Class 11 (Locobase 12383)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 22, p. 206. Works number was 17363 in January 1900.

The A&NM was formed in 1883 by consolidating the Clifton & Lordsburg and the Clifton & Southern Pacific. When the A&NM converted to standard gauge in 1905, the 11 found a new home at Arizona Copper and later at Phelps Dodge.

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Class 153 (Locobase 8172)

Data from the NWP 10 - 1950 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See the excellent roster on [], access 9 February 2007. Works numbers were 45284-45285 in March 1908. Sources flag the builder's ID of Schenectady as unconfirmed.

This pair of Moguls came as a batch to the NWP in 1908. Especially considering the year in which they were built, these were small 2-6-0s and clearly were built for the particular demands of an undemanding railway. Like much of the NWP's stud, these 2-6-0s operated for the NWP into the 1930s; they were scrapped in 1935.

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Class 16/107 (Locobase 7240)

Data from the SA&AP 6 - 1917 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 14, p. 27. (See Locobase 7235 for a description of this SouthEast Texas railroad.) Works number 8639 was constructed in June 1887 and delivered as August Faltin. The next three were produced in July 1887 as a pair (8655-8656) and went on the road as Richard King and A. C. Jones. George W. Fulton Jr (works 8658) completed the order.

By the time the SA&AP published the diagram book from which the specs are drawn, these Moguls operated as switchers. Produced a half-year after the Moguls described in Locobase 7239, this group was a little bigger. Locobase studied the SA&AP diagram and found that the calculated tube area shown (1,010 sq ft/93.85 sq m) was exactly 121 sq ft too small. This seems to be a math error as the actual calculated tube heating surface area should be 1,175 sq ft (109.15 sq m). He takes the calculated figure, adds 121 sq ft and arrives at the 1,296 sq ft shown in these specs.

All but AC Jones (#18, later #109) were retired by 1917 with 109 lasting another 8 years.

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Class 170 / M-18 (Locobase 7246)

Data from the SA&AP 6 - 1917 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (See Locobase 7235 for a description of this SouthEast Texas railroad.) Works number was 1160 in 1911.

Lima built this single Mogul for the SA&AP, one of the first locomotives from this Ohio builder that was produced for main line service. The SA&AP was absorbed by the Texas & New Orleans, which renumbered the engine 496.

Its service extended only to 1932, even though it was a relatively powerful engine, and it was scrapped on 30 January 1937.

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Class 171/M-19 (Locobase 7247)

Data from the SA&AP 6 - 1917 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 38, p. 247+. (See Locobase 7235 for a description of this SouthEast Texas railroad.) Works numbers were 36725, 36741-36742 in July 1911.

The specs for this trio of oil-burning Moguls have an usual notation in the supplemental instructions: #53 orders "No vanadium in the engine frames" (the first words are underlined). Given the big push for the adoption of vanadium steel that began at around this time, Locobase supposes that its presumed benefits were outweighed for a set of small local freight engines by the extra cost. Perhaps the previous instruction (#52) offered enough guarantee of frame strength: "Frames to be thoroughly annealed, free from flaws and blow holes."

The three engines went to the Texas & New Orleans in 1925, a couple of years before the railroad itself was leased to the T & NO. They were class M-19s for the next two decades. Although 499 was sent to the scrapyard in February 1937, the other two had more railroading to do. The Southern Pacific de Mexico bought them in October 1949 as road numbers 411-412.

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Class 4 / 101 (Locobase 7239)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 12, p.215. Works numbers were 7762, 7764, 7766 in December 1885; 8296-8298 in December 1886.

(See Locobase 7235 for a description of this SouthEast Texas railroad.) This Mogul sextet was delivered as new road freight engines to the SA&AP and each had a name: M Kenedy (sic), Sam Maverick, Charles Hugo, Charles Schreiner, Robert C. Eckhardt, and Edward Muggs. A note at the top of the Baldwin spec page notes that the design used spec 2266 except for the use of a wagon-top boiler.

All but 13 disappeared before 1917; 13 defied any operator's triskadekaphobia and hung on until 1925.

