Address: North Queensferry to South Queensferry, Edinburgh, Scotland

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New Forth Bridge History

The old bridge served the area for over 50 years, carrying 60,000 vehicles a day. As with all major structures, periodic safety checks take place and, in 2005, it was found that corrosion in the cables had reduced strength by 10%. In 2007, it was decided to build a new bridge. If it wasn’t built, it was thought that by 2019 the old bridge could have been closed, resulting in major chaos and billions of pounds of lost trade over a period.

Construction began in 2011 and the design chosen was a cable-stayed bridge. It is 1.7 miles long, making it the longest bridge of its type in the world. It is also the highest bridge in Britain.

The contractors were Forth Crossing Bridge Constructors (FCBC) and they comprised of the firms of Dragados, Hochtief, American Bridge and Morrison Construction. Their cost was £790 million, but the overall cost of the whole project was £1.35 billion.

The new bridge is simply part of the M90 motorway, with drivers able to travel 70 mph when travelling across. This is in contrast to the 40 mph limit of the old bridge. To allow motorists to become accustomed to the new, faster speeds, authorities had a 40 mph limit in place on the first day and, gradually over a few days, raised this limit to 70 mph.

Regarding construction, there are 23,000 miles of cables and another feature is the wind-proof protective fence along the sides. The old bridge had frequent closures due to high winds, with the new protection thought to make wind closure on the new bridge unlikely.

The new bridge is closed to pedestrians and cyclists, with the old bridge remaining in use solely for the use of public transport, cyclists and pedestrians. The corrosion problems have been rectified using dehumidifiers.

The new bridge was opened to traffic in August 2017, with the official opening by Queen Elizabeth II on 4th September, a few days later. This was 53 years to the day since she opened the old bridge.

The new bridge is named ‘The Queensferry Crossing’. Aptly so as it connects North Queensferry (on the north bank) with South Queensferry (on the south bank). These places were so named because St Margaret of Scotland, who was an 11th century queen, ordered a ferry crossing to be established between these two places to assist pilgrims in reaching St Andrews.

 

Old Forth Bridge History

With Edinburgh on one side of the river and Fife on the other, it’s little wonder that there have been crossings here for centuries. In the 11th century a ferry service operated that transported pilgrims from Edinburgh to Dunfermline and St Andrews, a crossing that was named the ‘Queen’s Passage’ after the wife of Malcolm III. And Mary Queen of Scots is known to have used the ferry in the 16th century during her legendary escape from Loch Leven. Since then , the crossings have continued to this day with the old road bridge carrying 30,000 vehicles a day.

Ferry services continued between these two points for over 800 years, with the service becoming busier with the increase in population and economy. As with many other road bridges around the country, ideas were mooted in around the 18th century.

A report in 1811 recorded the annual crossing of 83,000 people, 6,000 carts and 44,000 animals. Plans for a chain bridge were suggested and rejected in 1817. In 1879, the collapse of the Tay Bridge made people suspicious of bridge construction, but in 1890 the Forth (rail) Bridge was completed and this carried rail passengers. By the 1920s, the increase in motor traffic made the introduction of a permanent road crossing a necessity. In 1929, the eventual designers Mott, Hay and Anderson were involved in the survey to pinpoint the ideal type of crossing and location. They identified three possible locations.

The economic crisis of the 1930s and the Second World War put plans on hold, with the ferry companies now expanding their fleet to cope with increased demand. At this point they were making over 100 ferry crossings a day. They were carrying 1.5 million passengers and 800,000 cars annually.

In 1947 an Act of Parliament was passed to build the bridge and the route over Mackintosh Rock was chosen.

To ensure that it was built by a UK firm, there was an amalgamation of three firms for the project. They were Sir William Arrol and Co, Dorman Long, and the Cleveland Bridge and Engineering Co. The company was known as ACD. The plans were passed in 1958 and construction began. On 4th September 1964 the bridge was opened by the Queen and the Duke of Edinburgh with a 21 gun salute fired from Royal Navy ships in the estuary.

The total cost of construction was £19.5 million. Toll revenue was taken from the day of opening and by 1993, the cost of the bridge and interest had been recouped. The toll taken thereafter was invested in the maintenance and operation of the bridge until in 2008, all Bridge Tolls were scrapped in Scotland and the bridge became free to cross.

When opened, it was the bridge with the fourth longest span in the world. The central span, the part between the two towers, covers 1,006 metres, and the two smaller spans are both 408 metres long. The overall length including viaducts is 2,512 metres.

The two main towers are made of steel with a maximum thickness of 25mm. They both bear distinctive St Andrews crosses. The north tower was built on Mackintosh Rock, which was a major reason for choosing this place to cross, whilst the south tower was built on the sandstone river bed. The St Andrews crosses were strengthened in 1990 and the tower legs were strengthened in 1998 to cope with the increase in traffic. There are two side towers, one on each bank, and these help to support the main cables which are anchored into the rock on both sides.

The main cables each comprise of 11,618 individual wires, with each wire being 5mm thick. The cables were constructed by spinning a few wires at a time across the river. They gradually built up to form the 600mm finished cable. They were painted, covered, and painted again. These two main cables support the bridge deck and traffic and are themselves supported by 768 vertical steel hanger ropes. The ropes are 57mm thick and vary in length from 2.4m to 90m. They were all replaced between 1998 and 2000.

The deck of the main span is a 38mm road surface on top of a steel plate, whilst the side spans are the same surface, but built on steel and concrete.

The structure allows two lanes of traffic in each direction as well as a cycle/footpath on both sides.

In 2007, the Scottish Government announced plans for a new crossing alongside the existing bridge. Work started in 2011 and it opened in 2017.

 

Forth Bridge Visit

With the development of modern road systems, you cross bridges at times without even knowing about it, or with a cursory glance down the river as you pass by – and I suppose the Forth Bridge is no exception. It’s only when you take the trouble to look at it in detail, or go down river and look back, that you see the full scale of it and appreciate the design, engineering and construction. 

It’s a long bridge, the longest of its type when built, and provides a decent spectacle, running parallel to the Forth Rail Bridge that crosses the river nearby.

There are foot and cycle paths that run on each side and provide great views, mainly due to the leisurely manner of the foot/bike crossings. They are reasonably wide and allow a maintenance car to use the paths when needed. It’s a great and memorable walk, and interesting when windy!