PRR DD2
Encyclopedia
The Pennsylvania Railroad
's class DD2 electric locomotive
was a single prototype locomotive never placed into series production.
It was intended as an improved and simplified GG1
for use on the planned, but never built, extension of the PRR's electrification west of Harrisburg, Pennsylvania
.
The one locomotive produced was numbered #5800 and used in regular service until it was scrapped in September 1962.
, as well as electrical suppliers General Electric
and Westinghouse
, and the transportation engineering firm Gibbs & Hill, who were consultants on the proposal to extend electrification to Pittsburgh
. The locomotive being designed was what became the DD2.
was 4-4-0+0-4-4 in the Whyte notation
, or 2-B+B-2 in the AAR
's system.
It had two frames, hinged together in the middle, with the driving wheels and motors mounted directly to each frame, two pairs per side. A swinging four-wheeled, unpowered truck
was mounted at the outer end of each frame. The bodywork, mounted above, swivelled on mounts on each of the two main frames. This was an identical layout to the better-known GG1
electric locomotives, but with four driven axles instead of six. Each driven wheel had two electric motors, each rated at 625 hp, giving a total rating of 5,000 hp for the locomotive.
Although it had fewer driven wheels than the GG1, the total power output was slightly greater, thanks to newer and more powerful motors. Weight on the driven wheels was approximately 286,000 lb.,
compared to the GG1's 300,000 lb, meaning that in similar conditions of adhesion the GG1 was slightly at an advantage in terms of applying power to the rail, but the difference was not great. Styling was also similar to the GG1's.
Pennsylvania Railroad
The Pennsylvania Railroad was an American Class I railroad, founded in 1846. Commonly referred to as the "Pennsy", the PRR was headquartered in Philadelphia, Pennsylvania....
's class DD2 electric locomotive
Electric locomotive
An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or an on-board energy storage device...
was a single prototype locomotive never placed into series production.
It was intended as an improved and simplified GG1
PRR GG1
The PRR GG1 is a class of electric locomotives that was built for the Pennsylvania Railroad for use in the northeastern United States. A total of 140 GG1s were constructed by its designer General Electric and the Pennsylvania's Altoona Works from 1934 to 1943....
for use on the planned, but never built, extension of the PRR's electrification west of Harrisburg, Pennsylvania
Harrisburg, Pennsylvania
Harrisburg is the capital of Pennsylvania. As of the 2010 census, the city had a population of 49,528, making it the ninth largest city in Pennsylvania...
.
The one locomotive produced was numbered #5800 and used in regular service until it was scrapped in September 1962.
Design, construction and testing
On May 21, 1937, a meeting was held in Philadelphia to outline the design of a new electric freight locomotive. The meeting was attended by the PRR and BaldwinBaldwin Locomotive Works
The Baldwin Locomotive Works was an American builder of railroad locomotives. It was located in Philadelphia, Pennsylvania, originally, and later in nearby Eddystone, Pennsylvania. Although the company was very successful as a producer of steam locomotives, its transition to the production of...
, as well as electrical suppliers General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...
and Westinghouse
Westinghouse Electric (1886)
Westinghouse Electric was an American manufacturing company. It was founded in 1886 as Westinghouse Electric Company and later renamed Westinghouse Electric Corporation by George Westinghouse. The company purchased CBS in 1995 and became CBS Corporation in 1997...
, and the transportation engineering firm Gibbs & Hill, who were consultants on the proposal to extend electrification to Pittsburgh
Pittsburgh, Pennsylvania
Pittsburgh is the second-largest city in the US Commonwealth of Pennsylvania and the county seat of Allegheny County. Regionally, it anchors the largest urban area of Appalachia and the Ohio River Valley, and nationally, it is the 22nd-largest urban area in the United States...
. The locomotive being designed was what became the DD2.
Technical details
Although the design specified either passenger gearing or freight gearing, the prototype was only ever used with freight gearing. Its wheel arrangementWheel arrangement
In rail transport, a wheel arrangement is a system of classifying the way in which wheels are distributed beneath a locomotive.. Several notations exist to describe the wheel assemblies of a locomotive by type, position, and connections, with the adopted notations varying by country...
was 4-4-0+0-4-4 in the Whyte notation
Whyte notation
The Whyte notation for classifying steam locomotives by wheel arrangement was devised by Frederick Methvan Whyte and came into use in the early twentieth century encouraged by an editorial in American Engineer and Railroad Journal...
, or 2-B+B-2 in the AAR
Association of American Railroads
The Association of American Railroads is an industry trade group representing primarily the major freight railroads of North America . Amtrak and some regional commuter railroads are also members...
's system.
It had two frames, hinged together in the middle, with the driving wheels and motors mounted directly to each frame, two pairs per side. A swinging four-wheeled, unpowered truck
Bogie
A bogie is a wheeled wagon or trolley. In mechanics terms, a bogie is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed in place, as on a cargo truck, mounted on a swivel, as on a railway carriage/car or locomotive, or sprung as in the suspension of a caterpillar...
was mounted at the outer end of each frame. The bodywork, mounted above, swivelled on mounts on each of the two main frames. This was an identical layout to the better-known GG1
PRR GG1
The PRR GG1 is a class of electric locomotives that was built for the Pennsylvania Railroad for use in the northeastern United States. A total of 140 GG1s were constructed by its designer General Electric and the Pennsylvania's Altoona Works from 1934 to 1943....
electric locomotives, but with four driven axles instead of six. Each driven wheel had two electric motors, each rated at 625 hp, giving a total rating of 5,000 hp for the locomotive.
Although it had fewer driven wheels than the GG1, the total power output was slightly greater, thanks to newer and more powerful motors. Weight on the driven wheels was approximately 286,000 lb.,
compared to the GG1's 300,000 lb, meaning that in similar conditions of adhesion the GG1 was slightly at an advantage in terms of applying power to the rail, but the difference was not great. Styling was also similar to the GG1's.