Class 684 / L4-c (Locobase 12270)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Vol 21, p. 171. Works numbers were 115766-15770 in February 1898; 15796-15800, 15817-15821 in March; and 15822-15826 in April.

Gene Connelly's notes help us to see that these Consolidations were considered underpowered not too long after they arrived. Beginning in 1902, the class was upgraded with 21" HP and 33" LP cylinders. (It isn't clear if the stroke was changed.)

After another 6 years, the CP again recast the locomotives, removing the front truck and installing two 20" x 24" simple-expansion cylinders. Designated V1-a 0-8-0s, the class switched for the railway until the 1930s and 1940s.

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Class 71 (Locobase 16578)

Data from "Railway Rolling Stock Orders and Deliveries", Canadian Railway and Marine World" (October 1926), pp.528D. See also "Lacombe and North Western Railway" in the Atlas of Alberta Railways online at [] and []; and "Lacombe and Blindman Valley Electric Railway" on the Forth Junction Project website at [], both last accessed 21 February 2022. Works number was 1794 in 1926.

Although relatively small, this short-line Consolidation offered both useful superheater area and an Elexco feed water heater in addition to arch tubes. Its road number belies its likely role as the only tender engine to serve the L&NW.

The L&NW was owned by the Alberta provincial government. It originally took form in 1909 as the Lacombe & Blindman Valley Electric Railway, an interurban line. "The railway would serve," notes the Atlas, "a well settled, fertile and productive agricultural area" some 50-70 miles (80.5-112.7 km) south of Edmonton as it ran from Lacombe through Bentley to Rimbey.

Delays and World War I slowed progress with Rimbey being reached only in 1919. Ultimately the railway described a 37-mile (60 km) backwards C west from Lacombe then north then east to Leduc. Forth Junction Project's biography notes he provincial government "assumed control of the line in 1918 and it was reorganized as the Lacombe and Northwestern Railway".

Its motive power originally consisted of an unreliable petrol-hydraulic car and a litle 0-4-0T that hauled a flatcar and a passenger-mail combine. FJP adds "The tiny engine was nicknamed "the Peanut" and the line came to be known as the Peanut Line or the Peanut Special."

Both sources are mute on the acquisition and use of its 2-8-0.

After years of losses, the company was sold to the Canadian Pacific as the Hoadley Subdivision.

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Class 732 / L-5a (Locobase 12323)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Vol 21, p. 171. Works numbers were 16459-16465 in January 1899.

The cylinders dimensions were nominally 20" x 26", but the specs note that the cylinders heads and covers were to be sized for 21" cylinders and the the 20" cylinders were to be bored out to 21".

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Class C-1 / N4a (Locobase 4939)

Data from [], which credits Dale Wilson's book Algoma Eastern Railway (Nickel Plate Rails, 1977). Additional information from CP 2 - 1947 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Curiously, 52, which was delivered 5 months after Mogul M-1, has the next lowest builder's number (51182).

According to the 1947 book, 3952 - the lone C1 -- had a Vaughan & Horsey superheater of suprisingly meager dimensions. By the time of the 1947 diagram, the firebox heating surface area included 25 sq ft (2.3 sq m) of arch tubes.

After the CP took over the AER in 1930, these enginers were renumbered 3952-3956 and served until 1955.

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Class C-2 / N4b (Locobase 4940)

Data from [], which credits Dale Wilson's book Algoma Eastern Railway (Nickel Plate Rails, 1977). Additional information from CP 2 - 1947 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 1351-1352 in 1916.

These two engines slightly reduced the cylinder size compared to this line's C-1 Consolidation (Locobase 4939), but upped the boiler pressure. By the time of the 1947 diagram, the firebox heating surface area included 26 sq ft (2.35 sq m) of arch tubes.

After the CP took over the AER in 1930, 53 added 3900 to become 3953 and ran until 1956. 54 became 3954 and ran until 1958.

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Class C-3/N4c, d (Locobase 4941)

Data from [], which credits Dale Wilson's book Algoma Eastern Railway (Nickel Plate Rails, 1977). Additional information from CP 2 - 1947 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 62598-62599 in April 1921.

