Pennsylvania Railroad Class FF1

Pennsylvania Railroad Class FF1
The sole PRR FF1, nicknamed Big Liz.
Technical specifications
Manufacturer(s)	Altoona Works, Westinghouse Electric
Type of locomotive	Electric locomotive
Constructed	1917
Number built	1 car
Classification	1-C+C-1
Dimensions	918 in (23,320 mm) × Unknown × 176 in (4,470 mm)
Gauge	4 ft 8½ in (1,435 mm)
Power supply	Pantograph
Electric system(s)	11 kV AC (25 Hz)
Service information
In service	1917 – 1940
Formation	Single car
Number in service	None
Fleet numbers	3931
Preservation information
Preserved	None
Number scrapped	1 car

The PRR FF1 was an American 1-C+C-1 electric locomotive. A sole prototype was built and named Big Liz. It was built in 1917, and the PRR intended to use it for freight over the Allegheny Mountains. Big Liz had a 1-C+C-1 wheel arrangement in the two half-frames. Big Liz proved workable, but too powerful for the freight cars of the time, with its 4,600 available horsepower and astonishing 140,000 LB/F of tractive effort. The coupler would snap whenever Big Liz pulled a train. When acting as a pusher engine, it would throw the cars off the tracks, causing a derailment.

As she was regarded as being far too powerful for service, she was sidelined and cut up in 1940.

Specifications

Construction of the FF1 was most likely of steel. The FF1's four traction motors were Westinghouse Model 451 three-phase motors each producing a rather astonishing 1,910 HP (1,424 kW) each; this gave it a total combined horsepower rating of 7,640 HP (5,700 kW), although the converters could only supply 4,600 HP (3,400 kW) for short-term usage or 4,000 HP (3,000 kW) for continuous usage. There was no way to control the speed of the FF1 due to its use of three-phase motors, with only two speed options available.

The FF1's transmission was a rotary converter which supplied a three-phase 25 Hz AC current fed to the traction motors, allowing it to run at one or two speeds. The traction motors in turn drive the jackshafts and siderods and the driving wheels themselves.

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