El Paso & Southwestern / Southern Pacific / Texas & New Orleans 4-6-2 "Pacific" Locomotives of the USA


Class Details by Steve Llanso of Sweat House Media

Class P-1/P-3 (Locobase 4407)

Data from SP 7 - 1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. See also data from"Report of Committe on Power-Chicago, Rock Island & Pacific Railway-Descriptions of Standard Types of Locomotives," American Engineer and Railroad Journal, Volume 79 ( March 1905), pp. 84-86. P-1 was produced in small batches had Baldwin works #27366-27369 in January 1906; 27465-66 in February; 28660, 28673-74 in July; 28714, 28737-38, 28797, 28826, 28867 in August; 30762-63, 30785-86, 30827, 30906, 30923-24 in May 1907. The identical P-3s all were manufactured in February 1911 as a single batch (36058-36067 in February 1911 ).

These Harriman Common Standard Pacifics were relatively light engines. Although they entered service with slide valves and inside valve gear, they were eventually superheated (see Locobase 8729). Eight were fitted with Walschaerts gear outside, feedwater heaters, and trailing-truck boosters in 1927-1929 and known as P-4s. See 5340 for an introduction to the basic HCS idea.


Class P-1/P-3 - superheated (Locobase 8729)

Data from SP 7 - 1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection

First operated as saturated-boiler Harriman Common Standard Pacifics (see Locobase 4407), this class was superheated in a conversion that had some unusual features. The most striking was the replacement of 2 1/4" tubes with 2" tubes. The tube count didn't decline by quite so much. Moreover, when the superheater area was factored in, the engines now had more combined heating surface area than before.

Those locomotives that retained the inside Stephenson gear also retained their P-1 & P-3 designations. But eight were fitted with Walschaerts gear outside, feedwater heaters, and trailing-truck boosters in 1927-1929 and known as P-4s. They were otherwise identical to the P-1/P-3 superheated variant.


Class P-10 (Locobase 5878)

Data from http://www.ctrc.org/projects/2479-restoration/2479-facts.html, last accessed 16 January 2010. See also DeGolyer, Volume 69, pp. 334+. (Thanks to Chris Hohl for his 30 May 2016 email noting the driver diameter as delivered as well as the loaded tender weight for the 1924 batch.) Works numbers were 57227-38, 57254-55, 57264, 57366 in October 1923 and 57630-57634, 57652-57654 in February 1924.

This class was very similar to the two-years-earlier P-8s, but had Worthington 3-B feed water heaters with capacity of 5,400 US gallons (20,439 litres) per hour. In addition, the last eight had trailing-truck booster engines. See notes on the P-8 design at Locobase 3290. The whistle was a melodious five-chamber chime. The booster was powered by superheated steam and the power reverser was an Alco Type E. The last eight locomotives were delivered with tenders weighing 236,000 lb (107,048 kg).

Page 337 features a list of "For Hereafter" notes that begin with defects in the engines already delivered and a list of changes to allow them to conform to SP shop practices. Perhaps the most important complaint concerned the mounting of the oil burner in the firebox: "Oil burner is fastened to the pan and the brace supporting the rear end of the burner and piping is fastened to the frame, so that when the boiler expands, the burner is pulled out of its natural postion. All bracing for the burnershould be attached to the fire pan, which will make a more practical working proposition."

Locobase notes the oil burner specified in supplemental paragraph 97 was a Van Boden Ingles design supplied by E Sullivan of San Francisco "in accordance with Railroad company's blueprints." The Von Boden Ingles design had received a US patent number (760826) on 24 May 1904. It had been Baldwin's usual option for oil burning for decades. Locobase can't say whether other operators reported similar problems with the bracing.

The Espee steam locomotive roster and photo site

http://espee.railfan.net/steam/sp_steam_p-10.html notes that many of these Pacifics wound up at the head of San Jose-San Francisco commuter service.

Another note from the same site: "3 P-10's were streamlined with skyline casing and side skirts in 1941, coming out looking very much like a 'baby' Gs-4. #2484-2486 were used to haul the San Joaquin Daylight between Oakland and Bakersfield" Connelly's Baldwin list shows five road numbers that were altered (2481-2482, 2488-2489, 2491).