Considerably bigger than earlier AER Consolidations, these bore more heavily on the track as well. They had a smaller boiler in relation to cylinder volume, but much more superheating surface area and a larger firebox. By the time of the 1947 diagram, the firebox heating surface area included 27 sq ft (2.3 sq m) of arch tubes.

In 1930, when the Canadian Pacific leased the Algoma Eastern for 999 years, these two were renumbered 3955-56. Both carried on with the CP until 1957.

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Class L2a (Locobase 15769)

Data from CP 1911-24 supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange, and DeGolyer, Vol 18, p. 100. Works numbers were 13037-13038 in November 1892 for the simple-expansion locomotives. Six others (works numbers 13040, 13053 in November 1892, , 13224, 13227, 13252, 13257 in February 1893) were delivered as Vauclain compounds.

Although these Consolidations are listed under the Canadian Pacific herald, they didn't actually arrive until 1898. They were sold to the Toledo, Ann Arbor & Northern Michigan as their 37-38. (Six more Vauclain compounds are shown in Locobase 15770.) The entire class was repossessed by Post Martin within two years and leased to the Norfolk & Western, where they briefly bore the numbers 8-15. Locomotive reseller New York Equipment bought them from Post Martin in 1896 and found a buyer in the CPR two years later.

The data show the later boiler, which replaced the one holding 186 2 1/4" tubes. 3110 was scrapped in 1919, 3111 a decade later in 1929.

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Class L2b (Locobase 15770)

Data from CP 1911-24 supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange, and DeGolyer, Vol 18, p. 100. Works numbers were 13040, 13053 in November 1892 and 13224, 13227, 13252, 13257 in February 1893.

As noted in Locobase 15769, the CPR was these locomotives' third owner, but the first two were temporary. In addition to two simple-expansion engines sold to the Toledo, Ann Arbor & Northern Michigan, Baldwin supplied these six were Vauclain compounds powered by two 13" (330 mm) HP cylinders and two 22" (559 mm) LP cylinders.

The entire class was repossessed by Post Martin within two years and leased to the Norfolk & Western, where they briefly bore the numbers 8-15. Locomotive reseller New York Equipment bought them from Post Martin in 1896 and found a buyer in the CPR two years later.

The data show the later boiler, which replaced the one holding 186 2 1/4" tubes. Locobase can't pin down just when the original, quite puny set of cylinders was replaced by the Pittsburgh cross-compound system used in all other CPR compounds, but figures that no-one but the CPR ever owned the engines long enough to care to invest that much effort.

1314 and 1316 were sent to the scrapper in March 1914. The others remained in service into the 1920s.

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Class L2c (Locobase 15768)

Data from CP 1911-24 supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange, and DeGolyer, Vol 13, p. 54. Works numbers were 7434, 7444 in September 1884 and 7976, 7975 in June 1886.

Big and powerful for their time, these Consolidations aroused some anxiety if the notes in the specifications for the 1886 pair are any guide. One entry admonished "Corners of fire box to be carefully fitted to ensure tight joint, sheets to run longer and better scarfs than last engines (the two from 1884). Pay special attention to this (underlined)."

Under the weight entries (which aren't filled in), a note pleads "Increase weight as much as possible by any available means." The entry went on to note the width and height limits (9' 9", 15' 6"/2.97 m, 4.72 m, respectively) and the demands that prompted the advisory: "Grade of 232 feet [4.4%] combined with curves of 10 degrees; to haul 6 Pullman cars--160 gross tons."

When delivered the boiler had 206 2 1/4" tubes (57 mm), but by 1911, that vessel had been replaced with one holding 237 of the smaller tubes. The firebox's dimensions remained unchanged.

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Class L2d (Locobase 15771)

Data from CP 1911-24 supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange. Works number was 1062 in 1887.

