The equipment needed to cast this beam is quite substantial oh, it can’t be cast on site.
Was wondering that myself, but moving, much less lifting a 200’ concrete beam into place would seem like a difficult proposition too.
I always wondered what the machine looked like that they used to stress the huge bundles of tendon cables we did on the bridges, after I watching them do single cables for the house foundations and 2 guys did that with a big specialty hand held hydraulic jack to tension each of the half inch diameter cables to over 30,000 pounds of force.
Not arguing your point though... Article does not mention by name but I think these are AASHTO Girders, as the article says pre-stressed, not post tensioned...
FYI for anybody following along that does not know -
Pre-stressed, the cables are stressed first, and ran through the form work of the beam, then the concrete is poured, let set up and then the tension is released...
Post-Tension concrete, the cables are stressed after the concrete reaches some specific design strength.