Pennsylvania Railroad class R1

{{Short description|American electric locomotive prototype}}

{{Infobox Locomotive

|name = PRR R1

|powertype = Electric

|image = PRR R1.jpg

|imagesize = 300px

|caption = R1 #4800 in its builders' portrait

|whytetype = {{whyte|4-8-4}}

|uicclass = 2'Do2'

|aarwheels = 2-D-2

|builder = Baldwin-Westinghouse

|serialnumber=BLW: 61817

|builddate = 1934

|totalproduction = 1

|gauge= {{Track gauge|56.5in|allk=on}}

|leadingdiameter = {{convert|36|in|m|3|abbr=on}}{{cite web |url = http://prr.railfan.net/diagrams/PRRdiagrams.html?diag=r1.gif&sel=ele&sz=sm&fr= |title = PRR R1 Diagram |author = Pennsylvania Railroad |work = PRR.Railfan.net |accessdate = 2008-08-27}}

|driverdiameter = {{convert|62|in|m|3|abbr=on}}

|wheelbase = {{convert|54|ft|0|in|m|2|abbr=on}}

|length = {{convert|64|ft|8|in|m|2|abbr=on}}

|width = {{convert|10|ft|6.19|in|m|2|abbr=on}}

|height = {{convert|15|ft|0|in|m|2|abbr=on}} over locked-down pantographs

|axleload = {{convert|57500|lb|kg t|sigfig=4|abbr=on}}

|weightondrivers = {{convert|230000|lb|kg t|sigfig=4|abbr=on}}

|locoweight = {{convert|402000|lb|kg t|sigfig=4|abbr=on}}

|electricsystem = 11 kV AC @ 25 Hz

|collectionmethod = Pantograph

|tractionmotors = Westinghouse, {{convert|625|hp|abbr=on}}, eight off

|fuelcap = {{convert|487|usgal|abbr=on}} (for train heat boiler)

|watercap = {{convert|2041|usgal|abbr=on}} (for train heat boiler)

|maxspeed = {{convert|100|mph|abbr=on}}

|poweroutput = {{convert|5000|hp|abbr=on}}

|tractiveeffort= {{convert|18750|lbf|kN|1|abbr=on}} at {{convert|100|mph|abbr=on}}

|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.{{Staufer-Pennsy}}

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.{{cite web

|url = https://www.steamlocomotive.com/GG1/r-1.shtml

|title = The Pennsylvania Railroad GG1: The R1

|work = SteamLocomotive.com

|first = Wes

|last = Barris

|accessdate = 2008-08-27

|archive-date = 2008-09-18

|archive-url = https://web.archive.org/web/20080918233336/http://www.steamlocomotive.com/GG1/r-1.shtml

|url-status = dead

}}

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 {{convert|625|hp|adj=on}} 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.