PRR P5
Encyclopedia
The Pennsylvania Railroad
's class P5 comprised 92 mixed-traffic electric locomotive
s constructed 1931–1935 by the PRR, Westinghouse
and General Electric
.
Although the original intention was that they work many passenger trains, the success of the GG1
locomotives meant that the P5 class were mostly used on freight. A single survivor, prototype #4700, is at the Museum of Transportation
in St Louis, Missouri.
They had a wheel arrangement
of 4-6-4
in the Whyte notation
, or 2'Co2' in the UIC classification
system — three pairs of driven wheels rigidly mounted to the locomotive, with a two-axle unpowered truck
at each end.
The first P5s were built with box cabs
. A grade crossing accident in which the crew were killed led to the substitution of a streamlined steeple type cab in later production, a design which was also applied to the GG1.
When the GG1s were put in passenger service, the P5s were regeared and used in freight service for many years. The last of the class was withdrawn from service in April 1965.
lengthened by adding another pair of driving wheels; while the O1 was an "electric Atlantic" equivalent to the E6s
steam locomotive, the P5 was an "electric Pacific" designed to match or better the performance of the PRR's ubiquitous K4s Pacifics
.
These prototypes had electrical equipment from both Westinghouse and General Electric; the design was by both companies and the PRR's electrical department, and the equipment from either manufacturer was identical.
facility, still a locomotive assembly plant today, while final assembly for the Westinghouse order was subcontracted to the Baldwin Locomotive Works
(BLW).
", raised higher, with narrower-topped, streamlined "noses" to the locomotive to enable the crew to see forward. This design was carried forward to the GG1
, R1
, and DD2
designs.
The final 28 locomotives were built to this design, which was not given a separate class designation since it was mechanically and electrically identical; they were called class P5a (modified), and colloquially Modifieds.
Visually, class P5b could be distinguished from a boxcab P5a by having a lower row of ventilation grilles on the sides of the superstructure, and by having outside brake cylinders on the trucks.
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 P5 comprised 92 mixed-traffic 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...
s constructed 1931–1935 by the PRR, 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 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...
.
Although the original intention was that they work many passenger trains, the success of the 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....
locomotives meant that the P5 class were mostly used on freight. A single survivor, prototype #4700, is at the Museum of Transportation
Museum of Transportation
The Museum of Transportation of the St. Louis County, Missouri, United States Parks Department is a museum located in the Greater St. Louis area. It was first founded in 1944 by a group of individuals dedicated to preserving the past and has a wide variety of vehicles from American history...
in St Louis, Missouri.
They had a wheel arrangement
Wheel 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...
of 4-6-4
4-6-4
Under the Whyte notation for the classification of steam locomotives, 4-6-4 represents the wheel arrangement of four leading wheels on two axles , six powered and coupled driving wheels on three axles, and four trailing wheels on two axles .Other equivalent classifications are:UIC classification:...
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'Co2' in the UIC classification
UIC classification
The UIC classification of locomotive axle arrangements describes the wheel arrangement of locomotives, multiple units and trams. It is set out in the International Union of Railways "Leaflet 650 - Standard designation of axle arrangement on locomotives and multiple-unit sets". It is used in much...
system — three pairs of driven wheels rigidly mounted to the locomotive, with a two-axle 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...
at each end.
The first P5s were built with box cabs
Boxcab
A boxcab, in railroad terminology, is a locomotive in which the machinery and crew areas are enclosed in a box-like superstructure . It is a term mostly used in North America while in Victoria , such locomotives have been nicknamed "butterboxes"...
. A grade crossing accident in which the crew were killed led to the substitution of a streamlined steeple type cab in later production, a design which was also applied to the GG1.
| Year | Builder | Bodystyle | Road numbers | Notes |
|---|---|---|---|---|
| 1931 | Altoona | Boxcab | 7898 | Renumbered 4700 in 1933 |
| 1931 | Altoona | Boxcab | 7899 | Renumbered 4791 in 1933 |
| 1932 | Westinghouse | Boxcab | 4701–4742 | 4702 rebuilt to P5b in 1937 |
| 1932 | GE | Boxcab | 4755–4774 | 4770 rebuilt as Modified in 1945 |
| 1934–1935 | Westinghouse | Modified | 4743–4754 | |
| 1935 | Altoona | Modified | 4775–4790 | |
When the GG1s were put in passenger service, the P5s were regeared and used in freight service for many years. The last of the class was withdrawn from service in April 1965.
