Philadelphia & Reading 4-4-2 "Atlantic" Locomotives of the USA


Class Details by Steve Llanso of Sweat House Media

Class 100 (Locobase 14994)

Data from Roy V Wright (Ed.) 1922 Locomotive Cyclopedia of American Practice, Sixth Edition (New York: Simmons-Boardman Publishing Company, 1922), p. 176.

This inspection engine originally entered service in 1903 (Locobase 12643). It was later considerably enlarged as shown in this entry. The long passenger compartment had eight seats.


Class 376 / D-10a/P-1b (Locobase 15924)

Data from DeGolyer, Volume 21, p. 172. See also Alfred Bruce (1952). (Thanks to Chris Hohl for his 25 January 2014 email correcting the driver diameter.) Works numbers were 15880-15883 in April 1898.

This class was an immediate continuation of the Atlantic City's Camelback 4-4-2s (Locobase 2562). Like those engines, this quartet ran as Vauclain compound and had the camelback layout with the wide Wootten firebox. This accounts for the deceptively low firebox/grate area ratio. Firebox heating surface included 53.8 sq ft (4.2 sq m) in the combustion chamber.


Class P-3b (Locobase 9456)

Data from RDG 11 - 1926 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. See also DeGolyer, Volume 24, p. 275. Thanks to Chris Hohl for his suggested updates that led me to the Baldwin specs. Works number was 20531 in June 1902.

The Reading built these two high-drivered Atlantics to compare simple-expansion working (Locobase 9455) with that available to a Vauclain balanced compound with even more cylinder volume. Apparently, the 329 was even less successful than any of the earlier Reading compounds as it received two 21" cylinders in 1904. At that point it was a duplicate of the 328; see Locobase 9455.


Class P1-c (Locobase 12415)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 23, p. 37. Works numbers were 7787-17788 in May 1900, 17812-17813 in June.

Part of the Vauclain compound parade that reached its peak right about the time these were ordered, these Atlantics didn't retain that system for very long. Locobase 9450 shows the results of


Class P1-e (Locobase 9449)

Data from RDG 11 - 1926 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

All four locomotives were built as Vauclain compounds (Locobase 15924). The Reading retained the large Wootten firebox in a rebuild the shops completed in 1904, but abandoned the compound cylinders and very tall 84 1/4" drivers in favor of two simple-expansion cylinders and 74" wheels.

So modified, the quartet supported fast passenger operations until the 311 was sent for scrap in February 1927 with 314 following in November. Five years later the second pair was sent to the ferro-knacker in August (312) and December (313).


Class P1-f (Locobase 9450)

Data from RDG 11 - 1926 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

As noted in Locobase 12415, express Vauclain-compound locomotives on the Reading didn't operate for long in that setup. The Reading's shops took the quartet of tall-drivered engines with this boiler and converted them in 1904. At some point, probably later in their careers, the shops eliminated 27 tubes from the tubesheet. (If it was the product of installing a new boilerr, they may sought wider tube spacing for greater strength. Or they simply may have blocked off the extra tubes.)

They served the Reading for another 25 years before the 320-321 were scrapped in July 1930. The 318-319 followed in September 1933.


Class P2-a (Locobase 9451)

Data from RDG 11 - 1926 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

These were all Reading-built express passenger engines with large Wootten fireboxes. All were rebuilt in 1913-1914; see Locobase 9452.


Class P2-b (Locobase 9452)

Data from RDG 11 - 1926 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

P-2as built in 1907, redesignated in 1914 with the most apparent difference was a 15-psi reduction and the adoption of outside radial valve gear. Weight dropped on the drivers, but increased over the lead bogie and the trailing truck.

Later reduced to 276 tubes (for 2,088.7 sq ft of tube surface vs 2,139) . Most were scrapped in the mid-1930s.


Class P3-a (Locobase 16161)

Data from DeGolyer, Volume 23, p. 38. (Thanks to Chris Hohl for his 10 December 2016 email noting the misplaced decimal in the LP stroke, which incorrectly reduced it to 2.4".) Works numbers were 17741-17742 and 17765-17768 in May 1900.