See also the SA&AP 6 - 1917 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. By the time the SA&AP published the diagram book from which the specs are drawn, these Moguls operated as switchers. The boiler was smaller, but the diagram had a mismatch between the likely tube area and the number and count of tubes.

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Class 42 (Locobase 13739)

Data from the SA&AP 6 - 1917 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 113

114

115

116

117

118

119

120

121

122

(See Locobase 7235 for a description of this SouthEast Texas railroad.)

By the time the SA&AP published the diagram book from which the specs are drawn, these Moguls operated as switchers. Locobase suspects that they ran as light freight engines earlier in their careers and in fact they were delivered as new engines in the 1880s.

NB: The figure given in the diagram for the tube heating surface falls far short of the calculated figure given the number, diameter, and length of tubes. Locobase assumes that the given firebox heating surface is correct and has adjusted the EHS from 998 sq ft to 1,179 sq ft accordingly.

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Class 500/168/M-17 (Locobase 7245)

Data from the SA&AP 6 - 1917 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 27, p. 254. Works number was 25770 in May 1905. (See Locobase 7235 for a description of this SouthEast Texas railroad.)

This single Mogul locomotive was delivered to the OR&C, but that railroad already teetered on bankruptcy and sold the 500 to the SA&AP service in 1911. (And, indeed, the OR&C was abandoned in 1917.)

As the 168, the Baldwin served the SA&AP line for decades, even after it was taken over by the Texas & New Orleans (which soon became the Texas & Louisiana lines of the Southern Pacific). Its boiler dimensions changed slightly. Dropping the engine's BP to 190 psi (13.1 bar) seems to preceded increasing driver diameter increased to 58" (1,473 mm). As a result, tractive effort first fell to 27,070 lb (12,279 kg) and decreased to 26,135 lb (11,855 kg) when thicker driver tires were fitted.

495 retired only in 1946, but was sent to the SP del Pacifico in October 1949, which operated it for three more years before scrapping it April 1952.

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Class 52/ 301/0178 (Locobase 8171)

Data from the NWP 10 - 1950 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 13, p. 71.. See the excellent roster on [], access 9 February 2007. Works numbers were 7671-7675 in August 1885; 8059-8062, 8064 in July 1886; 8085, 8089, 8091-8092, 8098 in August.

Compared to other North American 2-6-0s of the middle 1880s, these were some of the smallest and least powerful Moguls to run on the standard gauge. When the first five were ordered on 28 July 1885, their boilers had just 156 tubes and they put only 63,000 lb (28,576 kg) and weighed 76,000 lb (34,473 kg) overall. A December 12 order for another ten made no changes.

The data shown above reflect a later rebuilding, probably by the Santa Fe when that railroad took control of the GC&SF. (This railway is often identified as the Gulf Coast & Santa Fe and may have been so known, but the name seems to have official only for the GC&SF Hospital Association.) The GC&SF was founded by Galveston merchants to provide access from their port to the interior of Texas while skirting the yellow-fever-ridden Houston area. It came under AT&SF control in 1886.

Possibly because they were so small and light, these engines had short careers for the most part. Most of the class remained on the south Texas rails until they were scrapped. 306 and 308 were sent to the ferro-knacker's in 1900, barely fifteen years after they went into service. The last to be scrapped by the Santa Fe was 178 (ex-313, ex-64) in June 1907.

302 (ex-53) was sold to the Kansas City, Mexico & Orient in August 1902 as their #4; it was still in service in 1929. 311 (ex-62) was sold in July 1903 to Lake Creek Lumber of Ulmer, Tex. Later ownership by Saner -Whiteman Lumber of Caro, Tex (a 1908 merger of Saner-Ragley with Whiteman-Decker) was succeeded by a tour with the Lufkin Foundry & Machine Company. Charles A Sims Company bought the 180 (ex-315, ex-66) in September 1902.

In its 40-year career, 314 (ex-65) operated under five different railroad names, starting out as Santa Fe's Gulf, Colorado & Santa Fe (#65) in south central Texas. It was later redesignated as Santa Fe's own #179. After the NorthWestern Pacific was formed with equal shares of Southern Pacific and Santa Fe money, the engine traveled to the Eel River & Eureka (#5) in Northern California, then the San Francisco & Northwestern before winding up as NWP's #152. Its 43-year career came to a close in 1929.

