Saturday, 15 September 2012

Forth Replacement Crossing



The road and rail bridges over the River Forth are probably Scotland's most well known man-made sight. But the two bridge are going to become three. The construction of the Forth Replacement Crossing is now underway with completion planned for 2016. Roadworks have been going on for some time but there is now progress on the bridge itself. The new bridge is a cable stayed structure with three supports in the river. For the foundations cassions have been installed. There are basically huge steel tubes that are sunk through the river bed to the rock below and will be filled with concrete to form a base for the bridge's towers.

The new bridge is required because the existing road bridge, constructed in 1964, is suffering on-going corrosion and breakages in the main suspension cables that will reduce its capacity to carry traffic in the future. It's interesting that the rail bridge, completed in 1890, is now in good condition after repairs and repainting and likely to be in service for the foreseeable future.

This project should provide some interesting photographs in the next few years.

The Forth Rail & Road bridges

On the right there are caissions near each bank and a jack up barge where a third cassion will be sunk.
Cassions & jack up barge show where the bridges towers will be. 


Artist's impression of new bridge

3 comments:

  1. They missed their chance with the new design. They should have built a replica of the rail bridge with the road on it. If nothing else, it would have photographers flocking to take interesting pictures of 'the twins', and just think how much good pr they would have got.

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    1. You can't get the riveters these days!

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  2. That will be interesting. On a much smaller scale, a similar set of three bridges exists in Folsom California. The original riveted iron structure was dismantled and sold to another town, when the more modern concrete structure was put across the American river down stream from where it exits Folsom Lake. (Near Folsom prison...for any Johnny Cash fans out there...). Not too many years ago the old iron bridge was brought back and reassembled on its original piers as a pedestrian/bike crossing. Several years ago a big modern multi-lane unit was installed downstream of these to help with traffic congestion due to the growth of this area. Maybe I'll go photograph these for a post sometime...

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