St Louis-San Francisco 4-6-2 "Pacific" Locomotives of the USA


Class Details by Steve Llanso of Sweat House Media

Class 1000 (Locobase 8628)

Data from StLSF 1904, StLSF 1908 description, and SL&SF All Time Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works numbers ran from 28690-28699 in February 1904.

These were the first Pacifics on the Frisco and almost the first 4-6-2s in North America. They had small boilers and grates and rode on medium-height drivers; on the other hand, they were fitted with piston valves. Baldwin supplied another 5 in the same year.

Some time later they were superheated; see Locobase 8629.


Class 1000 - superheated (Locobase 8629)

Data from StLSF 1904, StLSF 1908 description, and SL&SF All Time Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Locobase 8628 describes the first Frisco Pacifics from Brooks. Small though they were, the class was still deemed suitable for superheating. In the process, the 2 1/4" tubes were replaced by 2" tubes and a 22-flue superheating assembly installed. Unusually for such conversions, the boiler pressure remained set at 200 psi. Piston valves measured 11" in diameter.

All of the class carried on until the late 1940s. 1000 was "dismissed from service" first in September 1946. The others followed with 1005 closing out the class in December 1948.


Class 1010 (Locobase 8630)

Data from StLSF 1904, StLSF 1908 description, and SL&SF All Time Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works numbers were 23744, 23751-52, 23844, 23903 in March 1904.

In the same year as the Brooks Pacifics came these Baldwin Pacifics. The Brooks engines used piston valves, the Baldwins continued with slide valves. Otherwise, the two designs were quite similar. Locobase noted that the 1904 diagrams showed clearly a firebox heating surface area of 102.5 sq ft. As small as that figure is, he has retained it because he can find no documentation for another number. Later this class was credited with 171.1 sq ft, but that included 2 Nicholson thermic syphons.

Some time later this class superheated; see Locobase 8631.


Class 1011 - superheated (Locobase 8631)

Data from StLSF 1904, StLSF 1908 description, and SL&SF All Time Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works numbers were 23744, 23751-52, 23844, 23903 in March 1904.

The Frisco's makeover of the Brooks locomotives (Locobase 8630) took significant liberties with the original design. What they did to the Baldwins ran even deeper. The same reduction in tube diameter occurred - from 2 1/4" to 2"and the cylinders were bored out to 21". But the superheater ratio ran even higher as more small tubes were sacrificed for superheater flues and elements. At the same time, the slide valves of the original design were replaced by relatively capacious 12" piston valves. Moreover, the firebox was extensively reworked, gaining 2 Nicholson thermic syphons in the process.

Of the class, the last 4 were retired beginning in March 1949 and ending in September 1951.


Class 1015 - delivered (Locobase 13528)

Data from Baldwin Locomotive Works Specification for Engines, 1888, as digitized by the DeGolyer Library of Southern Methodist University, Volume 33, pp. 218-219. Works numbers were 34154-34159, 34193-34195, 34209-34212, 34227, 34234 in January 1910; 34251-34253, 34265, 34328 in February 1910 35275-35278 in September; and 35352 in October. (Thanks to Antonio Fontanelli, whose 3 March 2013 email pointed out a discrepancy in the builder's numbers.)

These were among the first North American locomotives to be delivered with superheaters. Notice the low boiler pressure of 160 psi, a setting probably derived from an expectation that superheating steam would allow a reduction of boiler pressure. (Later thinking said, "Take both the superheat and the higher pressure for even more power and accept the higher maintenance cost.").

The boiler would be substantially made over; the result is seen in Locobase 8632.


Class 1015 - rebuilt (Locobase 8632)

Data from StLSF 1908 description, StLSF 1930, StL&SF 11 - 1943, and SL&SF All Time Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Locobase 13528 details this class as it was delivered in 1910. When the Frisco overhauled the set some time in the late 1920s and early 1930s, they went with a new boiler that had smaller-diameter tubes. Fourteen -- 1015, 1019, 1021, 1023, 1025, 1036, 1027, 1033, 1031, 1034-1035, 1016, 1018, 1017 -- were fitted with 24"-diameter cylinders and boilers pressed to 200 psi. Thus, although the cylinder volume dropped, the increase in BP increased tractive effort. Five retained Walschaert valve gear; the rest were refitted with Baker gear.