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Class 58/129 (Locobase 7242)

Data from the SA&AP 6 - 1917 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (See Locobase 7235 for a description of this SouthEast Texas railroad.)

This second batch of Rome Moguls had somewhat bigger boilers and were almost exactly the same size as the Baldwins of a few years earlier.

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Class ED/M-63/M-4 (Locobase 9503)

Data from "Southern Pacific Schenectady Mogul," Railway and Locomotive Engineering, April 1899, page 153, 172; "Cooke Mogul for Southern Pacific", May 1899, 216; and "Cooke Moguls for the Southern Pacific", Railway Age, Volume 27 (14 April 1899), p. 281. See also SP Menke All-Time Steam Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange collection.

Cooke supplied the lion's share of this large class of Moguls with Schenectady making up the balance. Works numbers for Cooke engines were 2436-2438 in April 1899, 2439-2440 in May, 2441-2445 in June;

2518-2525 in March 1900, 2526-2531 in April, 2532-2541 in May, 2551-2554 in June, 2555 in July, 2592-2603 in November, 2604-2615 in December,

2616-2621 in January 1901, and 2622-2629 in February

Schenectady works numbers were 4953-4956 in 1899,

5680-5681, 5683-5687 in 1900 road numbers were 1615-1618, 1629-1631, 1673-1674, and 1708-1719.

RA's report credited the former superintendent of motive power H J Small with the design.

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Class EF/M-6 (Locobase 4135)

Data from Baldwin Locomotive Works, Record of Recent Construction ((1903), No. 31, p. 7. See also DeGolyer, Volume 24, pp. 83+ and Volume 25, p.3. See also "Mogul Freight Locomotives for the Southern Pacific", Railroad Gazette, Volume 33, No. 48 (29 November 1901), p. 821. (Many thanks to Ellis Tammeleo's group for creating the "October 2022" Google doc with a series of corrections and questions about Locobase's information, including this entry.) Works numbers were 20388-20389, 20419-20420, 20436, 20464-20466, 20500-20501, 20573, 20591, 20622, 20647-20648, 20670-20673, 22284, 22289, 22297, 22304, 22321-22322, 22333. 22346, 22371, 22385, 22400, 22414, 22425, 22431..

According to the Louisiana Rail Site ([]), 68 of this Vauclain compound class were delivered to the SP in 1901. 23 more were added in 1902-1903, with four identical engines going to subsidiary Texas & New Orleans in 1903.

Locobase is surprised by just how far apart the specification estimates were from those given in the Record of Recent Construction. Estimated adhesion weight was given as 115,000 lb (52,163 kg), but the Recent Construction figure shown in Locobase's own specs nearly matches the estimated engine weight of 147,000 lb (66,678 kg). The actual engine weight was just shy of ten tons heavier than the estimate. The later order raised the estimated adhesion weight to 127,000 lb (57,606 kg).

The class was soon simpled (1907-1914) and shortly thereafter superheated; see Locobase 8718.

Several were simpled in 1912 with 22 x 28 cylinders. These were later (1919) equipped with a superheater and had their boiler pressure raised to 200 psi.

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Class EG / M-63 / M-9 (Locobase 13532)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 33, p. 258. Works numbers were 33779-33780, 33793-33794 in September 1909.

This quartet of oil-burners repeated the Alco design shown in Locobase 11186, but increased cylinder diameter by an inch. The Espee like Moguls and bought them from several builders and in several sizes.

1820 remained with the Espee until the end of its working days in May 1950. The other three were leased to the SP de Mexico in January 1924 , where they operated until the parent company reclaimed them in late-1941, early-1942. The end of the war and of steam saw 1819 and 1821sold to the Pacifico in Mexico in December 1951. 1822 was scrapped in October 1953.

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Class M-10 (Locobase 8662)

Data from T&NO 3 -1932 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 42, pp. 31+.

