Chicago & Alton 2-8-2 "Mikado" Type Locomotives

Class L-2 (Locobase 1414)

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. 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 (Locobase 6626)

Locobase 1414 describes the first 20 Mikes delivered to the Alton; this entry describes the next 5. 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 5 tons.

Class L-4/Q-8 (Locobase 1415)

625 engines were built to the USRA's basic, and very

successful design in 1918-1919. These 10 engines were assigned to the Chicago & Alton and represented the zenith of freight power on the C&A. They were later redesignated Q-8 and renumbered 4385-4394.

Class L1 (Locobase 9100)

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

Locobase doesn't know if these Mikados were delivered with superheaters, but, if not, they soon received a kit. Also, their delivery boiler pressure of 170 psi was soon raised to 200 psi, as shown in the specifications.

Comparing this Brooks engine 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.

Class L1A (Locobase 9101)

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

Although delivered with a few more tubes and 2 fewer flues, this class was virtually identical to the L1 (Locobase 9100). Over time, the boilers would become identical and would be pressed to 200 psi.

Specifications
Class	L-2	L-3	L-4/Q-8	L1	L1A
Locobase ID	1414	6626	1415	9100	9101
Railroad	Chicago & Alton	Chicago & Alton	Chicago & Alton	Chicago & Alton	Chicago & Alton
Whyte	2-8-2	2-8-2	2-8-2	2-8-2	2-8-2
Road Numbers	840-859	860-869	875-884	800-809	810-829
Gauge	Std	Std	Std	Std	Std
Builder	Baldwin	Baldwin	Several	Alco-Brooks	Alco-Brooks
Year	1913	1918	1918	1910	1911
Valve Gear	Walschaert	Walschaert	Walschaert	Walschaert	Walschaert
	Locomotive Length and Weight
Driver Wheelbase	16.50'	16.50'	16.70'	16.50'	16.50'
Engine Wheelbase	35.17'	35.17'	36.10'	34.75'	34.75'
Ratio of driving wheelbase to overall engine wheebase	0.47	0.47	0.46	0.47	0.47
Overall Wheelbase (engine & tender)	64.10'	71.19'	71.38'	67.04'	67.04'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers	213200 lbs	222600 lbs	221500 lbs	212300 lbs	214500 lbs
Engine Weight	281800 lbs	285300 lbs	290800 lbs	269000 lbs	273000 lbs
Tender Light Weight	178425 lbs	182000 lbs	185500 lbs	167000 lbs	167600 lbs
Total Engine and Tender Weight	460225 lbs	467300 lbs	476300 lbs	436000 lbs	440600 lbs
Tender Water Capacity	9000 gals	9500 gals	10000 gals	8500 gals	8500 gals
Tender Fuel Capacity (oil/coal)	18 tons	18 tons	16 tons	13 tons	13.5 tons
Minimum weight per yard of rail on which locomotive could run	88.83 lb rail	92.75 lb rail	92.29 lb rail	88.46 lb rail	89.38 lb rail
	Geometry Relating to Tractive Effort
Driver Diameter	63"	63"	63"	62"	62"
Boiler Pressure	200 psi	200 psi	200 psi	200 psi	170 psi
Cylinders (dia x stroke)	20" x 28"	20" x 28"	26" x 30"	28" x 30"	28" x 30"
Tractive Effort	30222 lbs	30222 lbs	54724 lbs	64490 lbs	54817 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort)	7.05	7.37	4.05	3.29	3.91
	Heating Ability
Firebox Area	240 sq. ft	242 sq. ft	280 sq. ft	237.20 sq. ft	212 sq. ft
Grate Area	70.40 sq. ft	70.40 sq. ft	66.70 sq. ft	49.50 sq. ft	49.50 sq. ft
Evaporative Heating Surface	4220	4216	3783	3481	3551
Superheating Surface	865	912	882	745	745
Combined Heating Surface	5085	5128	4665	4226	4296
Evaporative Heating Surface/Cylinder Volume	414.49	414.10	205.21	162.81	166.09
	Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation	14080	14080	13340	9900	8415
Same as above plus superheater percentage	16475.12	16584.09	15862.16	11645.27	9874.31
Same as above but substitute firebox area for grate area	56165.19	57007.80	66587.78	55803.18	42289.95
Power L1	27237.27	28122.14	14946.59	10992.43	9297.56
Power MT	1126.60	1114.08	595.06	456.60	382.24