| PRR R1 | |
| Powertype: | Electric |
| Uicclass: | 2'Do2' |
| Aarwheels: | 2-D-2 |
| Builder: | Baldwin-Westinghouse |
| Serialnumber: | BLW: 61817 |
| Builddate: | 1934 |
| Totalproduction: | 1 |
| Leadingdiameter: | 363NaN3[1] |
| Driverdiameter: | 623NaN3 |
| Wheelbase: | 54feet |
| Length: | 64feet |
| Width: | 10feet |
| Height: | 15feet over locked-down pantographs |
| Axleload: | 57500sigfig=4NaNsigfig=4 |
| Weightondrivers: | 230000sigfig=4NaNsigfig=4 |
| Locoweight: | 402000sigfig=4NaNsigfig=4 |
| Electricsystem: | 11 kV AC @ 25 Hz |
| Collectionmethod: | Pantograph |
| Tractionmotors: | Westinghouse, 625hp, eight off |
| Fuelcap: | 487usgal (for train heat boiler) |
| Watercap: | 2041usgal (for train heat boiler) |
| Maxspeed: | 100mph |
| Poweroutput: | 5000hp |
| Tractiveeffort: | 187501NaN1 at 100mph |
| Fleetnumbers: | 4800, later 4899, later 4999 |
| Retiredate: | 1959 |
| Scrapdate: | 1959 |
The Pennsylvania Railroad's class R1 comprised a single prototype electric locomotive constructed in 1934 by the Baldwin Locomotive Works of Philadelphia, Pennsylvania, US, with the electrical equipment by Westinghouse.
It was built as a competitor to the GG1 design, but after trials the GG1 was selected for volume production on the basis of its superior tracking and riding qualities; the R1 prototype, however, remained in service. It was numbered 4800 originally, swapped numbers with the victorious GG1 prototype to #4899, but was moved in May 1940 to #4999 to make room for the expanding GG1 fleet.[2]
For many years, the R1's regular duties involved hauling the westbound Broadway Limited and returning eastward with a mail and express train. The long rigid wheelbase of the locomotive caused occasional derailments in Sunnyside Yard and elsewhere.
The R1 design had four driven axles in a rigid locomotive frame, like a steam locomotive. Each was driven by two 625hp traction motors driving the wheels through a quill drive and sprung cups. Each end of the double-ended locomotive has a four-wheel truck to guide the locomotive at speed, giving the R1 a 4-8-4 wheel arrangement in the Whyte notation (AAR: 2-D-2; UIC: 2'Do2'). Besides the R1, the PRR did not build or order any other 4-8-4 locomotives, however the T1 duplex was essentially a 4-8-4 with two sets of driving wheels as a 4-4-4-4. In many respects the design resembled the earlier, lighter P5, but with an extra driving axle and lower axle loads.
