PENNSYLVANIA RAILROAD MOTIVE POWER

BALDWIN (PRR ALTOONA WORKS JUNIATA SHOPS) M1b 4-8-2 steam locomotive

History / Profilo storico


The "Mountain" 4-8-2 was a fast dual-service steam locomotive that was bought by many railroads in need of more motive power for the ever increasing weight of passenger trains and to compete for fast freight. In North America (United States and Canada) 41 railroads bought or built 2.211 "Mountain" Locomotives. The New York Central and the Pennsylvania Railroad used a combined total of 901 or 41% of the total. The first one built was the Chesapeake & Ohio Railroad number 316 built in 1911 and the last one built was Baltimore & Ohio number 5594 in 1948.
The success of the M1 Mountain-type locomotives prompted the Pennsylvania Railroad to order 300 more locomotives of the 4-8-2 wheel arrangement in 1930, though several upgrades were incorporated in the new machines (100 class M1a/M1b from 1930). The new locomotives became the M1a class and had a longer wheelbase than the M1's due to the addition of the Worthington feedwater heater.  They also received the new larger class 210F75 tenders with 31,5 tons of capacity (coal/oil), which became known as the coast-to-coast tenders.  The first 50 M1a locomotives (6700-6749) were built by Baldwin; Juniata Shops (later known as Altoona Works) built the next 25 M1a's (6750-6774), and the remaining 25 were built by Lima and numbered 6775-6799. Some units were then improved as class M1b since 1946. The improvements were related to the boiler pressure and the addition of circulators to the firebox. PRR took over these locomotives for heavy freight and passenger haulers and then various M1 in service were used until the radiation by the service of steam locomotives in 1957.


La locomotive a vapore con rodiggio 4-8-2, denominata Mountain, era impiegata per il traino veloce di treni pesanti, sia merci che passeggeri. In Nord America (Stati Uniti e Canada) è stata acquistata da ben 41 compagnie per un totale di 2.211 esemplari costruiti. Le due principali compagnie americane operanti nell'est, la New York Central e la Pennsylvania Railroad (prima rivali ma poi unitesi nella Penn Central) impiegarono un totale di 901 locomotive di questo tipo (41% del totale cotruito). La prima unità prodotta è stata assegnata nel 1911 alla compagnia Chesapeake and Ohio, mentre l'ultima anḍ alla Baltimore and Ohio nel 1948.
Il successo di queste locomotive porṭ all'acquisizione di 301 esemplari da parte della Pennsylvania Railroad, a partire dal 1923. In seguito, dal 1930, videro la luce alcune varianti con miglioramenti soprattutto alla pressione di esercizio, in modo da aumentare la potenza di trazione. Le nuove M1a/M1b della PRR furono equipaggiate con i tender del tipo 210F75 con la capacità di carico per carbone/olio combustibile portata a 31,5 tonnellate, adatti a coprire lunghe distanze di percorrenza.
Le prime 50 unità classe M1a per la PRR furono costruite dalla Baldwin (numeri di serie da 6700 a 6749); i Juniata Shops (poi chiamati Altoona Works) produssero le successive 25 unità (6750-6774), mentre la Lima costrú le ultime (6775-6799).
Le Mountain della PRR furono impiegate intensamente fino alla radione delle locomtoive a vapore dal servizio attivo, avvenuta alla fine del 1957.

M1b Specifications / Specifiche tecniche
BuildersPRR Juniata Shops
Production1930-1948 (rebuilt type)
Total prod.201 Type M1
100 Type M1a/M1b
PRR roster301 (1923-1948)
Wheels4-8-2 (UIC 2-D-1)
Loco weight385.000 lb (no tender)
Lenght?
PowerCoal/Oil
Gauge4 ft 8,5 in 
Driver diameter76"
Cylinders2 (27 x 30 in)
Valve gearWalschaerts
Pressure270 psi
Tractive effort69.700 lbf
CostruttoriPRR Juniata Shops
Produzione1930-1948 (ammod.)
Prod. totale201 Tipo M1
100 Tipo M1a/M1b
Quantità PRR301 (1923-1948)
Rodiggio4-8-2 (UIC 2-D-1)
Peso174.600 kg (no tender)
Lunghezza?
CombustubileCarbone/Olio combustibile
Scartamento1,435 mt
Diametro
ruote motrici
1,83 mt
Cilindri2 (0,69 x 0,76 mt)
DistribuzioneWalschaerts
Pressione1,86 MPa
Potenza310,00 kn