At nearly the height of the four-cylinder Vauclain compound infatuation, the Reading bought these six Atlantics. The power system took orthodox form: Each side had an HP and an LP cylinder cast together and supplied through a single relatively large 15" (381 mm) piston valve. The Reading also adopted 1 3/4" diameter tubes and a firebox with a 48" long combustion chamber contributing 61.1 sq ft (5.68 sq m) to the firebox heating surface area.

Regardless of the often breathless descriptions of the savings and performance, the railroad soon dispensed with the compound system; see Locobase 9453.


Class P3-c (Locobase 9453)

Data from RDG 11 - 1926 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works numbers were 17741-17742 and 17765-17768 in May 1900.

Only three years after the six Vauclain compound Atlantics were delivered to the Reading (Locobase 16161), the railroad simpled them and raised the boiler pressure (not a usual step).

A decade later, the Reading again reconfigured the boiler and wound up with fewer, but larger-diameter tubes resulting in much less heating surface; see Locobase 9454.


Class P3-d (Locobase 9454)

Data from RDG 11 - 1926 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Apparently the idea of squeezing a lot of relatively small-bore (1 3/4") tubes into a boiler didn't work out well in practice, so the Reading reconfigured the boiler to a more conventional layout. In the process, the engine lost about one-quarter of its heating surface.

The entire class was retired in 1933.


Class P4-a/P4-d (Locobase 9455)

Data from RDG 11 - 1926 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. See also DeGolyer, Volume 24, p. 274. Thanks to Chris Hohl for his suggested updates that led me to the Baldwin specs. Works number was 20529 in June 1902.

The Reading built these two high-drivered Atlantics to compare simple-expansion working with that available to a Vauclain balanced compound with even more cylinder volume (Locobase 9456). As noted in the P3-b entry, this engine's performance was apparently more satisfactory.

After the compound's conversion in 1904, the two formed a small sub-class of their own, although the 329 now rolled on 80" drivers. In the teens, both were redesignated P4-d when they were refitted with new boilers pressed to 225 psi (328) in May 1914 and 220 psi (329) in February 1915. Their fireboxes had 4 fewer sq ft in the firebox and a slightly smaller grate area. Weight by now had increased to 107,825 lb (48,909 kg) on the drivers and 192,700 lb (87,407 kg) for the engine. With the higher BP, tractive effort stood at 24,100 lb (10,932 kg) for the 328 and 24,700 lb (11,204 kg) for 329.

The two were scrapped a month apart in 1933--February for 328, and March for 329.


Class P4-b/P4-c (Locobase 9458)

Data from RDG 11 - 1926 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. See also DeGolyer, Volume 24, p. 274. Works numbers were 20529, 20531, 22266, 22267 in May 1903; 22274, 22287 in June; 24164, 24172 in April 1904; 24188, 24199, 24225, 24272 in May.

Baldwin blended the distinctive demands of an anthracite road burning light-drafted culm, the design philosophy of express Atlantic locomotion, and a waning interest in compounding in this decade of simple-expansion engines.

The class was rebuilt by the Reading in 1914; see Locobase 9457.


Class P4-e/P4-f (Locobase 9457)

Data from RDG 11 - 1926 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

In the mid-teens, the Reading overhauled all ten Baldwin 7-foot Atlantics originally supplied in 1903-1904 (Locobase 9458). P-4e refers to the 1903 batch, P4-f to the 1904s. Ot the 10, 7 received 80" drivers and that septet is represented in the specifications.

All ten were scrapped between July 1933 and June 1935.


Class P5-c (Locobase 4100)

It's hard to believe one could fit a larger grate on a camelback Atlantic that this one. Add to the novelty a three-cylinder layout and you have the third of three experiments by Edward Elliott of the Philadelphia & Reading. Additional data from Report of proceedings of the ... annual convention of the American Railway Master Mechanics' Association, (American Railway Master Mechanics' Association, 1913), pp. 276-280.

