Menai Crossings

Year:1826 & 1850

Duration:7 years & 4 years

Cost:Unknown

Country: Wales, UK

What did this project achieve?

Build a bridge to move people or trains across the Menai Strait in Wales

The Menai Suspension Bridge was the first to cross the Menai Strait – a fast-flowing stretch of tidal water that was 1,300ft (400m) wide at its narrowest point.

Before the bridge went up the only way across the channel was by ferry. Engineer Thomas Telford was asked to survey the strait for a suitable crossing.

Telford recommended a suspension bridge as high banks and fast moving currents meant it would be difficult to build on the sea bed.

A suspension bridge would also be high enough to let tall ships pass under it – Admiralty rules at the time demanded clearance of 100ft (30m) above high water.

The Britannia Bridge was part of the expansion of the railways across the UK in the 1850s.

Engineer Robert Stephenson used a tubular design with trains running on tracks inside a rigid box girder structure.

Severely damaged by fire in 1970, the bridge reopened for rail services in 1974. It was further rebuilt to carry road traffic by 1980.

Difference the crossings have made

The Menai Suspension Bridge made it quicker and far safer to get people and goods from Anglesey to Wales.

The main source of income on Anglesey at the time was cattle farming. Getting cows from the island to markets on the mainland meant swimming them across the river. Valuable animals were often swept away or drowned in strong currents.

The bridge boosted the local economy and was particularly good news for local farmers who no longer had to swim their produce across the channel.

The Britannia Railway Bridge was the first direct rail link between London and the port of Holyhead. It reduced journey times between Anglesey and the capital.

How the work was done

Work on the 1,368ft (417m) Menai Suspension Bridge started in 1819 with the construction of towers on either side of the strait.

Project chief Thomas Telford used local limestone to build the towers with the stone quarried near the village of Penmon on Anglesey.

Engineers used 16 huge chain cables – each made of 935 iron bars – to support the bridge's 577ft (176m) span.

Each chain was 1,714ft (522m) long and weighed 121 tonnes. Workers soaked the iron in linseed oil between manufacture and use to keep it from rusting.

The Britannia Railway Bridge saw Robert Stephenson working with engineer William Fairbairn on a tubular design for the crossing.

Fairbairn constructed a 75ft (23m) long model of the bridge at his Millwall shipyard, south London, to test out some options for the structure.

Experiments on the model suggested that rectangular box girders would work better than elliptical tubes as 'tunnels' for trains crossing the bridge.

The 1,512ft (461m) rail bridge opened in 1850.

"​‌

I heard him then, for I had just completed my design, To keep the Menai bridge from rust By boiling it in wine.

Lewis Carroll

From the poem Haddocks' Eyes in Through the Looking Glass

Fascinating facts

The Menai Suspension Bridge appears on the back of the UK £1 coins minted in 2005.

Construction techniques used for the Britannia Railway Bridge influenced Isambard Kingdom Brunel's Royal Albert Bridge over the River Tamar.

The only tubular bridge still in use today is the Conwy railway bridge in north Wales.

People who made it happen

  • Menai Suspension Bridge designer: Thomas Telford, first ICE president
  • Britannia Railway Bridge designer: Robert Stephenson, ICE president

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