Forth road bridge how long

The main cables are anchored at each end to take the 13, tonnes of total load in each cable. The tunnel lengths vary between 56 and 79 metres. The suspended span decks are hung from the main cables by sets of four hanger ropes with diameters of These hanger sets take loads of and tonnes.

Between and all these hanger sets were replaced without interruption to traffic. The deck on the main and side spans carries traffic loadings to the main cables via the hangers and does not contribute significantly towards the resistance of the truss to global effects. On the main span the deck is an orthotropic stiffened steel plate. However, on the side spans the deck is of composite construction with a mm thick reinforced concrete slab on steel beams. On all the suspended spans the surfacing is limited to a thickness of 38 mm.

The pier from the north tower was sited on the Mackintosh Rock, a whinstone outcrop that made an ideal foundation. The south tower was located about as far from the shore as the depth of bedrock would allow the construction of a foundation with compressed air working. Caissons were used to enable the pier to be founded on sandstone some 32 metres below high water. Pier defences were constructed around both piers in the late 's to withstand collision loads from shipping.

The main towers are of welded cellular high tensile steel construction and rise up over metres above high water level. The maximum thickness of the steel in the towers is about 25 mm. These towers were strengthened in the late 's to take the ever increasing weights of heavy goods vehicles crossing the bridge.

The approach viaducts are significant structures in their own right. Nicola Sturgeon, who was then deputy first minister, said the project would be completed by the end of The bridge's technical director Mike Glover said the weather in the Firth of Forth had been "particularly unkind", especially at the point when they were m in the air attaching cables.

More than 15, people have been involved in the project since the inception of plans for a new bridge in The structure is m above high tide ft , equivalent to about 48 double decker buses stacked on top of each other. The steel required for the bridge deck weighs a total of 35, tonnes - equivalent to almost Boeing s.

The combined steel required for North and South viaducts weighs 7, tonnes - enough to make another 23 Kelpies. The bridge has windshielding to almost entirely eliminate the need for closures during the frequent periods of high winds in the Forth estuary. Cables can be replaced with more ease than on the Forth Road Bridge - it can be done as part of normal maintenance works without closing the bridge.

The foundations of the bridge are large caisson - circular steel structures - sunk into the mud of the estuary to bedrock level. The south caisson is the height of the Statue of Liberty. It is 35m in diameter and when it was constructed it was 50m in height.

At the southern tower they poured 16, cubic metres of concrete over a period of 15 days continuously from barges on the river. Once it is fully operational there will be no pedestrian access to the bridge, instead people will be able to walk across the existing Forth Road Bridge.

However, an online ballot was held to select 50, people to walk across the new crossing on the weekend of Saturday 2 and Sunday 3 September. The "once-in-a-lifetime" opportunity attracted applications from more than , people, mainly from Scotland. About 5, people entered have postcodes from elsewhere in the UK and the remaining are from the rest of the world, including the United States, India and one single entrant from Slovakia. In addition to this, a further 10, people from local schools and community groups on both sides of the Forth will be able to walk on the bridge on Tuesday 5 September, the day after its official opening by the Queen.

It has also been announced that she will be accompanied by the Duke of Edinburgh, in his first official appearance alongside the Queen since retiring from solo engagements. Other events on the day will include a welcome address by First Minister Nicola Sturgeon and a blessing by the moderator of the General Assembly of the Church of Scotland.

Scotland's Makar, Jackie Kay, will read a poem specially commissioned for the occasion and there will be live music performances. Queen to open Queensferry Crossing. The troubles of the Forth Road Bridge. The bridge that should never close. Last bridge section slotted into place. The result is the most impressive concentration of very large bridges anywhere in the world. Why a second Forth Road Bridge?

The existing road bridge had for many years been carrying volumes of traffic far in excess of what was planned at the time it was built. This led to structural loads much larger than originally forecast, and has also caused one of Scotland's worst bottlenecks, especially for traffic heading south from Fife to Edinburgh on weekday mornings.

Additionally, corrosion began to appear in the steel strands making up the main suspension cables. The two factors together resulted in fears that use of the bridge by heavy vehicles might have to be restricted. Work began to see if the suspension cables on the existing bridge could be replaced or strengthened, but it became clear that even if this were possible, the work would cause considerable disruption for a prolonged period of time.

The Scottish Government therefore looked at building a new crossing over the river, something first considered but not pursued in the s. After a review of various bridge and tunnel options, the Government announced late in that it intended to build a cable-stayed bridge designed to carry road traffic.

Continues below image Construction on the new bridge began in , with completion planned to take 5 years. Bad weather especially high winds that repeatedly stopped work on the bridge pushed back the completion date from late until spring , and then until summer In the meantime a structural issue caused the complete closure of the existing Forth Road Bridge at the end of and into early , bringing home the importance of the new bridge to Scotland's economy.

The scale of the underlying traffic problem is clear from a few headline figures. By the late s, the four ferries on the route were between them making 40, crossings each year and carrying 1. In its first full year of operation, , the Forth Road Bridge carried around two million vehicles in each direction.