1. How are they going to remove the old bridge debris? I know there are barge cranes enroute but they can’t lift an entire bridge section.
1a. How do they cut the bridge sections into liftable segments without shock loading the crane?
They will use a combination of methods, cutting torches, shears, hoe-rams, hydraulic saws, possibly lances, etc..
1b. How do they get a man into position to cut the bridge sections? Is this torch work or some crane mounted ‘jaws of life’ type pincer machine?
They will probably have barges with manlifts/aerial buckets etc..
And demo shear such as this
2. How do they get the barges to the bridge and keep them there? Presumably they would set the anchors upstream and the barges would be positioned downstream where the bridge debris is. Likely they would triangulate the anchors to prevent side shifting. It seems like the barges need to be upstream of the bridge but they can’t get there… yet.
They will have barges with spuds either on the bow or stern, or all four corners to locate the barges securely.. I'm not sure of the depth of the water . in some instances they may sink or ground the barges.. load them with debris, then refloat the barges. Same with the barge mounted cranes.. There is a barge mounted crane called the "century" owned by the Port Authority of NY and NJ, that has a 1000 ton capacity if floating.. if its grounded the capacity goes up a great deal..
There will be a number of set ups like this, on a much larger scale...