This single Consolidation had modest power and dimensions, but was sturdy enough to be sold forty years after its manufacture to the Manitoba Saskatchewan Coal Company in March 1927. How much of the original locomotive was left is difficult to say.

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Class L3a (Locobase 15772)

Data from CP 1911-24 supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 1210 in 1896, 1225-1226 in 1897.

The CPR produced five low-drivered Consolidations in the late 1890s. This trio had the smaller of the two driver diameters. (The other two appear in Locobase 15773.) After long careers with the CPR, they were leased in 1923 to subsidiary Esquimalt & Nanaimo as their 30-32, which bought the locomotives outright in 1930. The first two were scrapped in 1924, the last in 1935.

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Class L3b (Locobase 15773)

Data from CP 1911-24 supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 1252-1253 in 1898.

Locobase 15773 shows the first three low-drivered Consolidations turned out by the CPR in the late 1890s. The current pair shows the taller of the two driver diameters fitted to these engines.

Like the first three, the 3133-3134 were leased in 1923 to subsidiary Esquimalt & Nanaimo. The 3133 was scrapped in , the 3134 in 1929.

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Class M1-superheated (Locobase 15776)

Data from CP 1911-24 Locomotive Diagrams supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange.

In the general push to install superheaters in virtually all Canadian Pacific locomotives of any size or recency, these Consolidations were not forgotten. They were delivered in 1898-1899 as Richmond compounds, soon simpled with two 20" x 26" cylinders, and then fitted with the Vaughan & Horsey superheater.

In 1917, eight of the 18 M1a and one M1e lost their front trucks, were redesignated V2a and V2b 0-8-0s, and renumbered in the 6866-6874 range. 3235 was leased to subsidiary Kettle Valley in June 1916 and returned 19 years later. The 3241 was sent to the Esquimalt & Nanaimo in 1928.

There was no one period during which all of the M1s were withdrawn. Possibly because they remained useful light Consolidations, the class made their ways to the ferro-knacker one by one. 3215 was scrapped in June 1921, but 3214 operated right through World War II before being cut up in December 1946.

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Class M1b (Locobase 15775)

Data from CP 1911-24 Locomotive Diagrams supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange. CPR works numbers were 1285-1286 in June and July 1899.

This pair of Consolidations was delivered at the end of the CPR's run of M1a compound 2-8-0s. Within a few years, the rest of the M1 stud would adopt the same cylinder setup and still later all but two would be superheated (see Locobase 15776).

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Class M2a, b, c, d - superheated (Locobase 15663)

Data from CP 1911 - 24 Locomotive Diagrams supplied in August 1913 by Allen Stanley from his extensive Rail Data Exchange.

Not long after these cross-compounds arrived on the CP (Locobase 14157), they were converted to simple expansion and superheated.

Most of the class was scrapped in the 1930s, but 3258 served through World War II. The Esquimalt & Nanaimo operated three of these engines beginning in 1928 (3277 and 3281) and 1929 (3266). They were retired in February 1945 (3277), September 1946 (3266), and December 1946 (3281).

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Class M2e, f - superheated (Locobase 15665)

Data from CP 1911 - 24 Locomotive Diagrams supplied in August 1913 by Allen Stanley from his extensive Rail Data Exchange.

Compared to the superheated M2a-M2d shown in Locobase 15563, these Consolidations sacrificed even more small tubes to fit two more large flues and thus enlarge the superheater area.

All of the M2e and M2f remaining in CPR service were scrapped in in the late 1920s and into the 1930s. Three M2f--3300-3302--were sold to the Quebec Central in 1917 and served for another two decades before they were scrapped in 1939.

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Class M3a - simpled/M3b (Locobase 15779)

Data from CP 1911-24 Locomotive Diagrams supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange.

Locobase 4083 shows the original cross-compounds that came from Schenectady in 1900-1902. As H H Vaughan quickly developed his expertise in superheating, any interest in compounding dwindled. The cross-compound arrangement was removed in favor of two simple-expansion cylinders. The first to be so modified was the class leader 1550 in March 1907. Little else changed.