Data from Paul T. Warner (RLHS Bulletin #58). Note that the BP is slightly lower than that of 303. Also, Warner notes that the heating surface includes the Schmidt superheater; Locobase estimates the superheater area based on several other US locomotives with similar flue count, length, and diameter.

Warner's best time behind any locomotive came one morning when 344 clipped off 12 miles of descending grade in the Lehigh Valley in 8 min 4 sec or 89 mph.


Class P5-sd/e (Locobase 6453)

Data from Philadelphia & Reading 9 Sept 1914 erecting diagram for this more conventional Atlantic camelback. The two piston valves each measured 13" in diameter and had 7" travel with 5/16" lead and 1 3/8" lap. The diagram notes that the P-5d has 23" x 26" cylinders with 80" drivers while the P-5e had the 23" x 27" and 86" drivers shown in the specs.

The EHS dropped when the locomotives were superheated. Axle loadings ranged from 63,650 lb to the 68,125 lb shown in the specs. At a later date, the boiler saw the removal of 28 tubes and a drop in tube & flue heating surface area to 2,707 sq ft. Total EHS then came to 2,981 sq ft.

The RDG 11 - 1926 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection do not show superheater area. The figure given in the specs is an estimate based on installations of similar flue count and length.


Class P6-a (Locobase 2809)

Another unusual Reading design, this one conceived by chief draftsman Edward O. Elliott. Add to the camelback with its enormous firebox (108" wide) a 3-cylinder layout that originally was compound, later simpled as depicted here. Edwin Alexander (1950) observes that this were the first Reading engines to have Walschaerts valve gear. Additional data from Report of proceedings of the ... annual convention of the American Railway Master Mechanics' Association, (American Railway Master Mechanics' Association, 1913), pp. 276-280.

Paul T. Warner (RLHS Bulletin #58) supplied the heating surface and weights information, noting that the former included a Taylor superheater. This was a chamber some 3 feet long in the front boiler course. Warner concluded that it was probable " that the device ...gave only a very moderate degree of superheat." He notes that a later upgrade included the Schmidt type of superheater.


Class P6-b (Locobase 4099)

Data from RDG 11 - 1926 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Additional data from Report of proceedings of the ... annual convention of the American Railway Master Mechanics' Association, (American Railway Master Mechanics' Association, 1913), pp. 276-280.

The second of three trial 3-cylinder camelback Atlantics (talk about an exclusive club!), this engine had a surprisingly high boiler pressure for the time. It was likely reduced soon after the 300 entered service. Data from Paul T. Warner (RLHS Bulletin #58), who notes that the heating surface area includes a Taylor superheater. (See notes for engine 303, Locobase 2809)

Later superheated with a more conventional boiler; see Locobase 9459.


Class P6-sb (Locobase 9459)

Locobase 4099 describes the second of three trial 3-cylinder camelback Atlantics built by the Reading in the early teens.

As with the other experiments, operational reality soon dictated a conversion to a more conventional, but still camelback, layout. An oddity in this engine's boiler, however, is the provision of 18 1 3/4" tubes in addition to the 154 2" tubes shown in the specs. The superheater flues were slightly narrower than the conventional as well.


Class P7-sb (Locobase 9448)

Data from RDG 11 - 1926 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Few railroads managed to make the 4-4-4 wheel arrangement work and the Reading fit the majority mold. Within a year of introducing its C1-a (Locobase 2810), the company rebuilt the quartet as 4-4-2s.

A principal difference was a 13.5 sq ft (1.25 sq m) drop in grate area, achieved by reducing firebox length by 18" (457 mm) to 126 1/4" (3.21 m),. Total wheelbase decreased by 4 feet (1,219 mm) as a much larger single-axle trailing truck (54"/1,372 mm) supported the firebox . Another drop was the 8 1/2 short ton (7.7 metric tonne) reduction in adhesion weight while weights on the trucks changed very little. The factor of adhesion changed relatively little from the C-1a's 4.1 because boiler pressure was reduced by 25 psi (1.72 bar). Piston valve diameter grew to 14" (356 mm).