Class P-11 (Locobase 8731)

Data from SP 7 - 1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works numbers were 32437, 32446-32448, 32470-32473, 32502 in December 1907; 32526 in January 1908.

Pretty interesting set of small Pacifics offering relatively small compact cylinders and low drivers, but a larger boiler for the cylinder volume and a small firebox. Such dimensions didn't last very long; see Locobase 8732.


Class P-11 - superheated (Locobase 8732)

Data from SP 7 - 1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works #32437, 32446-32448, 32470-32473, 32502 produced in December 1907 with 32526 following in January 1908.

Apparently the EP & SW recognized that their new Pacifics were under-powered and over-boilered. So, soon after they took delivery, the shops took out 157 tubes and replaced them with 27 large flues for the superheater. They also replaced the cylinders with larger jugs fed by 14" piston valves and rolled the locomotive on 5" taller drivers. Even the firebox was tweaked slightly with the addition of 15 sq ft of arch tubes. Although the boiler was designed for 200 psi, the railroad set the safety valve at a very precise 176 psi.

In this configuration, the class hauled its passenger trains for decades, the first of the class departing in 1939, the last surviving until 1950.


Class P-12 (Locobase 8670)

Data from SP 7 - 1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Similar to the P-6s of the Southern Pacific and the Texas & New Orleans, these EP & SW engines had more cylinder volume and considerably more superheater area. In fact, they had 4the most area of any SP Lines 4-6-2.


Class P-13 (Locobase 168)

Data from T&NO 3 -1932 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. See also DeGolyer, Vol 82, pp. 539+. Works numbers were 60513-60514 in June 1928 and 60564 in July.

After the T & NO bought 9 P-9s in 1923 (Locobase 8669), it returned to Baldwin five years later for another three in June-July 1928. The latter group was dubbed P-13, possibly because of the 6,500-lb weight gain.

The firebox had combustion chamber that contributed 68 sq ft (6.3 sq m) to direct heating surface and the boiler was fitted with a Worthington feed water heater. Travel in the 14" (356 mm) diameter piston valves at 75% cut-off was 6 1/2". Said to be near-duplicates of the P-10.

Retired in 1954-1955 from Espee's Texas lines.


Class P-14 (Locobase 8733)

Data from SP Menke All-Time Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Locobase 8668 showed the P-6 as it was delivered. As streamlining became the rage on railroads around the world in the 1930s, the Espee couldn't help but join the fun. They enshrouded three of their P-6s in bullet-nosed casings and set them to work pulling the Sunbeam and the Hustler. The Sunbeam's color scheme emulated the Daylight's brilliant oranges and the effect was of a compressed GS-4 and accompanying train as it hurried the 264 miles between Houston & Dallas in less than 4 1/2 hours.

This premium service endured until 1955.


Class P-4 (Locobase 8730)

Data from SP 7 - 1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection

As noted in Locobase 8729, many of the Harriman Common Pacifics were later superheated. Eight were further modified with Walschaerts gear outside, feedwater heaters, and trailing-truck boosters in 1927-1929 and known as P-4s. They also carried cylinders measuring one inch more in diameter and put 7 tons more weight on their drivers.

All of the P-4s lasted into the 1950s.


Class P-5 (Locobase 3289)

See Railway Age 2 July 1921 for data. Works numbers ran 38137-38144 (road 2445-2452), 38168-38169 (road 2438-2439), and 38192-38196 (road 2440-2444), all in August 1912.

Essentially P-3s (Locobase 4407), but with Walschaert gear. These were the last class of Harriman Common Standard Pacifics. The Texas & New Orleans also received P-5s with larger tenders in the same year; see Locobase 8666.

Retirements began in 1947 and extended to 1953.


Class P-5 (Locobase 8666)

Data from T&NO 3 -1932 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Produced in two batches in June 1912 (works #37959-37964 and 37981-37984), this class preceded the slightly larger P-5s (Locobase 3289) that went to the Southern Pacific in August. The 900-902 was assigned to the Morgan's Louisiana & Texas subsidiary, 903-905 went to the Louisiana Western, and 906-909 to the Texas & New Orleans.