Before too much longer, conversion to a superheated boiler led to the specs shown in Locobase 15780.

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Class M3a, M3b-superheated (Locobase 15780)

Data from CP 1911-24 Locomotive Diagrams supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange.

Soon after the cross-compound arrangement was removed from these engines in favor of two simple-expansion cylinders (Locobase 15779), the CPR's shops performed further surgery to install a superheater. One of the class was fitted with 21" cylinders and redesignated M3c.

With a few exceptions, the M3b were scrapped in the 1930s. Eight served the CPR during World War Two. 3358 and 3368 endured until August 1943, 3362 was cut up in May 1949 and 3380 in December 1949, 3360 and 3390 were dismantled in November 1952, 3379 and 3387 survived until August 1960

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Class M4a, c (Locobase 4516)

Data from a table in the July 1907 American Engineer and Railroad Journal. Additional data from CP 1911-24 Locomotive Diagram supplied in August 2013 and 1947 Canadian Pacific Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also "Vaughan-Horsey Superheater", American Engineer and Railroad Journal, Volume 80, No 2 (February 1906), pp 41-44. Montreal works numbers were 29863-29873 in 1904; Canadian Locomotive Company works numbers were 629-638 in 1904.

This set was the first of the 57" driver Consolidations introduced in the early years of the 20th Century. They were all delivered with superheaters, but this group differed in having 22 elements rather than the 24 that would be used shortly afterward.

The class proved surprisingly long-lived. All of the MLW batch survived World War Two, being scrapped in 1945 (1), 1946 (1), 1951 (1), 1955 (4), 1957 (2), and 1959 (#3408). Four of the CLCs were scrapped in the 1930s: 1937 (2) and one each in 1938 and 1939. The next to go was 3413 in September 1946. Each of the last four was scrapped in a different year: 1952,

1957, 1958, and 1959 (#3415).

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Class M4b, d (Locobase 5373)

Data from a table in the July 1906 American Engineer and Railroad Journal (AERJ), p. 226; supplemented by CP1911-24 Locomotive Diagrams supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange. See also "Equipment and Supplies", The Railway Age, Vol 38, No 6 (14 October 1904), p. 565. Schenectady works numbers were 30273-30292 in 1904.

The order described in the Railway Age said that the Alco company Consolidations would be fitted with the Schenectady variant of the smoke tube superheater.

Two were sold to the Quebec Central in September 1918 (3424, 3426, renumbered 52-53) and one in June 1920 (3427, renumbered 55). 53 was scrapped in August 1951 and the other two in March 1959. The other 17 also served past the end of World War Two, although 3436 was scrapped in August 1945. Two others were scrapped in the 1940s (3430-3431), eleven in the 1950s, 3440 in 1960, and 3422 and 3429 in 1961.

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Class M4e (Locobase 15781)

Data from CP 1911-24 Locomotive Diagram supplied in August 2013 and 1947 Canadian Pacific Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also "Vaughan-Horsey Superheater", American Engineer and Railroad Journal, Volume 80, No 2 (February 1906), pp 41-44. Montreal works numbers were 1458-1467 in 1906.

Locobase 4516 shows the earlier M4s procured in 1904. The chief difference between the two batches was an inch-and-a-half (38 mm) difference in the cylinder diameter.

See Locobase 5352 for a detailed description of Henry Vaughan's variant of the Schmidt superheater.

As this batch began service, AE&RJ pointed out the most significant difference between the CP V-H firetube superheater and the other Schmidt variants, which lay in how the "small tubes" (i.e. superheater elements) were seaparated from the headers. Locobase quotes the long paragraph in full, breaking it into three paragraphs for readability:

"The main difference between this superheater and other types is that the headers are entirely independent and any pair of the smaller tubes may easily be removed and replaced without disturbing the others. The headers containing the saturated and superheated steam being entirely separate from each other, there is no tendency for the superheated steam to be cooled off by the saturated steam. In case it should be necessary to remove the small superheater tubes, or do some work on the large tubes at the front end, it is only necessary to loosen the union nuts and withdraw the small tubes.