Specifications by Steve Llanso of Sweat House Media
Class100376 / D-10a/P-1bP-3bP1-cP1-e
Locobase ID14994 15924 9456 12415 9449
RailroadPhiladelphia & ReadingPhiladelphia & ReadingPhiladelphia & ReadingPhiladelphia & ReadingPhiladelphia & Reading
CountryUSAUSAUSAUSAUSA
Whyte4-4-24-4-24-4-24-4-24-4-2
Number in Class14144
Road Numbers100376-377, 383-384/313-314, 316329318-321311-314
GaugeStdStdStdStdStd
Number Built1414
BuilderReadingBurnham, Williams & CoReadingBurnham, Williams & CoReading
Year1898190219001900
Valve GearWalschaertStephensonStephensonStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase 6.50'14.50' 7.25' 7.25' 7.25'
Engine Wheelbase24.62'26.58'26.58'26.58'26.58'
Ratio of driving wheelbase to overall engine wheebase 0.26 0.55 0.27 0.27 0.27
Overall Wheelbase (engine & tender)53.17'
Axle Loading (Maximum Weight per Axle)48000 lbs55150 lbs
Weight on Drivers98375 lbs76000 lbs107825 lbs88000 lbs93200 lbs
Engine Weight161500 lbs141000 lbs192700 lbs164000 lbs166000 lbs
Tender Light Weight80000 lbs152000 lbs120000 lbs152000 lbs
Total Engine and Tender Weight221000 lbs344700 lbs284000 lbs318000 lbs
Tender Water Capacity4000 gals7000 gals5950 gals7000 gals
Tender Fuel Capacity (oil/coal)12.9 tons tons12.9 tons
Minimum weight of rail (calculated)82 lb/yard63 lb/yard90 lb/yard73 lb/yard78 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter68.50"84.25"84.25"84.50"74"
Boiler Pressure225 psi200 psi200 psi200 psi200 psi
High Pressure Cylinders (dia x stroke)18" x 24"13" x 26"15" x 24"13" x 26"20" x 26"
Low Pressure Cylinders (dia x stroke)22" x 26" (2)25" x 24" (2)22" x 26" (2)
Tractive Effort21710 lbs13143 lbs16024 lbs13104 lbs23892 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.53 5.78 6.73 6.72 3.90
Heating Ability
Firebox Area120 sq. ft190.20 sq. ft182 sq. ft179.70 sq. ft183 sq. ft
Grate Area63 sq. ft76 sq. ft79.30 sq. ft75.90 sq. ft76 sq. ft
Evaporative Heating Surface1274 sq. ft1835 sq. ft2944 sq. ft2673 sq. ft1583 sq. ft
Superheating Surface
Combined Heating Surface1274 sq. ft1835 sq. ft2944 sq. ft2673 sq. ft1583 sq. ft
Evaporative Heating Surface/Cylinder Volume180.23459.41599.75669.21167.44
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1417515200158601518015200
Same as above plus superheater percentage1417515200158601518015200
Same as above but substitute firebox area for grate area2700038040364003594036600
Power L168106840793887946518
Power MT305.23396.83324.61440.62308.36

