PRR AA1

Infobox Locomotive Auto
name = PRR AA1
powertype = Electric

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caption = PRR AA1 #10001

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caption2 = PRR AA1 #10002
builder = Pennsylvania Railroad Altoona Works
builderother = Westinghouse
builddate = 1905
serialnumber = EZN-7, EZN-8cite web
last = Britton
first = Jerry
title = Electric Class Cross Reference
url = http://kc.pennsyrr.com/motiveops/elec_xref.php
work = Keystone Crossings
year =
quote =
accessdate = 2008-05-03 ]
totalproduction = 2
aarwheels = B-B
wheelsize = convert|56|in|mm|abbr=on
wheelbase = Truck: convert|8.5|ft|abbr=on
Overall: convert|26|ft|abbr=on
weight = 10001: convert|87|short ton|abbr=on
10002: convert|97|short ton|abbr=on
electricsystem = 600 V DC
collectionmethod = 3railThe Pennsylvania Railroad's class AA1 comprised two experimental electric locomotives constructed in 1905 by Westinghouse at the start of the PRR's electrification project.cite book
last = Burch
first = Edward Parris
title = Electric Traction for Railway Trains
url = http://books.google.com/books?id=k3k5AAAAMAAJ
year = 1911
publisher = McGraw-Hill
location = New York
isbn =
quote = ] cite book
last = Staufer
first = Alvin F.
title = Pennsy Power
id = LOC 62-20878
year = 1962
publisher = Staufer
pages = 247] They were testbeds for larger locomotives to come. Both were of B-B wheel arrangement in the Association of American Railroads classification scheme; each had two trucks, each with two axles and four wheels.

The first, #10001, used gearless motors attached to the axles. The second, #10002, was built with motors mounted in the truck frames and geared to the wheels. Later on it was given one gearless truck.

Both locomotives proved unstable at speed, pounding the track with high lateral forces. A competing experimental unit, "Odd D" #10003, of 4-4-0 wheel arrangement in Whyte notation or 2-B in the AAR scheme, proved much more stable. It was selected as the basis for the production model, which became the PRR DD1 twin-unit locomotive.

At low speeds in switching service, however, the locomotives were acceptable. The first, #10001, was renumbered #3950 and was sold to the (PRR subsidiary) Long Island Rail Road in 1916. Numbered 323 on that road and nicknamed "Phoebe", the locomotive was in use until 1937 when it was scrapped. [cite book
last = Keller
first = David
coauthor = Steven Lynch
title = Revisiting the Long Island Rail Road
url =
year = 2005
publisher = Arcadia
location =
isbn = 0738538299
quote =
pages = 12] No. 10002, meanwhile, was renumbered #3951 and continued in service on the PRR.cite book
last = Staufer
first = Alvin F.
title = Pennsy Power II
id = LOC 62-20872
year = 1968
publisher = Staufer
pages = 124]

References