"In case an accident happens to one of the small tubes on the road, it can readily be removed and a blind union or cap placed on the fitting. This can be done in a few minutes and the capacity and efficiency of the superheater is only slightly effected by the loss of a pair of tubes. The 5-in. superheater fire tube, 4% in. inside diameter, is swaged down to 31/2 ins. inside diameter for a distance of about 5 ins. at the back end, is threaded and screwed through the back tube sheet and beaded over. At the front tube sheet it is expanded to 54 ins. outside diameter and is beaded over.

"The damper which controls the flow of hot gases through the superheater tubes is operated by a piston working in a 14-in. diameter cylinder which takes steam from the steam chest. When the engine is taking steam, the damper is forced open, but when no steam is being used a counter weight closes the damper and prevents the hot gases from injuring the superheater tubes. The light steel plate which is placed in front of the end of the superheater tubes to shut them off from the rest of the smokebox is made in three or more sections and may easily be removed, giving access to all joints, in case it is desired to inspect the superheater."

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Class M4f (Locobase 15783)

Data from CP 1911-24 Locomotive Diagram supplied in August 2013 and 1947 Canadian Pacific Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. CPR works numbers were 1467-1476 in 1906.

Although grouped with the other 58" Consolidations, this ten-locomotive variant adopted a larger grate. Grates of similar size were used in the N-series of 63"-driver Consolidations as well as several series of Ten-wheelers.

Except for the 3451, which was scrapped in August 1936 and 3459, which went in January 1939, all of the class served through World War Two. Two--3452 and 3457--were scrapped in May and June 1946, respectively. The others went from late 1949 to late 1956.

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Class M4g, h (Locobase 15782)

Data from a table in the July 1906 American Engineer and Railroad Journal (AERJ), p. 226; and CP 1911-1924 Locomotive Diagrams supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange collection. CPR works numbers were 1510-1519 in 1907. Montreal works numbers 42127-42146 and 43094-43108 in 1907, 45584-45593 in 1908. CPR delivered road numbers 1741-1763 in 1909, and 1764-1765 in 1910.

This set of Consolidations finished the later M4 classes fitted with the 24-flue Vaughn-Horsey superheater. Although completed with plain fireboxes, the class would later be fitted with 25 sq ft (2.32 sq m) of arch tubes at the same time the small tube count dropped by six to 234. The resulting heating surface areas were: direct 190 sq ft (17.65 sq m), evaporative 2,363sq ft (219.53 sq m) to which a smaller superheater added 339 sq ft (31.49 sq m) and brought combined heating surface area to 2,702 sq ft (251.02 sq m).

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Class N2a - "T-bolt" - 141 tubes+ (Locobase 15786)

Data from 1947 Canadian Pacific Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

The main N2 entry at Locobase 4525 shows the variation of upgrade to N3 Consolidations that appeared in the greatest number. This is one of two sub-classes in which the tubes' slightly greater length compared to most N2 installations suggest that they were joined to a "T-bolt" header. This layout differed from the other T-bolt version shown in Locobase 15785 in using the mixed set of 141 2 1/4" tubes and 24 2" tubes found in the main upgrade.

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Class N2a - T-bolt 165 tubes (Locobase 15785)

Data from 1947 Canadian Pacific Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Locobase 4525 is the main entry for this large class of updated N3 Consolidations. The 1947 diagram book shows that all N2s had the same firebox as well as the same power dimensions. Some had the greater number of tubes shown in this entry; Locobase hasn't been able to determine how many were so configured.

The tubes' slightly greater length compared to most N2 installations suggest that they were joined to a "T-bolt" header.

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Class N2a, b, c - "Thru-bolt" header (Locobase 4525)

[] (23 July 1923) for areas, cylinder dimensions, confirmed by data from 1947 Canadian Pacific Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Originally delivered as the N3 class (3800-3960) over a five-year period (see Locobase 15764). These had the Vaughan-Horsey variant of Schmidt's firetube superheater and 23 1/2" cylinders. As will be seen in the comments below, at least one engineer considered the design a mismatch of boiler and firebox capacity and the power generator's demands.

