Pennsy’s “Big Engine” in the snow By Angela Cotey | April 19, 2014 | 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’s one-of-a-kind class S1 6-4-4-6 duplex drive No. 6100 shrugs off an early Chicago winter snow storm as it pauses at Englewood Union Station with the eastbound Manhattan Limited in November 1939. Harold Stirton photo