I worked for Wabtec (what started out way back in the day as Westinghouse Air Brake)
I live just outside a town that changed its name to Carnegie, so he would put his railyard here.
I am not a guru on trains but I am not ignorant of them either. Yes, light rail is a bit different, but rail is designed and built for heavy duty long term use.
With proper maintenance and occassional refurbishment, 50 years for a rail frame is not atypical. Yes, you can’t just ignore it for 50 years, but properly maintained, 50 years is not outrageous at all.
I'm very familiar with Westinghouse's contribution to the transportation industry. Westinghouse sold WABCO (Ansaldo) and the people mover division long ago before it became ABC and sold most of the old industrial divisions. AFAIK, Ansaldo still operates in the Pittsburgh area. The people mover division went through a couple changes of ownership. Last I heard it belonged to Bombardier's Adtranz group which is also located near Pittsburgh.