Three--1018, 1025, and 1031--would be streamlined in 1939; see Locobase 8633. Three more locomotives--1025, 1034, and 1036 -- would share the power dimensions.

The class stayed in service for about 40 years each and were "dismissed from service" between 31 May 1949 and 11 December 1951.


Class 1018 streamlined (Locobase 8633)

Data from StLSF 11 - 1943 and SL&SF All Time Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Locobase 8632 describes the original class of Pacifics from which this small group of rebuilds was drawn. The three were taken in hand to properly grace the Firefly, a new streamlined train service between Kansas City and Oklahoma City via Tulsa. Note the variety of tweaks applied to a design that already had garnered smaller cylinders and a higher boiler pressure: taller drivers, oil-burning firebox, a bigger tender, and substantially more weight on the drivers and overall. 1018 & 1031 had Walschaert gear, 1026 had Baker gear.

The streamline casing that now shrouded the boiler had a bullet nose, faired stack, and thick valence over the open running gear. A broad band of color along the valence and the tender was simply lettered "Frisco Lines." As Drury (1993) points out, "Streamlined or no, the bell and the whistle were out front where they could be heard."

As far as pictures can show, the trio retained their shrouds throughout the rest of their careers. 1026 was first to be "dismissed from service" on 31 May 1949. 1031 followed on 4 October while 1018 ran until 22 May 1950.


Class 1040 (Locobase 7586)

Data from reproduction of 1913 Alco Bulletin 1016 on Richard Leonard's http://www.railarchive.net/alcopacifics/index.html (accessed 16 June 2006). Data also from StLSF 1930, StL&SF 11 - 1943, and SL&SF All Time Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

According to Drury (1993), this class of Pacifics (works# 50553-50572) shared many components with the 1306-class Consolidations. Later, the Frisco rebuilt this class into oil-burners with 24" x 28" cylinders and 73" drivers; see Locobase 8634.

They were "dismissed from service" in the 13 months between 30 November 1950 and 27 December 1951.


Class 1040 - rebuilt 69"" (Locobase 8634)

Data from StLSF 1930, StL&SF 11 - 1943, and SL&SF All Time Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Most of the class profiled in Locobase 7584 was reworked in the late 1920s and early 1930s. Almost all were converted to oil-burning beginning in 1924, cylinder diameter dropped by 2 inches, boiler pressure rose by 30 psi, and the brick arch was removed from the firebox. This last alteration was offset by installation of a Nicholson thermic syphon, which increased firebox heating surface. One of this class rode on 73" drivers.

Five others had a further makeover; see Locobase 8635.

They were "dismissed from service" in the 13 months between 30 November 1950 and 27 December 1951.


Class 1042 - rebuilt 73"" (Locobase 8635)

Data from StLSF 1930, StL&SF 11 - 1943, and SL&SF All Time Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Locobase 8634 shows the results of the Frisco's rebuilding program in the late 1920s and early 1930s. For seven of the locomotives, that was not the end of the makeover. Tubes were removed in favor of more superheater area, which now achieved superpower proportions.


Class 1060 (Locobase 8535)

Data from reproduction of the Frisco Man newsletter, Vol XI, # 7 (July 1917), pp. 13-16, found on the Frisco Lines history website -- http://198.209.8.207/lochist/frisco/magazines/fm_1917_07/fm_1917_07.pdf, accessed 4 July 2007. (Thanks to Chris Hohl for his 24 October 2015 email describing the change from Baker to Walschaert gear.) See also DeGolyer, Vol 55, pp. 273+. Works numbers were 45358, 45387 in March 1917; 45464-45466, 45511-45512 in April; 45580, 45631 in May; and 45701 in June.

According to the Frisco Man article, these new Pacifics were fitted with the Jacobs-Shupert welded firebox. The author then gives a detailed description of the construction of this unusual variation. Among other features were the 13"-diameter (331 mm) piston valves, Street mechanical stoker, and Ragonnet power reverse mechanism.