All enjoyed a long working life with the first two going for scrap in June 1952 and the last two in November 1955.


Class P-6 (Locobase 8667)

Data from T&NO 3 -1932 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Apparently it was acceptable practice on the Espee to buy Pacifics from a builder other than Baldwin. This class of 12 was part of a single batch delivered both to the T & NO and to its partner (and later owner), which took 6, slightly lighter engines (see Locobase 8668).

The jump in size from the P-5s delivered just a year earlier is striking. The grate is considerably larger and boiler has more tubes and flues and each has a greater diameter than its 1912 counterpart. Such evaporative generosity was occasioned by an equal increase in cylinder volume. The result was a significant step up from the Harriman Common Standard design.


Class P-6/P-7 (Locobase 8668)

Data from T&NO 3 -1932 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Locobase 8667 discusses all of the changes wrought in the Pacific design once the Southern Pacific chose to transcend the Harriman Common Pacific. This 6-engine class was quite similar, possessing two more tubes, but otherwise identical. These engines also had a slightly lower axle loading. Two ex-Arizona Eastern Pacifics built to the same specifications were classed as P-7.


Class P-8 (Locobase 3290)

Data from Railway Age 2 July 1921. See also DeGolyer, Vol 69, pp. 281+. Works numbers were 54396-54397, 54468-54480 in January 1921.

RA reported that these engines were to serve the Ogden, Utah-Carlin, Nev. section. This 247-mile stretch of road included a maximum grade of 1.5% over which one P-8 would take an eleven-car, 875-ton trailing load.

Said by Farrington (Railroading Coast to Coast, 1976) to be a duplicate of 613 on the Espee's Texas Lines. Piston valves measured 14" (356 mm) in diameter. Power reverser was the Ragonnet Type B. (The fourteen P-10s delivered in 1923 had feedwater heaters and the last eight had trailing-truck booster engines, but were otherwise similar to the P-8s; see Locobase 5878.)

RA notes the long stroke of these passenger engines and acknowledges that it's longer than was usual practice at the time. Its adoption, says RA, "was based on the results of numerous tests ... which justified the use of a longer stroke with superheated steam." RA added that the locomotives' performance had proved "that no mistake was made."

This class endured to the end of steam on the Espee, being retired in 1953-1958.


Class P-9 (Locobase 8669)

Data from T&NO 3 -1932 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. See also DeGolyer, Volume 69, p. 297. Works numbers were 56313-56321 in March 1923 and 56484-56488 in May.

Baldwin produced these near-sisters of the Espee P-8s (Locobase 3290) in two 1923 batches; they preceded the Espee's own P-10s (5878) by about six months. Their cylinders also used 14" (356 mm) piston valves to supply steam and Worthington 3-B feed water heaters with 5,400 gallons/hour (20,439 litres) capacity. Compared to the SP's engines, these ran a slightly higher boiler pressure and weighed more.