Specifications by Steve Llanso of Sweat House Media
ClassP1-fP2-aP2-bP3-aP3-c
Locobase ID9450 9451 9452 16161 9453
RailroadPhiladelphia & ReadingPhiladelphia & ReadingPhiladelphia & ReadingPhiladelphia & ReadingPhiladelphia & Reading
CountryUSAUSAUSAUSAUSA
Whyte4-4-24-4-24-4-24-4-24-4-2
Number in Class411866
Road Numbers318-321301, 304-310, 315-317301, 304-310, 315-317322-327322-327
GaugeStdStdStdStdStd
Number Built1186
BuilderReadingReadingReadingBurnham, Williams & CoReading
Year19041907190019001903
Valve GearStephensonStephensonWalschaertStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase 7.25' 7.17' 7.17' 7.25' 7.25'
Engine Wheelbase26.58'27.08'27.08'26.58'26.58'
Ratio of driving wheelbase to overall engine wheebase 0.27 0.26 0.26 0.27 0.27
Overall Wheelbase (engine & tender)
Axle Loading (Maximum Weight per Axle)50720 lbs51775 lbs
Weight on Drivers95750 lbs104900 lbs102050 lbs84000 lbs100450 lbs
Engine Weight175950 lbs192000 lbs192400 lbs164000 lbs176750 lbs
Tender Light Weight152000 lbs152000 lbs120000 lbs
Total Engine and Tender Weight327950 lbs344400 lbs284000 lbs
Tender Water Capacity7000 gals7000 gals5950 gals
Tender Fuel Capacity (oil/coal)12.9 tons tons12.9 tons8 tons tons
Minimum weight of rail (calculated)80 lb/yard87 lb/yard85 lb/yard70 lb/yard84 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter84"78"78"84.25"84.25"
Boiler Pressure200 psi205 psi205 psi200 psi220 psi
High Pressure Cylinders (dia x stroke)20" x 26"20.5" x 26"20.5" x 26"15" x 24"21" x 24"
Low Pressure Cylinders (dia x stroke)25" x 24" (2)
Tractive Effort21048 lbs24410 lbs24410 lbs16024 lbs23492 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.55 4.30 4.18 5.24 4.28
Heating Ability
Firebox Area175 sq. ft245 sq. ft245 sq. ft224.40 sq. ft219 sq. ft
Grate Area76 sq. ft85.50 sq. ft85.50 sq. ft80.70 sq. ft80.70 sq. ft
Evaporative Heating Surface2425 sq. ft2384 sq. ft2384 sq. ft2541 sq. ft2550 sq. ft
Superheating Surface
Combined Heating Surface2425 sq. ft2384 sq. ft2384 sq. ft2541 sq. ft2550 sq. ft
Evaporative Heating Surface/Cylinder Volume256.51240.02240.02517.65265.04
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1520017528175281614017754
Same as above plus superheater percentage1520017528175281614017754
Same as above but substitute firebox area for grate area3500050225502254488048180
Power L1977496839683754411703
Power MT450.09407.00418.37395.99513.70

Specifications by Steve Llanso of Sweat House Media
ClassP3-dP4-a/P4-dP4-b/P4-cP4-e/P4-fP5-c
Locobase ID9454 9455 9458 9457 4100
RailroadPhiladelphia & ReadingPhiladelphia & ReadingPhiladelphia & ReadingPhiladelphia & ReadingPhiladelphia & Reading
CountryUSAUSAUSAUSAUSA
Whyte4-4-24-4-24-4-24-4-24-4-2
Number in Class6210101
Road Numbers322-327328/328-329330-339330-332, 335-338344
GaugeStdStdStdStdStd
Number Built1101
BuilderReadingReadingBurnham, Williams & CoReadingReading
Year19141902190019141912
Valve GearStephensonStephensonStephensonStephensonWalschaert
Locomotive Length and Weight
Driver Wheelbase 7.25' 7.25' 7.25' 7.25' 7.25'
Engine Wheelbase26.58'26.58'26.58'26.58'28'
Ratio of driving wheelbase to overall engine wheebase 0.27 0.27 0.27 0.27 0.26
Overall Wheelbase (engine & tender)
Axle Loading (Maximum Weight per Axle)53375 lbs63650 lbs
Weight on Drivers100450 lbs81000 lbs101625 lbs105350 lbs128300 lbs
Engine Weight176750 lbs171000 lbs196500 lbs196175 lbs233200 lbs
Tender Light Weight129000 lbs152000 lbs152000 lbs162000 lbs
Total Engine and Tender Weight300000 lbs348500 lbs348175 lbs395200 lbs
Tender Water Capacity5950 gals7000 gals7000 gals8000 gals
Tender Fuel Capacity (oil/coal)12.9 tons12.9 tons12.9 tons
Minimum weight of rail (calculated)84 lb/yard68 lb/yard85 lb/yard88 lb/yard107 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter84.25"84.25"84.25"80"80"
Boiler Pressure220 psi200 psi225 psi225 psi230 psi
Cylinders (dia x stroke)21" x 24"21" x 24"21" x 24"21" x 24"19" x 24"
Tractive Effort23492 lbs21356 lbs24026 lbs25302 lbs31759 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.28 3.79 4.23 4.16 4.04
Heating Ability
Firebox Area219 sq. ft186 sq. ft180 sq. ft180 sq. ft266 sq. ft
Grate Area80.70 sq. ft80 sq. ft79.30 sq. ft79.30 sq. ft94.50 sq. ft
Evaporative Heating Surface1851 sq. ft2948 sq. ft3043 sq. ft3043 sq. ft2627 sq. ft
Superheating Surface470 sq. ft
Combined Heating Surface1851 sq. ft2948 sq. ft3043 sq. ft3043 sq. ft3097 sq. ft
Evaporative Heating Surface/Cylinder Volume192.39306.41316.28316.28222.37
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1775416000178431784321735
Same as above plus superheater percentage1775416000178431784324995
Same as above but substitute firebox area for grate area4818037200405004050070357
Power L1945911320129481229521252
Power MT415.20616.20561.78514.59730.36

