[PRCo] Butterfly windows on PCCs.

[Fred Schneider]

I often wonder how many of these terms originate with railfans ... things
that the industry may never have or seldom have used ... such as Birney
car (the industry called them safety cars).  And the safety features went
back to an earlier effort between Bosenbury of Illinois Traction and
Westinghouse Air Brake.

Maybe someone who like to tell me what butterfly windows are?   I only
wrote the book.

Boris Cefer wrote:

> A>