Certainly in comparison with the earlier class of Frisco Pacifics, these were much bigger and more powerful locomotives. But the fireboxes leaked, which sapped the design's potential. There may also have been issues with the Baker valve gear; Chris Hohl points out that the 1060s were refitted with Walschaert's gear before they were extensively rebuilt.

Two decades after their delivery (they didn't want to rush things?), Frisco reconstructed the class as bigger and better 4-6-4s; see Locobase 165.

Specifications by Steve Llanso of Sweat House Media
Class10001000 - superheated10101011 - superheated1015 - delivered
Locobase ID8628 8629 8630 8631 13528
RailroadSt Louis-San Francisco (Frisco/(SLSF)St Louis-San Francisco (Frisco/(SLSF)St Louis-San Francisco (Frisco/(SLSF)St Louis-San Francisco (Frisco/(SLSF)St Louis-San Francisco (Frisco/(SLSF)
CountryUSAUSAUSAUSAUSA
Whyte4-6-24-6-24-6-24-6-24-6-2
Number in Class10105525
Road Numbers1000-10091000-10091010-10141010-10141015-1039
GaugeStdStdStdStdStd
Number Built10525
BuilderAlco-BrooksFriscoBurnham, Williams & CoFriscoBaldwin
Year19041904190419301910
Valve GearWalschaertWalschaertWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase12.33'12.33'12.33'12'12.50'
Engine Wheelbase31.50'31.67'30'30'32.75'
Ratio of driving wheelbase to overall engine wheebase 0.39 0.39 0.41 0.40 0.38
Overall Wheelbase (engine & tender)60'57'60.72'62.12'64.75'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers123400 lbs139400 lbs118800 lbs131700 lbs145000 lbs
Engine Weight193550 lbs204900 lbs191000 lbs210100 lbs212000 lbs
Tender Light Weight134200 lbs134200 lbs134200 lbs165200 lbs151800 lbs
Total Engine and Tender Weight327750 lbs339100 lbs325200 lbs375300 lbs363800 lbs
Tender Water Capacity6000 gals6000 gals6000 gals7500 gals8100 gals
Tender Fuel Capacity (oil/coal)13 tons13 tons13 tons13 tons11.5 tons
Minimum weight of rail (calculated)69 lb/yard77 lb/yard66 lb/yard73 lb/yard81 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter69"69"69"69"69"
Boiler Pressure200 psi200 psi200 psi200 psi160 psi
Cylinders (dia x stroke)20" x 26"21" x 26"20" x 26"21" x 26"26" x 28"
Tractive Effort25623 lbs28250 lbs25623 lbs28250 lbs37307 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.82 4.93 4.64 4.66 3.89
Heating Ability
Firebox Area164 sq. ft146.70 sq. ft102.50 sq. ft171.10 sq. ft185 sq. ft
Grate Area42.10 sq. ft42.10 sq. ft43 sq. ft43.30 sq. ft51 sq. ft
Evaporative Heating Surface2958 sq. ft2342 sq. ft2928 sq. ft2112 sq. ft2851 sq. ft
Superheating Surface531 sq. ft602 sq. ft626 sq. ft
Combined Heating Surface2958 sq. ft2873 sq. ft2928 sq. ft2714 sq. ft3477 sq. ft
Evaporative Heating Surface/Cylinder Volume312.89224.70309.71202.63165.70
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation84208420860086608160
Same as above plus superheater percentage842099368600105659629
Same as above but substitute firebox area for grate area3280034621205004174834928
Power L191911733283701850410063
Power MT492.61822.32465.98929.25459.00

