It’s by perusing the HO Brass section of EBay that I came upon the Pennsy’s FF1 and L5. They remind me of old Swiss mountain locomotives. There seems to be little information on both of these types. Can anyone provide some historical background on these units, or recommend some books/websites that would be of interest. How long did these locomotives remain in service? I read that the sole FF1 spent most of its life in a yard.
The FF-1's principal problem was that the operation it was designed for failed to materialize. The PRR built a single FF-1 (#3931) as an experimental prototype in 1917, at a time when it was seriously considering electrification over the Alleghenies. The 4,000 hp, 250-ton monster was designed strictly for heavy lugging service between Altoona and Johnstown. (PRR employees universally called it "Big Liz.") Among other things it had a split-phase electrical system with constant-speed motors that ran at either 10.4 or 20.8 mph, considered good for the intended service but not for much else. The simultaneously developed I-1 2-10-0 steam design was considered a more immediate, practical, and economical solution to the Allegheny grade problem, and, the electrification was "temporarily" shelved. Not suited for much else, the FF-1 spent its working life as a freight pusher on the 1% WB grade between Philadelphia and Paoli, and was finally scrapped in 1940.
The Allegheny electrification idea briefly resurfaced in 1923, and in 1924 the PRR attempted to improve on the FF-1 concept by building three L5 1-D-1 3,000 hp 200-ton electrics. (Although not articulated, the L5s actually were 1-B-B-1s, since the running gear consisted of two pairs of separately-driven drivers.) This design was intended as a "universal" locomotive, suitable for both passenger service in the East and for the revived Allegheny electrification proposal. Thus the first of the three (#3930) was built as an 11,000-volt a.c. unit; the other two (#3928-3929) were third-rail 600=volt d.c. for the New York-Manhattan Transfer operation to supplement and eventually replace the DD-1s. Like the FF-1, the a.c. #3930 went into Phila.-Paoli helper service and also showed up in Baltimore in helper service on the nasty WB grade through the B&P tunnels through West Baltimore. It was scrapped in 1944.
Although not a particularly successful design by later standards, 21 more d.c. L5s were built between 1926-28 to relieve pressure on the the DD-1s, and to allow some DD-1s to be shifted to the Long Island R. R. These were numbered 3922-3927 and 7801-7815, and were finally scrapped in 1942 along with the original #3928-29. It's a bit surprising that they were kept this long after the a.c. electrification was completed in 1935, but the thinking always was that they would eventually be converted for a.c. operation when the time came. (Given the number that were in service in New York between 1927 and 1935, it's also surprising that so few photos exist of them working in this operation.)