Two other N2a subvariants are shown in Locobases 15785-15786.

This is the main record, which uses the specifications for the N2b and N2c; some N2a also had this configuration. Retrofitting the N3s concentrated on the N3a first and almost all of these were completed by the end of 1927. N3b makeovers began in 1926 with the last finishing in September 1930. N3c were updated beginning in February 1926 and ending in December 1929.

(See Locobase 5306 for an explanation of the difference between a T-bolt and a thru-bolt header.) All had 165 boiler tubes, but most subdivided that total into 141 2 1/4" tubes and 24 2" tubes. The evaporative heating surface area shown here is for all 165 tubes taken together.

By 1950, the following engines had been converted to burn oil:

24 N2a: 3600-3602, 3604, 3609, 3611, 3614, 3616-3617, 3619, 3626, 3629-3630, 3636, 3650, 3657, 3659, 3661, 3663, 3671, 3676-3678, 3690.

12 N2b: 3691, 3695, 3699, 3708, 3712, 3720-3721, 3723, 3730-3731, 3734, 3740

4 N2c: 3741-3741, 3746-3747.

In commenting on the challenge of firing the D10 4-6-0s, Bill Yeats, in his article "My First Trip as the Engineer"' on the West Coast Railway Association's website [] (3 Dec 2004), says of the N2 class: "I might add that the N2 class 36 and 37 hundred consolidation engines were even harder to fire [than the Mbecause they had about the same sized boiler with the same shallow firebox but were supplying superheated steam to larger cylinders with a longer piston stroke."

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Class N3a, b, c (Locobase 15764)

Data from "Consolidation Locomotive With Superheater", American Engineer and Railroad Journal, Volume 83, No 10 (November 1909), pp 425-432; "Canadian Pacific Consolidation Engine," Railway Journal (May 1910), pp.19-21; and CP 1911-24 Locomotive Diagrams supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Chris Hohl for his 24 July 2023 email correcting the valve gear and noting the tender's coal capacity.) Works numbers were:

N3a

Road numbers Builder Works numbers Date

1850 Canadian Pacific 1909

1851-1885 Montreal Locomotive Works 48339-48348, 48869-48883,

48937-48946 1910

1820-1839 Canadian Locomotive Co. 985-1004 1911

1841-1850 MLW 49689-49698 1911

1810-1819 MLW 50237-50246 1911

1800-1809, 1886-1890 MLW 50339-50353 1911

H H Vaughan rolled out the lead engine in 1909 with 24" x 32" cylinders as he sought a balance between power (the large cylinders) and higher average speed (the taller drivers). But operational experiemnce must have convinced him that even with relatively tall drivers, the boiler and grate were overmatched by the demand. So production engines were delivered with 23 1/2" cylinders as shown.

The N3b and N3c subtypes were identical to the N3a, but fitted with all-weather vestibule cabs.

N3b

3891-3940 MLW 51538-51562, 51628-51652 1912

N3c

3941-3950 MLW 52687-52696 1913

3951-3960 Canada Foundry 993-1002 1913

The AE&RJ reminded its readers that the CPR was then in the midst of a substantial standardization drive as well a full-on adoption of the superheater in almost all of its new locomotives. As part of this policy, the CPR brought out this new version of a 2-8-0 that used "a large number of the former standard parts ...[it was], in the main, an entirely new arrangement ...a normally conservative design arranged in many particulars to suit the special circumstances under which it is to be operated."

An obvious difference could be seen in the taller drivers. Because the superheater installation reflected 1909 practice, its ratio was quite small compared to later preferences. AE&RJ noted the "exceptionally novel and interesting design of ash pan" of the "self-cleaning type." The cylinder design, the journal added, sought to shave as much weight off the system as possible. The 12" (305 mm) piston valves lay inside of the cylinders and in line with the steam route to the cylinder and used a stem set up such that isolated them from other stresses in the valve train.