Specifications by Steve Llanso of Sweat House Media
Class1015 - rebuilt1018 streamlined10401040 - rebuilt 69""1042 - rebuilt 73""
Locobase ID8632 8633 7586 8634 8635
RailroadSt Louis-San Francisco (Frisco/(SLSF)St Louis-San Francisco (Frisco/(SLSF)St Louis-San Francisco (Frisco/(SLSF)St Louis-San Francisco (Frisco/(SLSF)St Louis-San Francisco (Frisco/(SLSF)
CountryUSAUSAUSAUSAUSA
Whyte4-6-24-6-24-6-24-6-24-6-2
Number in Class25320157
Road Numbers1015-10391018, 1026, 10311040-10591040-10591042, 44-45, 51, 59
GaugeStdStdStdStdStd
Number Built20
BuilderFriscoFriscoAlco-SchenectadyFriscoFrisco
Year1939191219291930
Valve GearBakerBaker or WalschaertWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase12.50'12.50'12.50'12.50'12.50'
Engine Wheelbase32.75'32.75'33.08'33.12'33.12'
Ratio of driving wheelbase to overall engine wheebase 0.38 0.38 0.38 0.38 0.38
Overall Wheelbase (engine & tender)64.72'69.87'56.94'65.98'65.98'
Axle Loading (Maximum Weight per Axle)63150 lbs
Weight on Drivers145500 lbs153700 lbs158000 lbs159200 lbs178850 lbs
Engine Weight225500 lbs239200 lbs260500 lbs262600 lbs296750 lbs
Tender Light Weight151800 lbs208000 lbs161200 lbs175600 lbs211100 lbs
Total Engine and Tender Weight377300 lbs447200 lbs421700 lbs438200 lbs507850 lbs
Tender Water Capacity8100 gals10000 gals8100 gals8100 gals10000 gals
Tender Fuel Capacity (oil/coal)11.5 tons3800 gals14 tons4000 gals4000 gals
Minimum weight of rail (calculated)81 lb/yard85 lb/yard88 lb/yard88 lb/yard99 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter69"73"69"69"73"
Boiler Pressure200 psi200 psi175 psi205 psi205 psi
Cylinders (dia x stroke)24" x 28"24" x 28"26" x 28"24" x 28"24" x 28"
Tractive Effort39736 lbs37558 lbs40805 lbs40729 lbs38497 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.66 4.09 3.87 3.91 4.65
Heating Ability
Firebox Area214 sq. ft215.70 sq. ft204 sq. ft236.40 sq. ft236.40 sq. ft
Grate Area50.90 sq. ft50.90 sq. ft50.90 sq. ft50.90 sq. ft50.90 sq. ft
Evaporative Heating Surface2831 sq. ft2780 sq. ft3676 sq. ft3692 sq. ft3743 sq. ft
Superheating Surface679 sq. ft679 sq. ft759 sq. ft833 sq. ft1041 sq. ft
Combined Heating Surface3510 sq. ft3459 sq. ft4435 sq. ft4525 sq. ft4784 sq. ft
Evaporative Heating Surface/Cylinder Volume193.10189.62213.65251.83255.31
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation101801018089081043510435
Same as above plus superheater percentage1211412216104221231312730
Same as above but substitute firebox area for grate area5093251768417695718559124
Power L11570716547134831989324318
Power MT713.98712.03564.40826.44899.28

Specifications by Steve Llanso of Sweat House Media
Class1060
Locobase ID8535
RailroadSt Louis-San Francisco (Frisco/(SLSF)
CountryUSA
Whyte4-6-2
Number in Class10
Road Numbers1060-1069
GaugeStd
Number Built10
BuilderBaldwin
Year1917
Valve GearBaker
Locomotive Length and Weight
Driver Wheelbase13'
Engine Wheelbase33.92'
Ratio of driving wheelbase to overall engine wheebase 0.38
Overall Wheelbase (engine & tender)71.58'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers190000 lbs
Engine Weight296000 lbs
Tender Light Weight190000 lbs
Total Engine and Tender Weight486000 lbs
Tender Water Capacity10000 gals
Tender Fuel Capacity (oil/coal)18 tons
Minimum weight of rail (calculated)106 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter73"
Boiler Pressure200 psi
Cylinders (dia x stroke)26.5" x 28"
Tractive Effort45791 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.15
Heating Ability
Firebox Area284 sq. ft
Grate Area63.50 sq. ft
Evaporative Heating Surface4200 sq. ft
Superheating Surface996 sq. ft
Combined Heating Surface5196 sq. ft
Evaporative Heating Surface/Cylinder Volume234.98
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation12700
Same as above plus superheater percentage15113
Same as above but substitute firebox area for grate area67592
Power L119854
Power MT691.11

Reference


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