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

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

Class P-11 (Locobase 8731)

Data from SP 7 - 1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive 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 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 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 collection. 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. Firebox had combustion chamber and the boiler was fitted with feedwater heater; valve travel 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 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 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 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 collection.

Produced in two batches in June 1912 (works #37959-37964 and 37981-37984), this class preceded the slightly larger P-5s that went to the Southern Pacific in August.

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 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 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. 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 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.

Class P-9 (Locobase 8669)

Data from T&NO 3 -1932 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. 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. Compared to the SP's engines, these ran a slightly higher boiler pressure and weighed more.