Among the many classes of Moguls was this set delivered as simple-expansion locomotives to the T & NO (500-509 / works numbers 37896-37900 & 37937-37941) and the Houston & Texas Central (510-514 / works numbers 37971-37975). The class was fitted with superheaters during production and were delivered with 12" (305 mm) piston valves. Two of the class received feed water heaters in a later shop visit.

The DeGolyer specification includes a reference to the use of Vauclain's "diamond seam" pattern for all horizontal boiler seams. See Locobase 5340 for a discussion of this pattern as used in all of the Harriman Common Standard locomotives.

The T&NO diagram book gave a different, lower superheater area of 373 sq ft (34.65 sq m) and higher adhesion weights of 152,000 lb plain, 155,000 lb when fitted with a feedwater heater.

Like the other 2-6-0s in the SP system, these had long working lives before heading to the scrapyard between June 1952 and January 1957.

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Class M-11 (Locobase 8663)

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

Superheated like so many other SP Lines Moguls, this class had larger fireboxes than the M-9 ( Locobase 8661) and weighed a bit more, but were otherwise identical. Locobase believes that the original wide (96") firebox was replaced in favor of the then-standard boiler.

They had been assigned to the Cananea Rio Yaqui & Pacific (Locobase 13534), sold to the Southern Pacific of Mexico or the FC del Pacifico, then to the Houston & Texas Central -- all before the end of 1912.

(Others went to the Arizona Eastern by a similar route; see Locobase 8664 for their superheated upgrades.)

Like the other 2-6-0s, these served into the late 1940s-early 1950s.

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Class M-11 (Locobase 8664)

Data from T&NO 3 -1932 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 33817, 33823, 33831-33837 in September 1909; 33878-33880, 33915-33917 in October.

These Moguls were carried briefly on the SPdeM roster (see Locobase 13534). Six of the engines soon went to the Arizona Eastern (516, 520, 524, 527-529) in 1912.

They were later superheated, at which point Locobase believes that the original wide (96") firebox was replaced in favor of the then-standard boiler. In November 1924, all of them were sold to the parent Southern Pacific and reclassified M-9 or M-11.

Like the other 2-6-0s, these served late into the steam era before being scrapped in 1952-1956.

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Class M-14 (Locobase 7241)

Data from the SA&AP 6 - 1917 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works #383, 392 in 1888, 525-526 in 1890.

(See Locobase 7235 for a description of this SouthEast Texas railroad.)

By the time the SA & AP published the diagram book from which the specs are drawn, these Moguls operated as switchers. Locobase suspects that they ran as light freight engines earlier in their careers and in fact they were delivered as new engines in the 1880s.

NB: The figure given in the diagram for the tube heating surface falls far short of the calculated figure given the number and length of tubes. Locobase assumes that the tube diameter was 2" and thus has adjusted the EHS accordingly.

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Class M-21 (Locobase 1401)

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

Very interesting set of home-built Moguls that preserved many of the dimensions of the standard Espee 2-6-0, but took liberties in other areas. One change was an increase in boiler pressure by 35 psi. Another difference was a wider grate that contributed to a considerable gain in direct heating surface. The tubes and flues were 8" (203 mm)shorter, but there were more of each. Naturally all of this led to a heavier engine with mainline axle loadings. In fact they may have had the highest adhesion weight of any 2-6-0 ever built.

Described by Linn Wescott (Model Railroad Steam Locomotive Cyclopedia, Vol 1 -- 1960) as "very powerful for their type, but also very heavy ...When they were retired in favor of diesels, it was partly because they were too heavy to be sent to branchline service."

The first three were completed without feedwater heaters and weighed 4,000 lb less. Otherwise all were identical and, except for 525, which was scrapped in 1949, served until the mid-1950s.

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Class M-4 (Locobase 8717)

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

Locobase notes this large Mogul class originally delivered to the Galveston, Harrisburg & San Antonio by Schenectady (works numbers 4957-4964 in 1899; 5678-5679, and 5682 in 1900/road numbers 410-417, 446-447, 452) and Cooke (2456-2460, 2477 in 1899; 2542-2547, 2598-2601

418-445, 448-459).

