Chicago & Alton 4-4-2 "Atlantic" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class E1 (Locobase 4096)

This entry originally used data taken from a table in Paul T Warner's article on Atlantics in the Railway & Locomotive Historical Society Bulletin #62 (1943, p 20). Data later supplemented by C&A 6 - 1918 and 12 - 1924 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection and the Baldwin Specifications in DeGolyer, Volume 25, pp. 198+. Works numbers 22335 in June 1903, 22730 in August, and 22953, 23064 in September.

Warner's smaller boiler is that of the Harriman Common Atlantic design, which Drury (1993) says was the source of this quartet's dimensions. But data from a table in July 1904 American Engineer & Railroad Journal shows a bigger engine in all respects except weights, which are actually a bit lower than the HCS. For example, the boiler was credited with 326 2 1/4" tubes and a total evaporative heating surface of 3,247 sq ft.

The 1918 C&A diagrams show 278, which undoubtedly reflects the installation of a new boiler at a later date. Locobase chose the larger boiler dimensions for the specifications when he found those figures in John M Burley's First Aid to the Disabled Locomotive Engine, Air Brake and Air Signal (State Line, Pa, 1907), 140-143.

Locobase doesn't know when the Alton reduced the number of tubes in the boiler or why. A boiler smaller than 69" in diameter crammed with 326 2 1/4" tubes might have proved a maintenance headache. When the Alton superheated this set (Locobase 9040), it installed fewer tubes of 2" diameter. The class was delivered with 12" piston valves.

The answer appears to be as follows: 551 used the HCS grate while the other three were fitted with the larger grate shown in the specs. As the engines were procured around the time that Harriman surrendered control of the C & A, Locobase wonders if the confusion lies in mistakenly attributing these locomotives to the Harriman era.

See Locobase 9040 for the superheated update of this design.

Class E1 - superheated (Locobase 9040)

Data from C&A 12-1924 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

The Alton superheated its quartet of Atlantics with the usual mixture of status quo and new technology and added an unusual wrinkle. As with most modification programs in which a superheater was installed in an existing locomotive, the biggest changes came in the boiler. In this case, the usual subtraction of tubes in favor of flues included reducing the diameter of the remaining tubes from 2 1/4" to 2". Also, the Alton trimmed the firebox's width by 6", reducing grate area to 49 1/2 sq ft, but added 29 sq ft of arch tubes to the firebox's heating surface. In other words, the shops replaced all of the boiler's innards, which is more drastic surgery than usually undertaken.

Regardless of the length and complexity of the makeover, the class was out of service by the end of 1933.

Class E2 (Locobase 9041)

Data from C&A 6-1918 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. See also DeGolyer, Volume 29, pp. 26-27. (Thanks to Chris Hohl for his 18 July 2016 email noting the original tender capacity.) Works numbers were 28265 in May 1906; and 28320-28321, 28347-28348 in June.

Whatever the design features of the first set of Alton Atlantics might have been (see Locobase 4096), the second group from the same builder had a smaller boiler with smaller tubes and a much narrower grate. The class was delivered with 12" (305 mm) piston valves.

When delivered, these engines trailed tenders with the capacities as shown. Coal capacity later rose to 14 tons (12.7 tonnes) and the loaded tenders weighed 171,250 lb (77,678 kg).

At least three were superheated; see Locobase 9042.

Class E2 - superheated (Locobase 9042)

Data from C&A 12-1924 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Compared to the nearly complete redo applied to the E-1s (see Locobase 9040), the E-2 superheating project ran along much more usual lines. The firebox remained essentially untouched (although the firebox heating surface now included 15 sq ft of arch tubes) while the boiler saw the usual substitution of 1 flue for every 6 tubes removed.

The result was still a small Atlantic and given the arrangement's relatively swift supercession in fast passenger service by 4-6-2s and their inaptitude for any other kind of hauling, the class was retired by the end of 1933.

Specifications by Steve Llanso of Sweat House Media
ClassE1E1 - superheatedE2E2 - superheated
Locobase ID4096 9040 9041 9042
RailroadChicago & Alton (C&A)Chicago & Alton (C&A)Chicago & Alton (C&A)Chicago & Alton (C&A)
Number in Class4453
Road Numbers550-553550-553554-558554, 556, 557
Number Built45
BuilderBurnham, Williams & CoC & ABurnham, Williams & CoC & A
Valve GearStephensonStephensonStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft) 7.67 7.67 7.67 7.67
Engine Wheelbase (ft)27272727
Ratio of driving wheelbase to overall engine wheebase 0.28 0.28 0.28 0.28
Overall Wheelbase (engine & tender) (ft)56.2956.2956.1758.17
Axle Loading (Maximum Weight per Axle) (lbs)48,18058,400
Weight on Drivers (lbs)103,69096,28098,000114,400
Engine Weight (lbs)183,820184,470185,000194,000
Tender Loaded Weight (lbs)171,350171,250162,000171,250
Total Engine and Tender Weight (lbs)355,170355,720347,000365,250
Tender Water Capacity (gals)6000900090009000
Tender Fuel Capacity (oil/coal) (gals/tons)14141014
Minimum weight of rail (calculated) (lb/yd)86808295
Geometry Relating to Tractive Effort
Driver Diameter (in)80808080
Boiler Pressure (psi)200200200200
High Pressure Cylinders (dia x stroke) (in)20" x 28"20" x 28"20" x 28"20" x 28"
Tractive Effort (lbs)23,80023,80023,80023,800
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.36 4.05 4.12 4.81
Heating Ability
Firebox Area (sq ft)192.50221.50193208
Grate Area (sq ft)54.2049.5033.6033.60
Evaporative Heating Surface (sq ft)3247230227002002
Superheating Surface (sq ft)507507
Combined Heating Surface (sq ft)3247280927002509
Evaporative Heating Surface/Cylinder Volume318.92226.11265.20196.64
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation10,840990067206720
Same as above plus superheater percentage10,84011,68267208064
Same as above but substitute firebox area for grate area38,50052,27438,60049,920
Power L111,02620,882959919,919
Power MT468.86956.31431.88767.72

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