Specifications by Steve Llanso of Sweat House Media
ClassP5-sd/eP6-aP6-bP6-sbP7-sb
Locobase ID6453 2809 4099 9459 9448
RailroadPhiladelphia & ReadingPhiladelphia & ReadingPhiladelphia & ReadingPhiladelphia & ReadingPhiladelphia & Reading
CountryUSAUSAUSAUSAUSA
Whyte4-4-24-4-24-4-24-4-24-4-2
Number in Class92114
Road Numbers340-343, 345-349303300303350-353
GaugeStdStdStdStdStd
Number Built9211
BuilderReadingReadingReadingReadingReading
Year19121909191119111916
Valve GearWalschaertWalschaertWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase 7.75' 7.25' 7.25' 7.25' 7.25'
Engine Wheelbase29.25'28'28'28'29.25'
Ratio of driving wheelbase to overall engine wheebase 0.26 0.26 0.26 0.26 0.25
Overall Wheelbase (engine & tender)
Axle Loading (Maximum Weight per Axle)68125 lbs68863 lbs
Weight on Drivers134500 lbs106150 lbs108000 lbs122000 lbs129210 lbs
Engine Weight220500 lbs205400 lbs208000 lbs217450 lbs231925 lbs
Tender Light Weight162000 lbs162000 lbs183700 lbs
Total Engine and Tender Weight382500 lbs379450 lbs415625 lbs
Tender Water Capacity8000 gals7000 gals7000 gals8000 gals9000 gals
Tender Fuel Capacity (oil/coal)12.9 tons10.5 tons10.5 tons12.9 tons15 tons
Minimum weight of rail (calculated)112 lb/yard88 lb/yard90 lb/yard102 lb/yard108 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter86"80"80"80"80"
Boiler Pressure200 psi225 psi240 psi215 psi215 psi
Cylinders (dia x stroke)23" x 27"18.5" x 24"19" x 24"22" x 26"23.5" x 26"
Tractive Effort28234 lbs29455 lbs33140 lbs28747 lbs32800 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.76 3.60 3.26 4.24 3.94
Heating Ability
Firebox Area274 sq. ft260 sq. ft260 sq. ft260 sq. ft292 sq. ft
Grate Area94.50 sq. ft90 sq. ft90 sq. ft90 sq. ft94.50 sq. ft
Evaporative Heating Surface2854 sq. ft2846 sq. ft3345 sq. ft2957 sq. ft2979 sq. ft
Superheating Surface461 sq. ft530 sq. ft
Combined Heating Surface3315 sq. ft2846 sq. ft3345 sq. ft2957 sq. ft3509 sq. ft
Evaporative Heating Surface/Cylinder Volume219.82254.10283.15258.50228.24
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1890020250216001935020318
Same as above plus superheater percentage2154620250216001935023365
Same as above but substitute firebox area for grate area6247258500624005590072197
Power L11848711105125821066820226
Power MT606.05461.28513.68385.56690.20

Reference


If you have any railroad data such as diagram books, rail station plans or anything else that you would be willing to share, please contact us.