Pennsy RS1 By Angela Cotey | March 20, 2019 | Last updated on August 8, 2025 Email Newsletter Get the newest photos, videos, stories, and more from Trains.com brands. Sign-up for email today! Get Updates The Pennsylvania owned 22 Alco RS1s, acquired 1950–51. In this late 1950s view, No. 5620 idles at South Amboy, N.J., in the company of P5a electric 4709. Don Wood photo