All were converted to N2 series locomotives containing 35-element Schmidt Type A superheaters and slightly less cylinder volume beginning in 1923; see Locobase 4525.

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Class SD/L1a (Locobase 13302)

Data from "Consolidation Engine, Canadian Pacific Railway", Railroad Gazette, Volume 19 (6 May 1887), p. 299 and longer version at Engineering, Volume 44 (18 November 1887), pp. 523-525. See also J Davis Barnett, "Work Shops, Their Design and Construction," Paper 29 , Transactions of the Canadian Society of Civil Engineers, Volumes 3 (14 March 1889), p. 181. Works numbers were 1048 in September 1886, 1049-1050 in December, 1051 in January 1887, and 1063-1062

RG notes that this was the first 2-8-0 to be built in Canada. It was designed by FRF Brown, Mechanical Superintendent, and built at the CP's Montreal shops. Its firebox sat above the driving axles and thus gained about 8 inches (203 mm) in width over typical narrow fireboxes of the time.

Engineering's review notes that they were designed for "...working heavy freight service in summer, and passenger trains in emergencies during severe winter weather, when this service is somewhat difficult to operate. During a heavy winter, and on certain sections, the snow diminishes the adhesion and obstructs progress to such an extent that the ordinary design of engine, i.e., four wheels coupled with a four-wheel truck or bogie in front, becomes inadequate for the service required."

Brown wasn't above preening a bit, noting with satisfaction in a commentary on workshop management how quickly he turned out this class: "To show what can be done in well organized shops, a couple of instances may be given. In June, 1886, an order was given to the Canadian Pacific Railway shops, Montreal, to build some Consolidation engines, which were an entirely new class; a complete set of working drawings had to be made, all quantities got out, materials imported and otherwise prepared, and the first engine was on the road exactly 90 days after receipt of the order."

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Class SE2/L4a (Locobase 3153)

Data from Charles McShane, The Locomotive Up to Date (New York: Griffin & Winters, 1899), p. 502. Works numbers were 2696-2697 in April 1898, 2698-2701 in May, 2702-2707 in June, and 2708-2710 in July.

The data contain at least one odd feature: the short stroke for a 2-8-0 in particular or a compound in general. Also, this engine was relatively small and light for a compound 2-8-0 - the smallest of that particular combination in Locobase.

The entire class had their leading trucks deleted in June-September 1911 and, as 0-8-0s, placed in switching service.

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Class SE3/M1a, 1c, 1e (Locobase 15774)

Data from CP 1911-24 Locomotive Diagrams supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange. CPR produced the first 18 from September 1898 to October 1899. Richmond's works numbers 2794-2805 were delivered in February and March 1899. Canadian Locomotive Company works numbers 464-469, 479-484, and 498-499

The CPR bought almost four dozen of these Richmond compounds in one year, supplying 18 of their own, 12 from Richmond, and 13 from the CLC. Before very long, the entire class was converted to simple-expansion, at which point their specifications were identical to the two simple-expansion M1b.

Still later, some were converted to 0-8-0 switchers and the others were superheated. For the latter, see Locobase 15776.

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Class SE4/M2a, b, c, d (Locobase 14157)

Data from "Richmond Locomotive for the Canadian Pacific," The Daily Railway Age, Vol 14 (22 June 1900), pp. 27-28, supplemented by CP 1911 - 24 Locomotive Diagrams supplied in August 1913 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were

Sub-class Builder Works Road Month Year

M2a/b CPR 1313-1322 1148-1157 October 1900-March 1901

M2c Richmond 2977-2988 1136-1147 June 1900

M2d Canadian Locomotive 486-495 1126-1135 May-June 1900

The CLC and Richmond kicked off production of this set of "Pittsburgh" cross-compounds that rolled onto the CP's rails at the turn into the 20th Century. (Pittsburgh refers to the particular design of the intercepting valve first produced at the PLW.) All had Belpaire fireboxes and identical cylinder volume.

Renumbered in 1906, the class was superheated in 1912; see Locobase 15563.