Specifications by Steve Llanso of Sweat House Media
ClassP-1/P-3P-1/P-3 - superheatedP-10P-11P-11 - superheated
Locobase ID4407 8729 5878 8731 8732
RailroadSouthern Pacific (SP)Southern Pacific (SP)Southern Pacific (SP)El Paso & Southwestern (SP)El Paso & Southwestern (SP)
CountryUSAUSAUSAUSAUSA
Whyte4-6-24-6-24-6-24-6-24-6-2
Number in Class4040141010
Road Numbers2400-2437, 2459-24602400-24372478-2491140-149 / 3100-3109140-149 / 3100-3109
GaugeStdStdStdStdStd
Number Built401410
BuilderBurnham, Williams & CoSPBaldwinBurnham, Williams & CoEP & SW
Year1906192319071913
Valve GearStephensonStephensonWalschaertStephensonWalschaert
Locomotive Length and Weight
Driver Wheelbase13.33'13.33'13'11.83'11.83'
Engine Wheelbase33.33'33.33'35.50'30.75'31'
Ratio of driving wheelbase to overall engine wheebase 0.40 0.40 0.37 0.38 0.38
Overall Wheelbase (engine & tender)63.02'63.02'75.80'63.98'64.21'
Axle Loading (Maximum Weight per Axle)46000 lbs48000 lbs60700 lbs
Weight on Drivers141000 lbs141000 lbs180700 lbs150700 lbs157500 lbs
Engine Weight222000 lbs222000 lbs300000 lbs224000 lbs239500 lbs
Tender Light Weight162200 lbs162200 lbs221900 lbs146133 lbs154800 lbs
Total Engine and Tender Weight384200 lbs384200 lbs521900 lbs370133 lbs394300 lbs
Tender Water Capacity12000 gals7000 gals7000 gals
Tender Fuel Capacity (oil/coal)4000 gals14.5 tons14.5 tons
Minimum weight of rail (calculated)78 lb/yard78 lb/yard100 lb/yard84 lb/yard88 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter77"77"73.50"63"68"
Boiler Pressure200 psi210 psi200 psi200 psi176 psi
Cylinders (dia x stroke)22" x 28"22" x 28"25" x 30"22" x 26"24" x 26"
Tractive Effort29920 lbs31416 lbs43367 lbs33957 lbs32947 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.71 4.49 4.17 4.44 4.78
Heating Ability
Firebox Area174 sq. ft178 sq. ft283 sq. ft185.40 sq. ft200.40 sq. ft
Grate Area49.50 sq. ft49.50 sq. ft70.40 sq. ft52.20 sq. ft52.20 sq. ft
Evaporative Heating Surface3048 sq. ft2749 sq. ft3352 sq. ft3821 sq. ft2922 sq. ft
Superheating Surface548 sq. ft815 sq. ft603 sq. ft
Combined Heating Surface3048 sq. ft3297 sq. ft4167 sq. ft3821 sq. ft3525 sq. ft
Evaporative Heating Surface/Cylinder Volume247.42223.15196.66334.03214.64
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation99001039514080104409187
Same as above plus superheater percentage990012162168961044010749
Same as above but substitute firebox area for grate area3480043735679203708041266
Power L181631875017396871613701
Power MT382.90879.50636.72382.52575.34

Specifications by Steve Llanso of Sweat House Media
ClassP-12P-13P-14P-4P-5
Locobase ID8670 168 8733 8730 3289
RailroadEl Paso & Southwestern (SP)Texas & New Orleans (SP)Southern Pacific (SP)Southern Pacific (SP)Southern Pacific (SP)
CountryUSAUSAUSAUSAUSA
Whyte4-6-24-6-24-6-24-6-24-6-2
Number in Class1033815
Road Numbers3120-3129631-6332455-24572409-10 14,19, 22, 24, 362438-2452
GaugeStdStdStdStdStd
Number Built10315
BuilderAlco-BrooksBaldwinSPSPBaldwin
Year19171928193719271912
Valve GearWalschaertWalschaertWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase13'13'13.33'13.33'13.33'
Engine Wheelbase34.75'35.58'35.67'33.33'33.33'
Ratio of driving wheelbase to overall engine wheebase 0.37 0.37 0.37 0.40 0.40
Overall Wheelbase (engine & tender)78.68'63.02'
Axle Loading (Maximum Weight per Axle)63100 lbs65300 lbs52700 lbs48300 lbs
Weight on Drivers189300 lbs188700 lbs185400 lbs155000 lbs141400 lbs
Engine Weight309100 lbs313800 lbs307500 lbs265000 lbs220900 lbs
Tender Light Weight291100 lbs138100 lbs
Total Engine and Tender Weight604900 lbs359000 lbs
Tender Water Capacity16152 gals7000 gals
Tender Fuel Capacity (oil/coal)4912 gals gals gals2940 gals
Minimum weight of rail (calculated)105 lb/yard105 lb/yard103 lb/yard86 lb/yard79 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter73"73.50"77.50"77"77.50"
Boiler Pressure205 psi200 psi210 psi210 psi200 psi
Cylinders (dia x stroke)26" x 28"25" x 30"25" x 28"23" x 28"22" x 28"
Tractive Effort45181 lbs43367 lbs40306 lbs34337 lbs29727 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.19 4.35 4.60 4.51 4.76
Heating Ability
Firebox Area225 sq. ft283 sq. ft235 sq. ft178 sq. ft178 sq. ft
Grate Area70.30 sq. ft70.50 sq. ft70.30 sq. ft49.50 sq. ft49.50 sq. ft
Evaporative Heating Surface4153 sq. ft3352 sq. ft3953 sq. ft2749 sq. ft2749 sq. ft
Superheating Surface1007 sq. ft836 sq. ft770 sq. ft548 sq. ft556 sq. ft
Combined Heating Surface5160 sq. ft4188 sq. ft4723 sq. ft3297 sq. ft3305 sq. ft
Evaporative Heating Surface/Cylinder Volume241.37196.66248.49204.17223.15
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation144121410014763103959900
Same as above plus superheater percentage1729416920171251216211583
Same as above but substitute firebox area for grate area5535067920572464373541652
Power L12078917668205601715518124
Power MT726.34619.26733.45732.00847.73

