The Pennsylvania Railroad (PRR) class T1 duplex-drive 4-4-4-4 steam locomotives, introduced in 1942 with two prototypes and later in 1945-1946 with 50 production examples, were the last steam locomotives built for the PRR and arguably its most controversial.

Feb 2, 2018 · The Pennsylvania Railroad’s T1 duplex steam locomotive is perhaps the most eye-catching, and the most controversial ever created. Engineers at the Pennsylvania Railroad (PRR) and at Baldwin Locomotive Works created a quite complex solution to building a reciprocating steam locomotive with enormous power and the ability to cruise at 100mph.

Jun 20, 2020 · The PRR T1 was a duplex locomotive that utilized a 4-4-4-4 wheel arrangement and was designed to haul 880 trailing tons (798-t) at 100 mph (161 km/h). PRR envisioned using the engines to haul express passenger trains on the 713-mile (1,147-km) route between Harrisburg, Pennsylvania and Chicago, Illinois.

All scrapped, new build under construction. None. The Pennsylvania Railroad 'Duplex-Drive' Class T1 were a class of 4-4-4-4 tender steam locomotives equipped with Duplex-Drive, they were a real attempt along with the K5 Pacifics to replace the aging K4 Pacifics.

PRR T1 #5547 is one of fifty production Locomotives of the T1-class 4-4-4-4 Duplex built at the Baldwin Locomotive Works. It was the test bed for the PRR's experiment of attaching Walschaerts valve gear to a T1 in order to improve the locomotive's performance. It was …

PRR T-1 DUPLEX 4-4-4-4 Locomotives of the 4-4-4-4 type represented advanced mechanical engineering concepts of the very popular 4-8-4. Both wheel arrangements were similar, but testing showed that doubling up on cylinders and machinery produced great benefits to railway travel. This new development was to be dubbed "duplex".

Jul 25, 2018 · There is some evidence that PRR had solved, in principle, most of the operating issues with the T1 in 1948 (this being the Franklin type A poppet version, not wholesale conversion to T1a) including changes to the valves and seats to make them more resistant to damage at the higher ‘debounce’ closing pressure.

The PRR T1 was a duplex locomotive that utilized a 4-4-4-4 wheel arrangement and was designed to haul 880 trailing tons (798-t) at 100 mph (161 km/h). PRR envisioned using the engines to haul express passenger trains on the 713-mile (1,147-km) route between Harrisburg, Pennsylvania and Chicago, Illinois.

When the construction of passenger steam locomotives was possible again after the end of the Second World War, the PRR ordered 50 production machines without boosters. They were significantly more suitable for everyday use than the S1 …

While the electric GG1 locomotive filled the need very nicely for those tracks which were electrified, a steam locomotive was required for those long, mid-west runs. (There was no PRR electrification west of Harrisburg, PA.) The T1, a duplex-drive 4 …