[N&W] N&W Alco question

[nw-mailing-list at nwhs.org]

     Did Alco ever send any of their demonstrator diesels to the N&W? I
have seen photos of demo RS-11's, a RSD-4, RS-27's, C-628's, C636's, and
a C415. None of them on N&W tracks though. Also, did the N&W test any
diesels before buying their first RS-3's and GP9's? I seem to remember
reading in Trains about EMD sending a A-B-B-A set of F7 diesel
locomotives to the N&W in the early 1950's. Thank you for your help.
     Al Seever