Class 23 (Locobase 6024)

Evidence that the Ma & Pa was serious about its freight hauling came with this class of Consolidations supplied over a decade (1902 - works #20003-20004, 1905 - 25426, and 1912 - 38697). The first two were fitted with Southern valve gear in 1915.

Locomotive data from George W. Fitch, Jr.'s compilation (Maryland and Pennsylvania Railroad Preservation and Historical Society photocopy reprint, 2004). The two for which Fitch provides retirement information -- 24 & 25 -- were out of service in May 1936 and November 1939. 23 and 26 left in March 1947.

Class 27 (Locobase 7052)

Data from M&PA 1956ca Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

The Ma and Pa ordered these two Ten-wheelers almost 4 years apart. The 27 (builder's number 29760) came on the line in December 1906 while the 28 (34945) arrived in July 1910. Both were retired in 1955, the 28 first in August and the 27 in December.

Class 41 (Locobase 6025)

Locomotive data from George W. Fitch, Jr.'s compilation (Maryland and Pennsylvania Railroad Preservation and Historical Society photocopy reprint, 2004).

The first superheated locomotives for the Ma & Pa, this pair represented a substantial step up in power. Arch tubes contributed 28.3 sq ft of the firebox heating surface and the piston valves represented a relatively large 14" in diameter. They were built consecutively (works #41504-505) in June 1914.

42 was retired first in January 1952. 41 held on for another 5 years before being scrapped in May 1957.

Locobase note: Seven years later, Railway Age profiled a batch of 11 Mexican Railway locomotives (Locobase 3236) with exactly the same specifications. The data come from very different yet equally (and solidly) reliable sources, so this may an example of selling from stock.

Class 43 (Locobase 6026)

The last new locomotive for the Ma & Pa, this Consolidation had the same tractive power as the 1914 pair, but was heavier and had a higher percentage of superheat area. Arch tubes in the firebox of the 1914 engines were replaced in 43's design by thermic syphons, which represented 50.5 sq ft of firebox heating surface. 43 also had 14"-diameter pistons. The design can be described as typical of late-period American 2-8-0s, although the syphons were relatively rare.

Locomotive data from George W. Fitch, Jr.'s compilation (Maryland and Pennsylvania Railroad Preservation and Historical Society photocopy reprint, 2004). Data from M&PA 1956ca Locomotive Diagrams, supplied in May 2005 by Allen Stanley from his extensive collection, shows that the 43 went out of service in December 1956.

Class 801 (Locobase 7751)

Data from MP 1924 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

For its time, this design was relatively big and its use of 2 1/4" firetubes unusual. But its grate and heating surface areas put it in the lower half of North American Consolidations of the era (ca mid-1880s).

Because the MoPac was describing a class that had mostly been scrapped, it's not clear how many locomotives made up the original class. Baldwin delivered 2 in 1884 and 5 in 1887. New York Locomotive Works supplied 17 in 1887.

Class 851 (Locobase 7752)

Data from MP 1924 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

For its time, this design was relatively big and its use of 2 1/4" firetubes unusual. But its grate and heating surface areas put it in the lower half of North American Consolidations of the era (ca mid-1880s).

As with other old designs, the MoPac's accounting of this class is incomplete. The diagrams show that Baldwin supplied some in 1884, but the condition of the diagram makes it difficult to make out some of the other builders. One may have been Hinkley (a batch of 10 -871-880 - in 1881). Grant added some number (the first being 890) in 1881.

Class C 22/30 183 Ls / C-57 (Locobase 6901)

Data from IGN 2 - 1923 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

These small Consolidations -- the only ones on the I & GN -- were a good package with a respectable amount of superheat. The tender's oil-fuel capacity was rated at 80 barrels (3,360 US gallons).

Baldwin delivered the first 10 (works #38037-38046) in 1912, Schenectady followed with two batches (works #54229-54237 and 54366-54374) in 1913.

The Missouri Pacific later classed these as C-57s. Ten were further refitted with a firebox that had thermic syphons. The syphons added 56 sq ft to the firebox heating surface, which now totalled 227 sq ft.

Class C-55 (Locobase 7748)

Data from MP 1924 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

The second largest class of Consolidations on the MoPac and differed from the earlier Iron Mountain 2-8-0s (Locobase 7750) in having a wide firebox with substantiall increased grate area and 10" piston valves inside the frames. See Locobase 7749 for the superheated version.

Class C-55 (Locobase 7750)

Data from MP 1924 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

Ushering the 20th Century for the MoPac were these Consolidations, which had some relatively dated features (notably the small grate in a narrow firebox as well as slide valves). Brooks supplied virtually all of the engines, delivering 15 in 1901 and 25 in 1902, leaving only the last 5 to be produced by Baldwin in 1903. As far as Locobase can tell, these were never superheated.

Class C-55 - superheated (Locobase 7749)

Data from MP 1924 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

These superheated Consolidations took the usual tack of increasing cylinder size while reducing boiler pressure, a convenient tradeoff that preserved the power but lessened the strain. Piston valve diameter increased to 11", which suggests a relatively free-steaming locomotive. Locobase isn't quite sure how the rebuilders managed it, but total heating surface actually increased 274 sq ft with the subtraction of tubes in favor of flues.

Class C-57 - 34.1 (Locobase 7766)

Data from MP 8 - 1936 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

Class C-63 (Locobase 7746)

Data from MP 1924 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

The MoPac Consolidations of this class were the definitive 2-8-0 for the railroad and represented a typical design of the arrangement in North America as well. Baldwin and Alco's works at Dunkirk (Brooks) and Schenectady delivered engines over a 5-year period. Useful for all kinds of freight duties, the class was upgraded in many ways with piston valves, Baker valve gear, mechanical stokers and cast frames in some cases. See Locobase 7747 for a typical upgrade.

Class C-63 - superheated (Locobase 7747)

Data from MP 1924 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

When the extensive class of C-63 Consolidations was upgraded, the modifications took many forms. Superheating was de riguer, the larger tubes of the original boiler permitting addition of 5 1/2" flues with no loss of overall heating surface area even as the tube length was cut by 6". Note the reduced boiler pressure, a frequent resort that reduced maintenance demands even as the superheater improved the quality of the steam and larger pistons (24") and 10" piston valves offset the loss of power. Most were fitted with Walschaert valve gear, although significant numbers used Baker or Southern gear instead.