Pennsylvania (PRR) - (In-Service, black, gold, graphite) - Road #5512 - T1 4-4-4-4- Locomotive with Paragon4 Sound Installed
With the goal of developing more powerful motive power for express passenger service, the Pennsylvania Railroad introduced the class T1 Duplex 4-4-4-4 in 1942 with two prototype locomotives, and followed in 1945-1946 with 50 production models. Built with striking streamlining designed by Raymond Loewy, the T1 engines were large, powerful, and fast!
The T1's were duplex locomotives - this means they had two sets of drivers, each with its own pair of cylinders and rods. However, the T1s were not articulated locomotives, but used one rigid frame. With this design, the cylinders could be smaller and the weight of side rods and main rods could be reduced. This duplex design with lighter machinery, shorter cylinder stroke, less wear and tear due to small moving parts and the use of poppet valves allowed the T1's to travel at extremely fast speeds. Unfortunately they were also prone to wheelslip and maintenance issues that the Pennsy struggled to work through - especially the fact that the poppet valves could not withstand sustained operation at 100 mph speeds. These problems likely could have been resolved with some modest design changes, but the PRR, and steam in general, ran out of time. In 1948, the PRR dieselized all of its first-class prime trains and the T1s were downgraded to haul secondary trains. Some were withdrawn from service in 1949, and all were retired by 1952.