That would be the Plasser & Theurer SVM1000 new-track construction machine.[1]
Incidentally, Caltrain is now up to high-speed rail standards except for grade crossing elimination. All welded rail on concrete ties, 25KV electrification, and the new commuter trains are capable of 125MPH, although they are not run that fast.
Incidentally, Caltrain is now up to high-speed rail standards except for grade crossing elimination. All welded rail on concrete ties, 25KV electrification, and the new commuter trains are capable of 125MPH, although they are not run that fast.
[1] https://youtu.be/XwiNaHmOscU?t=400