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

Class 10 (Locobase 7335)

Data from Alt&Sou 1937 locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive collection.

These were a relatively small pair of Mikes for the mid-1920s, although when stacked against all 2-8-2s, they fell into the middle of the pack. 14" piston valves promoted free-steaming and 27 sq ft of arch tubes contributed to the direct heating surface.

Class 13 (Locobase 7336)

Data from Alt&Sou 1937 locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive collection.

Ordered a year after the earlier pair (Locobase 7335), this Mike had fewer small tubes and a slightly smaller heating surface as a result. Like the others, the firebox heating surface included 27 sq ft of arch tubes.

Class 15 (Locobase 7337)

Data from Alt&Sou 1937 locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive collection.

The A & S bought one of the last Mikes to be built for an American railroad. It was a big engine with lots of power. The firebox heating surface included 86 sq ft of thermic syphons.

Class 16 (Locobase 7338)

Data from Alt&Sou 1937 locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive collection.

A year after the A & S bought a large, powerful Mike (Locobase 7337), it went to Alco for a near-sister to the 1920s 2-8-2s it had also procured from Alco.

Class 2 (Locobase 8318)

Data from Alt&Sou 1953a locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive collection.

This small railroad's stud of Mikados included several variations on a theme. Locobase 7335 describes the first pair and 7336 takes up the third to come on the road. This entry covers the one that came still later. Although the grate area remained the same, the firebox area increased by 48 sq ft (probably from the addition of a thermic syphon or two). Tube & flue length shrank by 9 inches, which reduced superheater area.

Specifications
Class	10	13	15	16	2
Locobase ID	7335	7336	7337	7338	8318
Railroad	Alton & Southern	Alton & Southern	Alton & Southern	Alton & Southern	Alton & Southern
Whyte	2-8-2	2-8-2	2-8-2	2-8-2	2-8-2
Road Numbers	10-11	13	15	16	2
Gauge	Std	Std	Std	Std	Std
Builder	Alco	Alco	Baldwin	Alco	Alco
Year	1925	1927	1936	1937	1928
Valve Gear	Walschaert	Walschaert	Baker	Walschaert	Walschaert
	Locomotive Length and Weight
Driver Wheelbase	15'	15'	16.75'	15'	15'
Engine Wheelbase	33.46'	33.46'	37.75'	33.46'	33.42'
Ratio of driving wheelbase to overall engine wheebase	0.45	0.45	0.44	0.45	0.45
Overall Wheelbase (engine & tender)	67.12'	67.12'	78.33'	67.12'	66.17'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers	220000 lbs	218500 lbs	254610 lbs	218500 lbs	220000 lbs
Engine Weight	275000 lbs	273500 lbs	346610 lbs	278500 lbs	274500 lbs
Tender Light Weight	168000 lbs	170700 lbs	232785 lbs	174100 lbs	189000 lbs
Total Engine and Tender Weight	443000 lbs	444200 lbs	579395 lbs	452600 lbs	463500 lbs
Tender Water Capacity	8000 gals	9000 gals	12000 gals	9000 gals	9000 gals
Tender Fuel Capacity (oil/coal)	14 tons	14 tons	18 tons	14 tons	14 tons
Minimum weight per yard of rail on which locomotive could run	91.67 lb rail	91.04 lb rail	106.09 lb rail	91.04 lb rail	91.67 lb rail
	Geometry Relating to Tractive Effort
Driver Diameter	57"	55"	57"	55"	55"
Boiler Pressure	190 psi	190 psi	230 psi	190 psi	190 psi
Cylinders (dia x stroke)	25" x 30"	23" x 30"	25" x 30"	25" x 30"	25" x 30"
Tractive Effort	53125 lbs	46600 lbs	64309 lbs	55057 lbs	55057 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort)	4.14	4.69	3.96	3.97	4.00
	Heating Ability
Firebox Area	243 sq. ft	243 sq. ft	332 sq. ft	296 sq. ft	291 sq. ft
Grate Area	66.80 sq. ft	66.80 sq. ft	80.20 sq. ft	66.80 sq. ft	66.80 sq. ft
Evaporative Heating Surface	3504	3464	4757	3517	3398
Superheating Surface	902	902	1424	896	866
Combined Heating Surface	4406	4366	6181	4413	4264
Evaporative Heating Surface/Cylinder Volume	205.58	240.12	279.10	206.35	199.36
	Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation	12692	12692	18446	12692	12692
Same as above plus superheater percentage	15290.32	15314.12	22695.65	15268.94	15269.69
Same as above but substitute firebox area for grate area	55621.96	55708.56	93952.08	67658.77	66519.16
Power L1	13594.50	15449.70	24655.91	13346.40	12923.35
Power MT	544.92	623.54	853.96	538.65	518.02