Question/Dilemma about High Bridge Construction...?

[NW Mailing List]

On Fri, May 9, 2014 at 5:54 PM, Gordon restated:


> As I understand the original question it is: Why do construction photos show

> a track in the center of the trestles --not offset to one side?


Only the last photo shows the location of the construction span and at
that point the legs of the trestle are still being assembled. The
centered trestle may have been temporary, to provide balance and equal
stress on the whole structure, and to provide an equal reach to both
sides of the project by the crane. It would take additional photos
from later in the project to see just what happened next. It could be
that once the whole span was completed, the construction crane moved
back across the bridge, moving trestle sections to the final offset
location as it went (with an assist from a crane on the existing
trestle to lift the far end of the span just vacated by the crane).

Bruce in Blacksburg