Pennsylvania 2-8-2 "Mikado" Locomotives in the USA

The Pennsylvania Railroad built a fleet of 574 "Mikado" type locomotives between 1914 and 1919. It was the largest single class of Mikados. This group was designated as Class L1 and was assigned numbers scattered from 2 through 9866.

In 1913, J. T. Wallis, who was the Superintendent of Motive Power for Lines East together with two of the railroad's mechanical engineers, Alfred Gibbs and Axel Vogt, came up with an idea for using some of the same parts for a badly needed Class L1 "Mikado" type freight hauler and it new Class K-4 "Pacific" type passenger locomotive. The two locomotive designs used identical boilers and the same Belpaire firebox as well as many other mechanical parts. There were 425 of the Class K-4 "Pacific", which meant the PRR had 999 almost identical locomotives.

The Class L1 "Mikados" were built in the Juniata Shops in Altoona, PA and by the Baldwin Locomotive Works and the Lima Locomotive Works. The Juniata shops built 344, Baldwin built 205 and Lima built 25.

Starting tractive effort was 61,465 lbs. This was the equal of any built in its time period, although the lack of a stoker as original equipment was a minus. Yet, its service record was not truly what one might have expected. For one thing, the mighty I1s and I1sa 2-10-0, which replaced the L1s in coal hauling and Pittsburgh Division service, followed it into service very closely. Then, the M1s took away a large part of the low grade fast freight traffic. Finally, in the 1930s, the electrification of freight traffic between New York and Potomac Yard and later, Enola, combined with the tremendous loss of business during the Depression period placed hundreds of these 2-8-2s in storage until wartime demands brought them back onto the road. Some were still hand fired, and some were sold to other roads: the Santa Fe and the Lehigh & New England.

There is one surviving PRR Class L1 2-8-2 locomotive. It is number 520 that is now on display at the Railroad Museum of Pennsylvania in Strasburg, PA.


Roster by Richard Duley

ClassQty.Road NumbersYear BuiltBuilderNotes
L15742 ... 98661914-1919PRR, Baldwin & Lima1
L259627-96311919ALCO1,2
Notes
  1. See Chart for road numbers
  2. USRA allocated "Mikado-Light" locomotives.

Class L1 and Class L2 Road Numbers
ClassQty. Road NumbersYear BuiltBuilderNotes
L13114266426489710112811751337140414661914PRR#266 sold to Int. in 1948
20336647649678011291191134114521547
207385480559112711721235134414641579
1752
1231140561511651335148315781782327834971915PRR#1315 sold to LNE in 1941
264106401169134914891580179032803498 #734 sold to C&I in 1941
294246581192135314911582179932813499
394637181241135415071584275932823543
715107341264135815091590297332833609
755357621268136015111596315932844030
1035378531269136615201614316034874069
1205488601283136915281627327234884094
2705529341299137815431685327334894111
31855410281315138615451715327434904112
38856710741318138915721716327534944126
39958711411334144315741768327634954149
327734964152
52724477149241272136814781523158116711916PRR#190 sold to LNE in 1941
137469742931127513831486152915951712 #1642 sold to DT&I in 1948
190546831932128614421498153716121732
2165979031014133814551513154816171797
3706869231143136514721514157016423227
16433231
12622115006511173134316263491363936521916Baldwin#520 put on display in 1957
46242512703118213481632354636403653 #1388 sold to C&I in 1941
64252513729118313521747360736417025 #3642 sold to DT&I in 1948
67254514738118613571784362936427086 #1626 sold to Int. in 1948
110258520776119713641786363036437150 #7025 converted to oil burner in 1940s
126259533786124013851791363136447227 #7248 converted to oil burner in 1940s
135283578843124213881792363236457243
138289604906128214442099363336467245
185342618977130414472730363436477246
2003626331138130614683464363536487247
2053986351140130714713474363636497248
2064316501171131915343477363736507259
134216253483363836517261

Class L1 and Class L2 Road Numbers (Continued)
ClassQty. Road NumbersYear BuiltBuilderNotes
9422121275555804115917233089621062921917PRR#4185 sold to ATSF in 1945
4017127660880613901741329462386295
5618028063080914121788351862486296
6919630563181814271860360062536297
8821035668784414282358360362556298
9322140773192116352369416262646299
10122444978192516382526417462656306
111241468783101716502745418562696308
117267473801113716512911418862706309
3053620562726312
49840935117413931662276040284190769797041917Baldwin#4031 sold to ATSF in 1945
86893811941467168232264031734092179705 #7342 sold to ATSF in 1945
87893913201487168432294072734292299721 #7637, 9356 & 9704 converted to
89094113761656169732304082763793539722 oil burners in late 1940s
105913801657175535124130765093569730
2570087128722872427331734574837638936598601917Lima#7220, 7228, 7232, 7249, 7344, 7628,
7117722072327249734474187613764697529861 7638 9235, 9860 & 9866 converted
74817628923597539866 to oil burners in late 1940s
44174603657793969137414491542163317191918PRR#1719 sold to LNE in 1941
42060567495097813751454155616391778
556611682951112213911463158516721828
577637791952116414291474159816953236
1518160317183408
178761372196719711975198622712461268228611918Baldwin#1986 sold to LNE in 1941
1972198222532359267127572937
1329432963307630783579358135833585358735891919Baldwin
358635883590
L2596279628962996309631 1919ALCOUSRA allocated locomotives