Other subsidiaries increased the total for the design to 103. Some were completed with "heavy frames" and had fireboxes with 156 sq ft (14.49 sq m) of heating surface area.

In the 1920s, the T&NO's own shops updated the class with a modest amount of superheater; see Locobase 7281.

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Class M-4 - superheated (Locobase 7281)

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

Delivered to several SP family subsidiaries in 1899 (Locobase 8717), these Moguls were clearly satisfactory.

In the 1920s, the T & NO's own shops updated the class with a modest amount of superheater. They weren't especially light on the rails, but their adhesion and tractive power put these 2-6-0s on the line right to the end of steam.

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Class M-4 - superheated (Locobase 13309)

Data from SP Menke All-Time Steam Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Locobase 9503 shows the saturated-boiler of this widely distributed Mogul and Locobase 7281 describes the very similar upgrade administered to its own engines by Espee subsidiary Texas & New Orleans. Espee owned "heavy-frame" and "light-frame" M-4 Moguls. The specifications above refer to the heavy-frame upgrade; light-frame M-4s weighed 128,000 lb on the drivers, 149,000 lb on the engine. Espee diagrams show at least two slightly different superheater areas. The smaller value is 252 sq ft.

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Class M-44 (Locobase 8760)

Data from SP Menke All-Time Steam Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 10, p. 206. Works number was 5649 in May 1881.

Locobase 8759 shows the 12's stable mate on the Nevada & California. The N&C entered receivership and its assets were taken over by the North Shore Railroad, which quickly evolved into the South Pacific Coast RR in 1906.

At some point, the two locomotives were treated slightly differently during mid-life updates with the 12 winding up with seven fewer tubes than the 11.

The SPC rebuilt this engine (along with the #11) as 4-6-0 Ten-wheelers in 1921.

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Class M-48 (Locobase 8759)

Data from SP Menke All-Time Steam Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Vol 10, p. 206. Works number was 5649 in May 1881.

This slim-gauge Mogul (and the Mogul shown in Locobase 8760) went to the Nevada & California, which was established on the East Bay of San Francisco Bay in 1884 as the successor to the California & Mount Diablo Railroad. Of the two locomotives, this one had the boiler most like the one fitted to the pair when they were originally built. According to the DeGolyer specification book, the locomotives had 138 2" (51 mm) tubes, each measuring 8.25 long (2.51 m) and rolled on 43" (1,092 mm) drivers.

The N&C entered receivership in 1893 and its assets were taken over by the North Shore Railroad, which quickly evolved into the South Pacific Coast RR in 1906. It may be that, unlike the M-48, this engine remained relatively unchanged by its update.

Both engines were rebuilt by the SPC as 4-6-0s in December 1921.

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Class M-6a/M-8 (Locobase 8719)

Data from SP Menke All-Time Steam Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Locobase 4135 shows this class when it was delivered in 1901 and 8718 shows one version of the superheater upgrade given to this class beginning in 1919. The present record shows a larger boiler with a bit more superheat grafted to the same firebox. Menke's book includes the M-8 (Locobase 4136) and 1770-1779 (Locobase 4135) with the same data

Retirements began in 1934 and continued until 1958.

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Class M-6b/M-6c (Locobase 8718)

Data from SP Menke All-Time Steam Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Many thanks to Ellis Tammeleo's group for creating the "October 2022" Google doc with a series of corrections and questions about Locobase's information, including this entry.)

Locobase 4135 shows this class when it was delivered in 1901 as four-cylinder compounds with saturated boilers.

Retirements began in 1934 and continued until 1958.

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Class M-6s (Locobase 7282)

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

Delivered as Vauclain compounds to the Espee and the T&NO (its subsidiary) -- see Locobase 4135 -- this class was simpled in 1912 with 22 x 28 cylinders. A further refinement saw the cylinder diameter bushed to 21", but a superheater added. Compared to the M-4 superheating program undertaken at around the same time (see Locobase 7281), the M-6s lost still more heating surface, but gained more superheater area.

Relatively light on the rails, many of the Moguls were kept in service for decades. Retirements began in 1934 and continued until 1958.