Baldwin 4-8-2 M1b #6747 Pennsylvania Railroad


Baldwin 4-8-2 M1 #6758 Pennsylvania Railroad

Broadway Limited Imports 4-8-2 M1b Pennsylvania Railroad #6758 data / dati
Road Number:6758
Road Number Sequence:1st
Type:4-8-2
Class:M1a, M1b
Builder:Juniata
Built:1930
CN:4229
Disposition:sold for scrapped 2/58
Previous Owner: 
Remarks:rebuilt 12/48 M1b
Serial Number:12004
Assignment 1950/1954Eastern Region - Middle Division
Assignment 1956/1957Pittsburgh Division

Photogallery / Galleria immagini
  
      
Number of 4-8-2 "Mountain" Type Locomotives built by Year
Year
Railroad191112131415161718192021222324252627282930313233343536373839404142434445464748Total
AGS      2                               2
Alaska                     1         1      2
AT&SF       2101114 86                        51
AB&C                                      nonew
ACL                                      nonew
B&O              11   2           3107737344
BAR                  43    2         1   10
B&M                        5 5 3 5       18
CN            16129   98             20    74
CPR   2                                  2
CentVermont                4                     4
CentralofGA        37 25555                      32
C&O21     5    2                         10
CB&Q           8  13                       21
CRI&P  2      10  30  510 5                   62
CNO&TP      5                               5
CCC&StL                  50                   50
DL&W             552015                     45
D&RGW           1020  10                      40
FEC            15192333                      90
GTW              5                       5
GN   15        28                         43
IC            15 2520          120119151010     136
L&HR                                 3    3
LV            33                        6
L&N               16   6                  22
MStP&SSM               10 8 3                  21
MoPac  7     7 5 4   5  5                  33
NC&StL        5  2222                       13
NdeM                                      nonew
NOGN                3                     3
NYC     3016139      199  12525         401027344    550
NYNH&H        1030   9 11 10                    70
NYO&W           46     10                   20
N&W      88 10  12  10                      48
PRR            1  200   100                  301
RF&P             22                       4
Rutland                                   4  4
SL-SF            15 510         65 6665      64
SLSW                                      nonew
SAL   10  5    10 201610                      71
SP            142091455115                  83
Southern      23 25                             48
TennCentral              4                       4
T&P              5  5                    10
UP           40155                        60
Wabash                   25                  25
WP                                      nonew
WRwyofAla         2                            2
Totals:21927 3059154617019762111081304744228214182 1  76112020553646543487732211
Builders of 4-8-2 "Mountain" Type Locomotives
Railroad LineQuantity and Builder
Alaska Railroad2 Baldwin
Atchison, Topeka & Santa Fe51 Baldwin
Baltimore & Ohio2 Baldwin 42 B&O
Bangor & Aroostook10 ALCO
Boston & Maine18 Baldwin
Canadian National Railway42 CLC 32 MLW
Canadan Pacific Railway2 CPR
Central Vermont4 ALCO
Central of Georgia27 ALCO 5 Baldwin
Chesapeake & Ohio8 ALCO 2 Baldwin
Chicago, Burlington & Quincy13 BLW 8 Lima
Chicago, Rock Island & Pacific62 ALCO
Delaware, Lackawanna & Western45 ALCO
Denver & Rio Grande Western30 ALCO 10 Baldwin
Florida East Coast90 ALCO
Grand Trunk Western5 Baldwin
Great Northern28 Baldwin 15 LIMA
Illinois Central35 ALCO 25 LIMA 76 IC
Lehigh & Hudson River3 Baldwin
Lehigh Valley6 ALCO
Louisville & Nashville22 Baldwin
Minneapolis, St. Paul & Sault Sainte Marie18 ALCO 3 Soo
Missouri Pacific33 ALCO
Nashville, Chattanooga & St. Louis5 ALCO 8 Baldwin
New Orleans Great Northern3 ALCO
New York Central435 ALCO 165 Lima
New York, New Haven & Hartford70 ALCO
New York, Ontario & Western20 ALCO
Norfolk & Western10 ALCO 12 Baldwin 26 N&W
Pennsylvania225 Baldwin 50 LIMA 26 PRR
Richmond, Fredericksburg & Potomac4 ALCO
Rutland4 ALCO
St. Louis - San Francisco30 Baldwin 34 SLSF
Seaboard Air Line25 ALCO 36 Baldwin
Southern Pacific34 ALCO 49 SP
Southern58 Baldwin
Tennessee Central4 ALCO
Texas & Pacific5 ALCO 5 Baldwin
Union Pacific60 ALCO
Wabash25 Baldwin
Western Pacific10 ex FEC
Western Railway of Alabama2 ALCO

This data are courtesy of www.steamlocomotive.com by Richard Duley.
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