Sunday, 16 March 2008

New GE19 bridge gains temporary extension

I was on a train out of Liverpool Street earlier today and was surprised to see the new GE19 bridge had gained an appendage on its west end.

I went back this evening with a camera:
In a couple of month's time the bridge is going to be slid to the left over the main line, and this extension ought to guide the bridge itself onto the western abutment. They've made it curve upwards slightly suggesting they the structure to sag on its way across. The extension looks long enough that by the time the bridge is in its final position, the tip could be hovering somewhere over Brick Lane. (see map)

(by the way, the line of concrete blocks in the foreground correspond roughly with where the back wall of the platform at Shoreditch was before the cutting was filled in)

Meanwhile just down the road, the Shoreditch High Street bridge has gained its uprights and looks close to ready to go:
The hoarding advertises the bridge move and road closure in two weeks' time and says the "largest crane in the UK" will be used. Bus users are advised to allow "up to 40 minutes extra" for their journeys.


Anonymous said...

It's a pilot beam used to align the bridge during the push. They are frequently used by the Army Royal Engineers. Roughly the civil engineering equivalent of tying a light thread to an arrow/rocket which is in turn tied to a small diameter rope tied to a hawser etc - used at sea.

Anonymous said...

Its actually called a launch nose. Its purpose is that the bridge beams do not have the capacity in bending beyond a certain point of cantilever. It is very different from army type bridges, typically based on the original Bailey bridge design which are modular in construction, and designed for push launch constructin.
The bridge across bishopsgate is that of a bow string arch, the first time that a bridge of this form with true hangers has been used for rail infrastructure in the UK. hope this is of some interest.