Jack Under the Wood

This photo came in with this morning's batch from the site of the temporary bridge on NC12 and out of context it might look a little strange, if not precarious:

So, what's going on here?

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      Yesterday, our crews installed hydraulic jacks underneath the bridge truss and began lifting it in order to remove the temporary roller bearings used to extend the bridge across the breach.  The jacks will also be used to lower the bridge onto the permanent bearings.  This is a very delicate procedure where the bridge is alternately supported on wood blocks and lowered with the jacks approximately  four to six inches at a time.  Eventually, the bridge will be lowered approximately two to five feet, depending on the location along the bridge alignment. 
  


      This week's NCDOT Now features video of the work on NC 12: