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.
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.
http://www.ctrc.org/projects/2479-restoration/2479-facts.html, last accessed 16 January 2010. 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 feedwater heaters. In addition, the last 8 had trailing-truck booster engines. See notes on the P-8 design at Locobase 3290.
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 5 road numbers that were altered (2481-2482, 2488-2489, 2491).
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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 11-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. The 14 P-10s delivered in 1923 had feedwater heaters and the last 8 had trailing-truck booster engines, but were otherwise similar to the P-8s. 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.
Baldwin produced these near-sisters of the Espee P-8s (Locobase 3290) in two 1923 batches. Compared to the SP's engines, these ran a slightly higher boiler pressure and weighed more.
|Specifications by Steve Llanso|
|Class||P-1/P-3||P-1/P-3 - superheated||P-10||P-11||P-11 - superheated||P-12||P-13||P-14||P-4||P-5||P-5||P-6||P-6/P-7||P-8||P-9|
|Railroad||Southern Pacific (SP)||Southern Pacific (SP)||Southern Pacific (SP)||El Paso & Southwestern (SP)||El Paso & Southwestern (SP)||El Paso & Southwestern (SP)||Texas & New Orleans (SP)||Southern Pacific (SP)||Southern Pacific (SP)||Southern Pacific (SP)||Texas & New Orleans (SP)||Texas & New Orleans (SP)||Southern Pacific (SP)||Southern Pacific (SP)||Texas & New Orleans (SP)|
|Road Numbers||2400-2437, 2459-2460||2400-2437||2478-2491||140-149 / 3100-3109||140-149 / 3100-3109||3120-3129||631-633||2455-2457||2409-10 14,19, 22, 24, 36||2438-2452||900-909 / 600-609||610-621||2453-2458, 2476-2477||2461-2475||622-630, 631-633|
|Builder||Burnham, Williams & Co||SP||Baldwin||Burnham, Williams & Co||EP & SW||Alco-Brooks||Baldwin||SP||SP||Baldwin||Baldwin||Alco-Brooks||Alco-Brooks||Baldwin||Baldwin|
|Locomotive Length and Weight|
|Ratio of driving wheelbase to overall engine wheebase||0.40||0.40||0.37||0.38||0.38||0.37||0.37||0.37||0.40||0.40||0.38||0.37||0.37||0.37||0.37|
|Overall Wheelbase (engine & tender)||63.02'||63.02'||75.80'||63.98'||64.21'||78.68'||63.02'||75.80'||75.80'|
|Axle Loading (Maximum Weight per Axle)||46000 lbs||48000 lbs||60700 lbs||63100 lbs||65300 lbs||52700 lbs||48300 lbs||52000 lbs||63500 lbs||62500 lbs||60700 lbs||61300 lbs|
|Weight on Drivers||141000 lbs||141000 lbs||180700 lbs||150700 lbs||157500 lbs||189300 lbs||188700 lbs||185400 lbs||155000 lbs||141400 lbs||148000 lbs||176400 lbs||172400 lbs||180000 lbs||183100 lbs|
|Engine Weight||222000 lbs||222000 lbs||300000 lbs||224000 lbs||239500 lbs||309100 lbs||313800 lbs||307500 lbs||265000 lbs||220900 lbs||243700 lbs||282500 lbs||277300 lbs||297800 lbs||307300 lbs|
|Tender Light Weight||162200 lbs||162200 lbs||221900 lbs||146133 lbs||154800 lbs||291100 lbs||138100 lbs||160800 lbs||221900 lbs|
|Total Engine and Tender Weight||384200 lbs||384200 lbs||521900 lbs||370133 lbs||394300 lbs||604900 lbs||359000 lbs||404500 lbs||529200 lbs|
|Tender Water Capacity||12000 gals||7000 gals||7000 gals||16152 gals||7000 gals||9000 gals||12000 gals||12000 gals|
|Tender Fuel Capacity (oil/coal)||4000 gals||14.5 tons||14.5 tons||tons||4912 gals||gals||gals||2940 gals||2940 gals||gals||gals||4000 gals||4000 gals|
|Minimum weight of rail (calculated) on which locomotive could run||78 lb/yard||78 lb/yard||100 lb/yard||84 lb/yard||88 lb/yard||105 lb/yard||105 lb/yard||103 lb/yard||86 lb/yard||79 lb/yard||82 lb/yard||98 lb/yard||96 lb/yard||100 lb/yard||102 lb/yard|
|Geometry Relating to Tractive Effort|
|Boiler Pressure||200 psi||210 psi||200 psi||200 psi||176 psi||205 psi||200 psi||210 psi||210 psi||200 psi||210 psi||210 psi||200 psi||200 psi||210 psi|
|Cylinders (dia x stroke)||22" x 28"||22" x 28"||25" x 30"||22" x 26"||24" x 26"||26" x 28"||25" x 30"||25" x 28"||23" x 28"||22" x 28"||22" x 28"||25" x 28"||25" x 28"||25" x 30"||25" x 30"|
|Tractive Effort||29920 lbs||31416 lbs||43664 lbs||33957 lbs||32947 lbs||45181 lbs||43367 lbs||40306 lbs||34337 lbs||29727 lbs||31416 lbs||40568 lbs||38636 lbs||43367 lbs||45536 lbs|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.71||4.49||4.14||4.44||4.78||4.19||4.35||4.60||4.51||4.76||4.71||4.35||4.46||4.15||4.02|
|Firebox Area||174 sq. ft||178 sq. ft||283 sq. ft||185.40 sq. ft||200.40 sq. ft||225 sq. ft||283 sq. ft||235 sq. ft||178 sq. ft||178 sq. ft||174 sq. ft||235 sq. ft||235 sq. ft||283 sq. ft||283 sq. ft|
|Grate Area||49.50 sq. ft||49.50 sq. ft||70.40 sq. ft||52.20 sq. ft||52.20 sq. ft||70.30 sq. ft||70.50 sq. ft||70.30 sq. ft||49.50 sq. ft||49.50 sq. ft||49.50 sq. ft||70.30 sq. ft||70.30 sq. ft||70.40 sq. ft||70.40 sq. ft|
|Evaporative Heating Surface||3048 sq. ft||2749 sq. ft||3352 sq. ft||3821 sq. ft||2922 sq. ft||4153 sq. ft||3352 sq. ft||3953 sq. ft||2749 sq. ft||2749 sq. ft||2651 sq. ft||3953 sq. ft||3982 sq. ft||3352 sq. ft||3352 sq. ft|
|Superheating Surface||548 sq. ft||815 sq. ft||603 sq. ft||1007 sq. ft||836 sq. ft||770 sq. ft||548 sq. ft||556 sq. ft||550 sq. ft||770 sq. ft||806 sq. ft||838 sq. ft||815 sq. ft|
|Combined Heating Surface||3048 sq. ft||3297 sq. ft||4167 sq. ft||3821 sq. ft||3525 sq. ft||5160 sq. ft||4188 sq. ft||4723 sq. ft||3297 sq. ft||3305 sq. ft||3201 sq. ft||4723 sq. ft||4788 sq. ft||4190 sq. ft||4167 sq. ft|
|Evaporative Heating Surface/Cylinder Volume||247.42||223.15||196.66||334.03||214.64||241.37||196.66||248.49||204.17||223.15||215.19||248.49||250.32||196.66||196.66|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||9900||10395||14080||10440||9187||14412||14100||14763||10395||9900||10395||14763||14060||14080||14784|
|Same as above plus superheater percentage||9900||12162||16896||10440||10749||17294||16920||17125||12162||11583||12162||17125||16450||16896||17741|
|Same as above but substitute firebox area for grate area||34800||43735||67920||37080||41266||55350||67920||57246||43735||41652||42752||57246||54990||67920||71316|