Specifications by Steve Llanso of Sweat House Media
ClassP-5P-6P-6/P-7P-8P-9
Locobase ID8666 8667 8668 3290 8669
RailroadTexas & New Orleans (SP)Texas & New Orleans (SP)Southern Pacific (SP)Southern Pacific (SP)Texas & New Orleans (SP)
CountryUSAUSAUSAUSAUSA
Whyte4-6-24-6-24-6-24-6-24-6-2
Number in Class101261512
Road Numbers900-909 / 600-609610-6212453-2458, 2476-24772461-2475622-630, 631-633
GaugeStdStdStdStdStd
Number Built101261512
BuilderBaldwinAlco-BrooksAlco-BrooksBaldwinBaldwin
Year19121913191319211923
Valve GearWalschaertWalschaertWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase13.33'13.33'13.33'13'13'
Engine Wheelbase34.67'35.67'35.67'35.50'35.50'
Ratio of driving wheelbase to overall engine wheebase 0.38 0.37 0.37 0.37 0.37
Overall Wheelbase (engine & tender)75.80'75.80'
Axle Loading (Maximum Weight per Axle)52000 lbs63500 lbs62500 lbs60700 lbs61300 lbs
Weight on Drivers148000 lbs176400 lbs172400 lbs180000 lbs183100 lbs
Engine Weight243700 lbs282500 lbs277300 lbs297800 lbs307300 lbs
Tender Light Weight160800 lbs221900 lbs
Total Engine and Tender Weight404500 lbs529200 lbs
Tender Water Capacity9000 gals12000 gals12000 gals
Tender Fuel Capacity (oil/coal)2940 gals gals gals4000 gals4000 gals
Minimum weight of rail (calculated)82 lb/yard98 lb/yard96 lb/yard100 lb/yard102 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter77"77"77"73.50"73.50"
Boiler Pressure210 psi210 psi200 psi200 psi210 psi
Cylinders (dia x stroke)22" x 28"25" x 28"25" x 28"25" x 30"25" x 30"
Tractive Effort31416 lbs40568 lbs38636 lbs43367 lbs45536 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.71 4.35 4.46 4.15 4.02
Heating Ability
Firebox Area174 sq. ft235 sq. ft235 sq. ft283 sq. ft283 sq. ft
Grate Area49.50 sq. ft70.30 sq. ft70.30 sq. ft70.40 sq. ft70.40 sq. ft
Evaporative Heating Surface2651 sq. ft3953 sq. ft3982 sq. ft3352 sq. ft3352 sq. ft
Superheating Surface550 sq. ft770 sq. ft806 sq. ft867 sq. ft815 sq. ft
Combined Heating Surface3201 sq. ft4723 sq. ft4788 sq. ft4219 sq. ft4167 sq. ft
Evaporative Heating Surface/Cylinder Volume215.19248.49250.32196.66196.66
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1039514763140601408014784
Same as above plus superheater percentage1216217125164501703717741
Same as above but substitute firebox area for grate area4275257246549906848671316
Power L11853220428200251806918266
Power MT828.16765.92768.23663.92659.80

Photos

Reference


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