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Class M-7 (Locobase 4136)

Data from Baldwin Locomotive Works, Record of Recent Construction ((1903), No. 32, p. 130-131. See also DeGolyer, Volume 24, p. 89. See also "Mogul Freight Locomotives for the Southern Pacific", Railroad Gazette, Volume 33, No. 48 (29 November 1901), p. 821. Works numbers were 19532-19536 in September 1901.

Five of the large class of Vauclain compound Moguls described in Locobase 4135 were equipped with Vanderbilt boilers 16-20 (see New York Central's E-3s, Locobase 4141). Its corrugated construction was meant to eliminated the troublesome and numerous boiler stays.

Like most diversions from the conventional design in steam locomotives, however, this innovation and the Vauclain compound system proved more trouble than their promised worth. All were converted to simple expansion in 1907-1909 and had their Vanderbilt boilers replaced with conventional vessels in 1913-1914.

Superheating the class came in 1919; see Locobase 8719.

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Class M-9 (Locobase 16590)

Data from "Engines for the Associated Lines," Railway and Locomotive Engineering, Vol 21, No 12 (December 1908), p. 524-525. Works numbers were 45020-45034 in February 1908.

This entry describes the other fifteen of the 30 Moguls the Dunkirk, NY builder supplied to Southern Pacific railroad in a single 30-engine order. (See Locobase 11186 for the Cananea, Rio Yaqui & Pacific engines.) Relatively large and modern, the low-drivered class used piston valves for their steam admission.

Unlike the CRY&P engines, these went directly to the parent company. Sometime later, the Espee's shops installed superheaters; see Locobase 8720.

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Class M-9 - 1819 (Locobase 13533)

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

Most of the Southern Pacific's M-9 Moguls were delivered with saturated boilers and all were updated with the same superheater outfit. This foursome was originally produced by Baldwin in 1909 (Locobase 13532). Of middling size in terms of tube count, the class retained their oil burners and were otherwise unaltered by their conversion to dry steaming.

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Class M-9 - 1826 (Locobase 8721)

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

Although this pair was identical in many respects to the Brooks-built M-9s, they were built in the Espee's, Sacramento shops. For some reason, when they were superheated, the shops took out 16 more small tubes, which reduced the evaporative heating surface area by more than 100 sq ft.

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Class M-9b (Locobase 8722)

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

The last three of the M-9 class were supplied by Alco-Brooks and went to the Cananea, Yacqui & Pacifico originally, ran under the Southern Pacific de Mexico's name when it took over the CY & P, then to the Arizona Eastern, and finally landed on the Southern Pacific itself.

At some point, the three were superheated with more tubes than the more numerous M-9a variant. All three served the SP for decades before being scrapped in 1950-1954.

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Class M-9s (Locobase 8720)

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

These Moguls were originally built by the Brooks Works of the American Locomotive Company in 1908 (Locobase 16590) as part of a 30-locomotive order.

The T&NO had seven more of its own (see Locobase 8661). Like the T&NO engines, these were superheated beginning in the late 'teens. Although the tube and flue counts, diameters, and lengths were identical, the SP locomotives were credited with more firebox heating surface.

Relatively light on the rails, many of the Moguls were kept in service for decades. Three--1804-1805 and 1807--were leased to the Southern Pacific de Mexico in January 1924 and returned in 1941-1942. 1805 quickly went to Pacific Electric where it operated until April 1947.

Except for the 1818, which was scrapped in January 1936, all of the class remained on the roster into the 1950s.

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Class M-9s-ex-CRY&P (Locobase 8661)

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

These were originally built by the Brooks Works of the American Locomotive Company in 1908 for the Mexican railway Cananea, Yacqui River & Pacifico (Locobase 11126). Once taken into the Houston & Texas Central, the shops bored out their 20" (533 mm) diameter cylinders to match most other SP Moguls and later superheated them. Compared to the M-6, however, the M-9 retained more of the small tubes. (Other M-9 conversions retained the 210-psi working pressure.)

Three of the seven in the 550-556 batch were later fitted with feed water heaters.

Relatively light on the rails, many of the Moguls were kept in service for decades. Retirements began in 1934 and continued until 1958.