Belfast cross-harbour road and rail bridges


Duration:4 years

Cost:£27.7m (£48m today)

Country: Belfast, UK

What did this project achieve?

Significantly improve road and rail links for the city of Belfast

By the 1980s the crossings over Belfast's River Lagan – including the Queen's Bridge and the Albert Bridge - were struggling to cope with traffic.

Congestion in the city centre was getting worse and journey times slower. Air pollution from cars and lorries was rising.

City authorities had been trying to deal with Belfast's traffic problems since the 1960s with little success. An elevated road around the city had been suggested and designed but only a short length of dual carriageway was ever built.

The 1990s saw major regeneration work across the city. As part of this 2 new bridges were planned for the River Lagan – both just upstream from the harbour area.

The Lagan Road Bridge was built to help relieve congestion and air pollution in the area. The 790m bridge connects the M2 in the north to the M1 in the south.

The parallel Dargan Road Bridge was designed to connect 2 previously separate rail networks. At 1490m, it's the longest bridge in Ireland.

The new bridges were opened by the Queen in March 1995.

Difference all the crossings have made

The new bridges improved Belfast's infrastructure by connecting road and rail networks – they're seen as a major economic lifeline for the city.

The Lagan Road Bridge has made it easier for cars and lorries to cross the area. 90,000 vehicles now use the bridge every day. It's eased congestion and brought down pollution levels.

The Dargan Rail Bridge speeds up rail journeys, cutting times to Dublin, for example.

The project helped get people and goods around the area more easily, so helping boost the local economy.

The 2 bridges are credited with acting as a catalyst for economic development right across Northern Ireland.

How the work was done

Engineers built both bridges using a concrete box construction. The segments were cast in a specially built factory – 828 were needed for the land spans and 230 were used for the river spans.

Heavy duty crawler cranes were used to get the land segments into place. A crawler crane is a mobile unit with a telescopic arm that uses crawler tracks to move. The tracks are similar to what you'd see on a tank.

River segments were floated into position by strapping them to the deck of a flat-top barge and then towing it out into the river using tugboats.

Engineers used computer simulations to test the barges' capability. This helped them calculate, for example, how much ballast the boats needed and where it should be placed for safe working.

The concrete segments were 4m long, up to 5m deep and weighed up to 95 tonnes.

Engineers glued the segments together using epoxy resin – the first time this technique had been used in Ireland.


There is no turning back on the road to peace.

Prime Minister Tony Blair

on the Northern Ireland peace process.

Fascinating facts

Designs for the project were assessed by the Royal Fine Art Commission, an independent body that advises government on aesthetics in public buildings.

The project was completed in 160 weeks and handed over to the client 7 weeks ahead of schedule.

The bridges are viewed as being part of the 'peace dividend' – an increase in economic stability and activity that came with the Northern Ireland peace process of the 1990s.

Many believe the bridges couldn't have been built without the reduction in hostilities the peace process brought.

People who made it happen

  • Clients: Northern Ireland Road Service, Northern Ireland Railways
  • Contractors: Joint venture between Graham Construction and Farrans Construction

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