To be more precise, it's a viaduct over an expressway. I spotted that video showing a viaduct in China built in 43 hours via a blog post at ZeroHedge
http://www.zerohedge.com/news/2015-11-26/caught-tape-china-builds-bridge-just-43-hours
https://www.youtube.com/watch?v=vz_j_BEkVCQ
That is rapid bridge replacement. MTO is currently doing this on ON-417 in Ottawa. MTO has done this on several Bridges on The Queensway (417) over the last five years now.
OK, they didn't do it in 43 hours, but they never closed it all while they replaced it.
3 330' spans (single track) over Missouri River, Blair NE in the earl/mid 1920s. Chicago & Northwestern Railroad did it. To my knowledge, with no fatalities.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.blairhistory.com%2Flandmarks%2Fblair_bridge%2FBRG0018_650.jpg&hash=aad36cc07462d6413326627fca2c259cc782a36c)
So, what you're seeing in the picture, the span furthest to the right is the remaining original early 1880s span with a supporting trestle being erected beneath it. The center span has had the original span removed after it was supported by the trestle, and the trestle will support the new span till it is structurally complete and can hold itself. The span on the left is complete, and the temporary trestle has been removed.
The left span and the center span cannot have simultaneous trestle structures as that would block river traffic. With the trestle supporting the track at all times, the delays to passing trains were minimal. Also, most of the heavy equipment used to take down and erect the bridges was mounted on rail cars, and they could be wheeled in and out rapidly to clear the tracks for passing trains.
I don't know how long it took, I'd think at least one spring and summer, if not more.
The original spans were not wasted, they were taken to Wyoming in pieces and reassembled. They were shortened, and that allowed them to carry the heavier trains in use.
NJ has done this in a few locations, with more coming. Route 18/1 and Route 4/Jones Road are two examples.
CN (Canadian National) did the same thing when they replaced the Oshkosh, WI Fox River drawbridge on their Chicago-western Canada mainline in 2012. They only had to detour trains for a day or so when they swapped the new rolling bascule span for the old 1899 lattice-truss swing span. Ditto when they replaced the two fixed lattice-truss approach spans in that crossing for shorter simple beam spans as part of that project.
Mike
I recall them doing something similar in Utah, I believe on I-215 or maybe I-15 or I-80, but I think it was the bypass. Either way, they built the entire bridge right by the old bridge. They tore down the old bridge (not nearly as fast), and in one night, closed the road, and moved the new bridge on hydraulic lifts onto the roadway and into position and anchored it in. Bridge opened, ready to go the next day.
Because of the space used to build the new bridge they could do it quickly without closing lanes, working around traffic, etc, and could do it while they were demoing the old bridge.
NYSDOT often does this downstate. They've had a few rapid projects on the Hutch relatively recently.