Class Details by Steve Llanso of Sweat House Media

Class L1s (Locobase 32)

Data confirmed by table in May 1916 issue of Railway Mechanical Engineer. See also DeGolyer, Vol 51, pp. 171+; Issue 28, Locomotive testing plant at Altoona, Pa: Bulletin, 1914 and John W Orr, Set Up Running : the Life of a Pennsylvania Railroad Engineman, 1904-1949 (Pennsylvania State University Press, 2001), p. 125 and DeGolyer, Vol 59, pp. 275+.

Another one of the Pennsy's classes built in heroic numbers over five years; among all American 2-8-2s only the US Railroad Administration's Light Mikados (Locobase 40) were built in greater numbers to a single design for a non-Governmental railroad.

These Mikes used the same Belpaire boiler design as did the famous K-4s Pacifics (Locobase 159) and the class gave the same long service. Perhaps surprisingly, the piston valves had a relatively modest 12" (305 mm) diameter. Firebox heating surface area included the 62 sq ft (5.75 sq m) in the combustion chamber and 34.6 sq ft (3.2 sq m) of arch tubes.

The test bulletin acknowledged that the tubes were relatively short, but reported that the length was a "direct result of trials in which it developed that free steaming can be secured only by a tube of moderate length and one having a certain ratio of length to diameter."

Juniata produced the lion's share -- 344 -- with Baldwin adding 205, and Lima 25. Most went to Lines East with only 50 serving west of the Appalachians.

John Orr's father quoted a long-time engineer--O.P.-- as claiming in the mid-1920s "the best all-purpose locomotive that had been developed thus far [on the Pennsy] was the L1s. It could run fast, steam easily, ride well, and, despite its rather large size for a Mikado, it was economical to operate."

On the railroad forum rec.models.railroad -- http://groups.google.com/group/rec.models.railroad/browse_thread/thread/a7363d8213934a42/098ee808e0e95dec?lnk=st&q=Great+Northern+2-6-8-0&rnum=7&hl=en#098ee808e0e95dec

Mark Newton provided an excellent outline of the difference between a Pennsy Belpaire and others:

"The Pennsy and the railroad trade journals of the time alike described the PRR designs as a modified Belpaire type. In this case the wrapper and sidesheets were typically separate, with the seam below the radius of the wrapper plate, which is larger by comparison with other Belpaire designs. Both wrapper and crown sheet have a large radius set, as

opposed to being nearly flat. The layout of the crown stays is slightly radial, as opposed to the parallel layout of a more typical Belpaire firebox. The combustion chamber was relatively lengthy, and projected well forward of the firebox sidesheets."

[Date: Thurs, Aug 21 2003 9:59 am - Email: Mark Newton marknew ...@optusnet.com.au>

Groups: rec.models.railroad]

Locobase offers the opinion that the integration of the combustion chamber into the top line of the boiler helped these engines achieve a distinctive and more elegant look (in a rivets-and-steel-plate techno art sort of way) that reached its apotheosis in the M-1 Mountains (see Locobase 220).

Specifications by Steve Llanso of Sweat House Media
ClassL1s
Locobase ID32
RailroadPennsylvania (PRR)
CountryUSA
Whyte2-8-2
Number in Class574
Road Numbers
GaugeStd
Number Built574
BuilderSeveral
Year1914
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)17.04 / 5.19
Engine Wheelbase (ft / m)36.37 / 11.09
Ratio of driving wheelbase to overall engine wheebase 0.47
Overall Wheelbase (engine & tender) (ft / m)72.25 / 22.02
Axle Loading (Maximum Weight per Axle) (lbs / kg)59,000 / 26,762
Weight on Drivers (lbs / kg)238,000 / 107,955
Engine Weight (lbs / kg)315,000 / 142,882
Tender Loaded Weight (lbs / kg)158,000 / 71,668
Total Engine and Tender Weight (lbs / kg)473,000 / 214,550
Tender Water Capacity (gals / ML)7000 / 26.52
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)12.50 / 11.40
Minimum weight of rail (calculated) (lb/yd)99
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)62 / 1575
Boiler Pressure (psi / kPa)205 / 14.10
High Pressure Cylinders (dia x stroke) (in / mm)27" x 30" / 686x762
Tractive Effort (lbs / kg)61,465 / 27880.09
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.87
Heating Ability
Firebox Area (sq ft / m2)301.50 / 28.01
Grate Area (sq ft / m2)70 / 6.51
Evaporative Heating Surface (sq ft / m2)4035 / 375
Superheating Surface (sq ft / m2)1154 / 107.25
Combined Heating Surface (sq ft / m2)5189 / 482.25
Evaporative Heating Surface/Cylinder Volume202.96
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation14,350
Same as above plus superheater percentage17,507
Same as above but substitute firebox area for grate area75,405
Power L116,972
Power MT628.85

Photos

Reference