridge: The world's first large iron suspension bridge

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Gradually the arches, piers and towers rose higher and higher.  The bridge was to have a final height of 45.7 metres, with the timber deck 30.5 metres above the waterline. The Admiralty demanded enough clearance for the tall-masted sailing vessels of the day.

The length of the  bridge measured 304.8 metres, with a central span of 176.5 metres. This section was suspended by 16 wrought iron chains. Each weighed over 23 tonnes, and it took 150 labourers to raise them with pulleys, turning a capstan in time to music. The chains were anchored deep into the bedrock on both shores.

Workers completed the bridge in 1825, and they opened it to the mail coach service in January 1826, amidst public rejoicing. Travel time from London to Holyhead was cut from 36 hours to 27.

The Menai Bridge became famous worldwide, and even featured in a nonsense poem in Lewis Carroll's Through the Looking Glass. Carroll jokes about a scheme to prevent the bridge rusting by boiling it in wine. In reality the chains were kept in condition with linseed oil.

All traffic paid a toll to cross until 1941. A steel deck replaced the timber one in 1893, and steel chains replaced the iron in 1938-40.

From Menai Bridge town, walk today along Lôn Cei Bont for a spectacular view of the bridge from the waterfront, with soaring perspectives. For a more distant view, with the mountains of Snowdonia behind, stop off at the lay-bys on the Holyhead Road.

Britannia Tubular Railway Bridge: A wonder in wrought iron

It was Anglesey's good fortune to have another engineering genius design its second great bridge across the Menai Strait. Robert Stephenson (1803-59), son of railway pioneer George Stephenson, chose the site, 1.6 km to the west of the first bridge,  because the Britannia Rock, mid-Strait, could provide good foundations for the central pier. Work began in 1846.

It was challenging and dangerous work - a memorial in the churchyard of St Mary in Llanfair Pwllgwyngyll records the names of 20 labourers and others who died during the construction and repair of the bridge.

On the advice of the structural engineer and shipbuilder Sir William Fairbairn, Stephenson decided to do away with supporting chains and to let the trains run through rigid rectangular tubes of wrought iron, supported by towers of local limestone. This was a revolutionary scheme: the longest previous wrought-iron span had measured 9.6 metres. These would be ten times longer!

Each of the central tube sections was 140 metres long and weighed 1,830 tonnes. Side sections were 70 metres long. Rivets? Approximately 2 million!

To build the bridge, workmen floated the massive central sections on pontoons, jacked them up 32 metres and then secured them by the stonework - again, high enough for the tall ships of the day to sail below. Designers crafted the towers in the then-fashion- able Egyptian style and flanked the ends of the bridge with stone lions carved by John Thomas. These beasts passed into Anglesey folklore. The bridge was opened at last in March 1850 - with a concert performed in the new tunnel.

The Chester and Holyhead Railway became part of the LNWR (London & North Western Railway) in 1859. For commerce, industry and passenger travel, a new era was beginning for both Anglesey and Ireland.  

The Britannia becomes a double-decker

On the evening of 23 May 1970 some boys dropped  burning torch on the bridge; it caught fire and burned across the span. The intense heat weakened the iron, and officials declared the bridge unsafe.

Engineer Sir Charles Husband supervised reconstruction, using the original stone piers but employing steel arches for support. The rail crossing was operating again by 1972, and eight years later a concrete road deck was added on top.

The changes did not deter peregrine falcons from nesting on the tops and hunting pigeons from the Treborth Botanical Gardens!

Travellers along the A55 expressway or on the West Coast Mainline rail line get little impression of the grandeur of Britannia Bridge as they speed towards the port of Holyhead.  However if you walk along the footpaths between the shores of the Strait and Llanfair Pwllgwyngyll, the view of this massive structure is seriously impressive.