P5 prototypes
Two prototype locomotives were outshopped from the PRR's Altoona Works in 1931. They were essentially the PRR's 2-B-2 O1 designPRR O1
The Pennsylvania Railroad's class O1 comprised eight experimental boxcab electric locomotivesbuilt in 1930 and 1931.They had the wheel arrangement classified as 4-4-4 in the Whyte notation . Although successful, they were not powerful enough for the railroad's increasingly heavy trains...
lengthened by adding another pair of driving wheels; while the O1 was an "electric Atlantic" equivalent to the E6s
PRR E6
Class E6 on the Pennsylvania Railroad was the final type of 4-4-2 "Atlantic" locomotive built by the railroad, and second only to the Milwaukee Road's streamlined class A in size, speed and power. Although quickly ceding the crack trains to the larger K4s Pacifics, the E6 remained a popular...
steam locomotive, the P5 was an "electric Pacific" designed to match or better the performance of the PRR's ubiquitous K4s Pacifics
PRR K4s
The Pennsylvania Railroad's K4s 4-6-2 "Pacific" was their premier passenger-hauling steam locomotive from 1914 through the end of steam on the PRR in 1957....
.
These prototypes had electrical equipment from both Westinghouse and General Electric; the design was by both companies and the PRR's electrical department, and the equipment from either manufacturer was identical.
P5a production locomotives
As tests proved the P5 design sound, unsurprisingly since it was an evolution of previous practice, orders were placed for 90 production locomotives, classified P5a due to minor changes from the prototypes (most notably, larger traction motor blowers). Production was split largely between General Electric and Westinghouse; the GE examples were assembled at GE's Erie, PennsylvaniaErie, Pennsylvania
Erie is a city located in northwestern Pennsylvania in the United States. Named for the lake and the Native American tribe that resided along its southern shore, Erie is the state's fourth-largest city , with a population of 102,000...
facility, still a locomotive assembly plant today, while final assembly for the Westinghouse order was subcontracted to the Baldwin Locomotive Works
Baldwin 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...
(BLW).
P5a (modified) steeplecabs
A fatal grade crossing accident on the New York Division confirmed traincrews' concerns about safety when the crew were killed after colliding with a truckload of apples. A redesign was undertaken, giving the locomotives a central "steeple cabSteeplecab
In railroad terminology, a steeplecab is a style or design of electric locomotive; the term is rarely if ever used for other forms of power...
", raised higher, with narrower-topped, streamlined "noses" to the locomotive to enable the crew to see forward. This design was carried forward to the 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....
, R1
PRR R1
The Pennsylvania Railroad's class R1 comprised a single prototype electric locomotive constructed in 1934 by the Baldwin Locomotive Works of Philadelphia, Pennsylvania, USA, with the electrical equipment by Westinghouse....
, and DD2
PRR DD2
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...
designs.
The final 28 locomotives were built to this design, which was not given a separate class designation since it was mechanically and electrically identical; they were called class P5a (modified), and colloquially Modifieds.
P5b experiment
In October 1937 P5a #4702 was rebuilt with motors in its trucks to become the only locomotive in subclass P5b. Each truck axle was given a 375 hp motor, adding 1500 hp to give a total power output of 5350 hp. This modification also meant that locomotive's entire weight was carried on driven wheels. Despite these advantages, the experiment was not repeated; #4702 continued in its modified form, however. Staufer & Pennypacker in Pennsy Power state that the experiment was less than successful due to problems in cooling the motors in the trucks.Visually, class P5b could be distinguished from a boxcab P5a by having a lower row of ventilation grilles on the sides of the superstructure, and by having outside brake cylinders on the trucks.