Wednesday, June 20, 2012

Bridge Building Over High Beck

Last week saw us on two work parties starting the mammoth job of rebuilding the bridge on the Liza path over High Beck.  This job was made harder by the huge quantity of midges, even the National Park & Forestry staff said they had never known as many in one place.

The helicopter had delivered the materials a few weeks ago all we had to do was assemble them (and a bit more).

The abutment on one side had been washed away so the first job was to dig out new foundations & collect a lot of stone to build with.


Large stones were used as the facings for the abutment with smaller ones as infill


Andy was collecting stones whilst Karen helped build the abutment, it was very similar principles to dry stone walling, although we were using a little concrete to hold some of the stones in place


It takes  plenty of deliberation over which stones fit best where


Andy busy mixing the concrete.


At the end of Tuesday the abutment was almost complete, we needed to raise it about 3inches & fill the middle with concrete.


So Thursday we were back on it, thankfully there was a little breeze & only a few midges.


The abutment was finished, now the small matter of moving the beams onto it.  The beams were 11m x 36cm x 23cm so not light


Using cantilever principles & some good old brute force the beams were slowly lifted into place


Using the lats from the old bridge as a rest slowly the beams are lifted higher as more are inserted


And finally the first beam is rested on both abutments


It’s tiring work.


Then its time to start on the second beam, Andy, Angus & Julian act as a counter weight as the beam is moved into place



Once the beam is on both abutments the last job is to roll the beam over


Job done, it’s been a hard but rewarding two days work


Although the beam is not in its final position & it doesn’t actually matter if its not completely level we haven’t done badly that’s 3.3degrees off level.


There are a few more work parties needed to paint & assemble the final bridge.

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