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Class SE4/M2e, f (Locobase 15664)

Data from CP 1911-24 Locomotive Diagrams supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange. Canadian Locomotive Works works numbers were 553-556 (road 1093-1096) in 1901, 569-572 (1083-1086) in 1902, 573-576, 580-581 (1087-1092) in 1903. Canadian Foundry works numbers were 830-839 (road numbers 1496-1505)in 1904.

These were essentially repeats of the 1900 "Pittsburgh" cross-compounds (Locobase 14157) with a larger firebox. Like those engines, these were soon simpled, then superheated; see Locobase 15665.

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Class SE5/M3a, M3b (Locobase 4083)

Data from "Schenectady Compound Consolidation Freight Locomotive--Canadian Pacific Railway", Railroad Gazette, Vol 33, No 48 (29 November 1901), p. 824. See also George H Drury, Guide to North American Steam Locomotives, Revised Edition (Waukesha, WI: Kalmbach Books, 2015), p. 15 and William Withuhn, American Steam Locomotives: Design and Development: 1880-1960 (Bloomington, IN: Indiana University Press and Pflugerville, TX: Railway & Locomotive Historical Society, 2019), p. 100.Works numbers were 25092-25099 in November 1901; 26107-26118, in June 1902, 25802-25813 and 26422-26431 in July.

Embodying the policy of procuring cross-compound locomotives, this class had a relatively shallow firebox with less firebox heating surface area. They didn't remain cross-compounds for long for two related reasons. One was that the low-pressure cylinder diameter could not grow much greater without causing clearance and back-pressure problems. And that meant the 2-8-0 arrangement's tractive effort would be limited. So the CPR's shops replaced the cross-compound cylinders as shown in Locobase 15579.

This entry is as good as most to offer a more general explanation of the North American tendency to discard compounding. In addition to a conservative attitude toward innovation in early 20th Century US railroads and significant maintenance demands including working under the boiler and between the frames, and the simpler, yet very effective innovation of superheating, both WilliamWithuhn and George Drury gave two fundamental reasons for the rapid abandonment of compounding in North America.

Each defect is related to the very element in compounding that was the heart of its appeal. Reusing exhaust steam that otherwise would be released to the atmosphere, the larger cylinder could use the less-energetic byproduct to push against the larger diameter cylinder. Theoretically, a properly design low-pressure cylinder would generate the same power as its high-pressure counterpart.

For various reasons, the reuse of exhausted steam didn't always provide commensurate power. And its use compromised several features of a locomotive's standard steam circuit. First, venting the exhausted steam into the larger volume of the low-pressure cylinder encountered Charles' Law, which predicts that gas (or actually fluid) temperature will drop. In the saturated-steam era, this meant that more of the entrained water droplets would condense. Temperature dropped further as a consequence as well as water droplets condensed on the cylinder walls, adulterating lubrication and increasing friction.

Second, exhaust from a low-pressure cylinder contained less energy and moved at a lower velocity. Achieving a strong enough draft over a typical grate required a small-diameter nozzle, which created considerable back pressure in the LP, which meant expending much of the extra energy to overcome the resistance.

Other countries (France being a leading example) continued to develop compounds and operated throughout the steam era. Several designs adopted a reheater chamber that corralled the high-pressure exhaust and circulated it through heated tubes before admitting it to the low-pressure cylinder. Many continental locomotives combined compounding with superheating , which directly addressed the condensation problem by eliminating suspended water droplets from much higher-temperature steam.

The class was later superheated as shown in Locobase 15780

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Class SG/L1b (Locobase 15767)

Data from CP 1911-24 supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 1062 (406) in August 1887 and 1063 (405) in January 1888.

Following immediately the quartet of Consolidations that were the first to be built in Canada (Locobase 13302), this pair adopted a more conventional bore-stroke ratio and saw a slight drop in heating surface area.

3104 (ex-1063) left the roster in July 1920. The CP sold the 3122 in May 1927 to the Manitoba & Saskatchewan Coal Co of Bienfait, Saskatchewan.