OK, I got some new info on this and some new pics. Starting at 6AM on Sunday July 17, they're supposed to take a 20 hour line outage and remove what's left of the original bridge and crane the new one into place. Should be interesting. The new road clearance is supposed to be 13'-5", which is an increase of 20" over the original 11'-9".
Where I thought they were building a new abutment to place a new bridge next to the existing? Nope, looks like they just built up a new retaining wall to support the crane:
And the 'empty' half or the existing bridge is now completely gone, and they built up a new support wall on top of the original abutment, with maybe 18-24" of clearance on the original abutment (probably can't see it too well from this angle, but the new concrete wall is set back from the original stone wall):
And here we have half of the new bridge ready to be dropped into place. I didn't figure it all out until I looked at the pictures, but if I had to guess I'd say that girder holding this thing off the ground is actually part of the bridge, and if I'd measured it it is probably 20". So that part will sit on top of the original abutment, and the flange/trackbed part will fit nicely on top of the new white concrete wall thing:
So it does appear that yes, the grade of the track is not changing at all- they're just using a lower profile bridge structure. So I'm guessing they'll shut the line down, remove the track and haul off all the built-up ballast, then cut away the bridge and lift it off with the crane. Then they'll have to add the concrete risers on that half also, then they'll lift both halves of the the new structure into place and do whatever fastening they need to do (I would think it's more than just held into place with gravity?), then build up the ballast to the proper height, then re-install the ties & track and tie it back in. All in 20 hours!! At least that's my guess. There's only that one section of bridge there right now- I'm assuming they will be bringing a second half in sometime this week, but who knows. We''ll have to wait and see I guess....