Pennsy’s “Big Engine” in the snow By Mitch Horner | November 5, 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 Share this article Print Facebook