Chicago & Alton 2-8-2 "Mikado" Locomotives in the USA

Class L-2/Q-6 (Locobase 1414)

Data from C&A 6 - 1918 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 46, p. 71+. Works numbers were 39472-39477, 39495-39504 in March 1913; 39583-39586, 48225-48226 in April; 48526-48528 in May.

The 20 L-2s were based on EH Harriman's passenger-service Mikado design originally supplied to the Union Pacific. They obviously were a relatively small 2-8-2; five L-3s (Locobase 6626) were near-duplicates. Steam admission came through relatively capacious 15" (381 mm) piston valves.

Later renumbering and reclassification (after the C&A's bankruptcy in 1922 and acquisition by the B&O in 1929) resulted in a continuous numbering series for the L-2/L-3 (4360-4384) and class designations of Q-6 and Q-7.

Rebuilds in World War II resulted in a virtually new engine. To the existing boiler, the Alton attached new smokeboxes, feedwater heaters, and new cylinders. In addition, the firebox was fitted with thermic syphons.

Class L-3 / Q-7 (Locobase 6626)

Data from C&A 12 - 1924 and C&A 1 - 1930 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 56, pp. 142+. (Thanks to Chris Hohl for his 1 May 2016 email noting the incorrect value (20") for the cylinder diameter.) Works numbers were 48225-48226 in April 1918; 48526-48528 in May.

Locobase 1414 describes the first 20 Mikes delivered to the Alton; this entry describes the next five.

Although similar, there were some differences in the data: Somehow, the superheater area increased by almost 50 sq ft (although the number and length of the flues and the type of superheater element appear to have stayed the same). Also, as inevitably happened in these "repeat" orders, adhesion weight grew by almost five tons. Piston valve diameter was 15" (381 mm).

After the B & O took over the Alton in 1931, it redesignated the class as Q-7 and renumbered them. 4380 and 4383-4384 were scrapped in 1947, but 4381-4382 were sold to the Gulf, Mobile & Ohio.

Class L-4, L-4a (USRA)/Q-8 (Locobase 1415)

Data from C&A 12 - 1924 Locomotive Diagrams supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange collection.. Works numbers were (L-4) 59588-59597 in October 1918 and (L-4a) 62767-62771 in January 1921.

The United States Railroad Administration allocated 625 very successful Light Mikado locomotives in 1918-1919 (Locobase 40). These 10 engines were assigned to the Chicago & Alton and represented the zenith of freight power on the C&A. Three years after Schenectady delivered the L-4, Standard Oil of Indiana ordered five more to lease to the C&A in support of the oil company. Classed L-4a by the Alton, they were exact duplicates, although somehow the adhesion weight dropped by about two short tons.

When the Baltimore & Oho took over the C&A in 1931, the L-4 and L-4as dropped into classes Q-8 and Q-8a, respectively, and took numbers 4385-4399.

Class L1 (Locobase 9100)

Data from C&A 6-1918 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

This class was the first set of MIkados delivered to the Alton. Comparing these Brooks engines with the Alton Consolidations produced by the same builder in the same year (Locobase 9096) illustrates just how much boiler was gained by adding a trailing truck. At this point, however, the grate area didn't show a commensurate increase; in fact, the H8's grate was bigger.

An unusual feature was the Alco superheater, which mounted a superheater header on each side of the smokebox (as opposed to the usual Schmidt setup of a single header placed across the face of the tubesheet near the top). Fourteen-inch (356-mm) piston valves supplied steam to the cylinders.

Before very long, the Alton would replace the Alco superheater with the Superheater Company's Schmidt Type A apparatus, increase boiler pressure by 30 psi (2.07 bar), and reduce cylinder diameter; see Locobase 12695.

Class L1 - 26" cylinders (Locobase 16295)

Data from C&A 6-1930 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

The 30 Mikados delivered by Alco's Brooks Works to the Alton (Locobases 9100-9101) arrived with superheated boilers pressed only to 160 psi (11.03 bar) and 28" diameter cylinders. L1s used Alco superheaters while the L1as had a more standard Schmidt Type A.

By 1918, the Alton had modified all of the L1/L1a locomotives by reworking the boiler innards to the distribution of tubes and flues shown in this entry.

Class L1A (Locobase 9101)

Data from C&A 6-1918 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Alexander Sheng for this 21 July 2017 email correcting the year the class was produced.) Works numbers were 48914-48933 in August 1910.

This class was virtually identical to the L1 (Locobase 9100). They had 14" (356 mm) piston valves and fireboxes bereft of any supplementary heating surface area. Their Alco superheater elements fit in flues whose diameters were enlarged by 1/8" (3.2 mm).

As they did with the earlier L1s, the Alton would replace the Alco superheater in the L1a with the Superheater Company's Schmidt Type A apparatus, increase boiler pressure by 30 psi (2.07 bar), and reduce cylinder diameter; see Locobase 12695.