Why Did the Duplex Steam Engine Fail?

THE PENNSYLVANIA'S FUTURE-SHAPED STEAM ENGINE THAT LOST TO A BUDGET The Pennsylvania Railroad's duplex looked like the future: a long, shark-nosed steel locomotive built to run faster than any normal steam engine and spare the track while doing it. Yet every T1 was scrapped by about 1956, and not one was saved. Was it too fast, or was the real answer something different? This documentary explains the duplex idea of splitting the work across two sets of cylinders on one frame to cure hammer blow and wheel slip, then follows it from the S1 Big Engine of 1939 to the production T1 with its tall drivers and Franklin poppet valves. We look at the wheelslip habit, the maintenance bill, and the arrival of EMD diesels that made the case for fixing steam grow weaker, and we close with the T1 Trust's effort to build a brand-new number 5550. IN THIS VIDEO The hammer blow and wheel slip problems the duplex was meant to cure The S1 Big Engine, Raymond Loewy's styling, and the 1939 World's Fair The T1: four-four-four-four wheels, 80-inch drivers and poppet valves Why wheelslip gave the T1 a reputation Why two engines and delicate valves meant constant upkeep How EMD E units and F units changed the Pennsylvania's math The T1 Trust building number 5550 from scratch CHAPTERS 0:00 Intro 1:06 The Hammer Blow Problem 2:29 The S1 Big Engine 3:46 Building the T1 5:42 Wheelslip Troubles 6:57 Maintenance Headaches 7:58 The Diesel Takeover 11:58 Rebuilding the T1 Which lost steam locomotive would you most like to see running again? Tell us in the comments. Subscribe for more railroad engineering explained. #DuplexLocomotive #PennsylvaniaRailroad #T1 #SteamLocomotive #SteamVsDiesel #SteamTrain #RailroadHistory #RailroadEngineering #Locomotive #Trains