Atlantic Coast Line 2-8-2 "Mikado" Locomotives in the USA

The Atlantic Coast Line Railroad operated extensive trackage in the states of Virginia, North Carolina, South Carolina, Georgia, Alabama and Florida. Its main line ran from a connection with the Richmond Fredeericksburg and Potomac, at Richmond, Virginia southward along the Atlantic Coast to Jacksonville, Florida where it connected to the Florida East Coast Railway. New York to Miami trains traveled on the Pennsylvania to Washington, the RF&P to Richmond, either the ACL or Seaboard Air Line Railway to Jacksonville, and the FEC to Miami.

The ACL also had lines from Jacksonville to Florida inland and west coast cities of St. Petersburg, Tampa, Orlando and Sarasota. In the 30's and 40's Chicago trains headed to Florida on the C&EI, Illinois Central and Pennsylvania Railroads used the ACL for portions of their trips. After several more mergers and consolidations, the former ACL is now part of CSX Transportation, also headquartered in Jacksonville, FL.

The Atlantic Coast Line received its first "Mikado" type locomotives from the Baldwin Locomotive Works in 1911. That year Baldwin with the delivery twenty 2-8-2 locomotives, which were designated as Class M and assigned road numbers 800 through 819. They had 51 ½" diameter drivers, 22" x 30" cylinders, a 185 psi boiler pressure, they exerted 40,400 pounds of tractive effort and each weighed 233,450 pounds.

In1918 and 1919, ten Baldwin-built 2-8-2 were added to the roster. These "Mikados" were designated as Class M-2 and were given road numbers 820 through 829. In 1923, the ACL bought seven more of the Class M-2 locomotives from Baldwin and assigned them road numbers 830 through 836. These locomotives were only average size "Mikado" but they had a large boiler and at 73 square feet the large grate area was rather large. The combustion chamber contributed 86 sq ft of direct heating surface to the 35 sq ft of arch tubes and the 231 sq ft of the firebox itself. The evaporative heating surface was 3,306 square feet and with the superheater the combined heating surface was 4,048 square feet. The drivers were 64" diameter and with 27" x 30" cylinders and a 200 psi boiler pressure, they exerted 58,000 pounds of tractive effort. Each of the locomotives weighed 280,700 pounds.

The ACL took control of the Atlanta, Birmingham & Coast Railroad in 1926 and merged it into its company in 1945. With the AB&C came seventeen more 2-8-2s.

There are no surviving ACL 2-8-2 "Mikado" type locomotives.


Roster by Richard Duley

ClassQty.Road NumbersFrom Other RRYear AcquiredYear BuiltBuilderNotes
M20 800-8191911Baldwin1
M-210820-8261918Baldwin2
M-2 3827-8291919Baldwin3
M-2 7830-8361923Baldwin4
AK-1 47202, 7208, 7209,7213AB&C19461912-1915Baldwin5
AK-2117225-7235AB&C19461912-1915ALCO6
AK-3 27301-7302AB&C19461910Baldwin7
Notes:
  1. Numbers 812 and 818 sold to the Charleston &Western Carolina Railway in 1923 and became numbers 812 and 818. Number 812 scrapped in 1951. Number 818 scrapped in 1952. All the others scrapped between 1950 and 1952.
  2. Numbers 820-826 scrapped in 1952.
  3. Numbers 827-829 scrapped in 1952
  4. Numbers 831, 833 and 835 sold to the C&WC in 1949 and became numbers 855-857. Numbers 855-857 scrapped in 1952. ACL numbers 830, 832 and 834 scrapped in 1952.
  5. Ex AB&C Number 205, 208, 209 and 213. All scrapped between 1946 and 1951.
  6. Ex AB&C Number 225-235. Numbers 7225-7235 scrapped between 1947 and 1952.
  7. Ex AB&C Number 301 and 302. Number 7301 scrapped in 1946. Number 7302 scrapped in 1947.

Class Details by Steve Llanso of Sweat House Media

Class M (Locobase 13788)

Data from DeGolyer, Volume 38, p. 110. Works numbers were: 36862-36865, 36873-36876, 36889-36892, 36956-36959, 36963-36966 - all in September 1911.

The first of a small holding of Mikados on the ACL, these came relatively early in the type's history. As such, they had the low drivers, saturated boiler, and small grate that signified 2-8-2s that had been derived from earlier Consolidation designs. Also, the 8" (203 mm) piston valves seem positively puny.

Still, the ACL found uses for the class, all but two of which remained in service on the line for decades.

All were superheated; see Locobase 7668.


Class M-2 (Locobase 16238)

Data from DeGolyer, Volume 59, pp. 56+ and "Mikado Type Locomotives for the Atlantic Coast Line Railroad," Railway and Locomotive Engineers, Volume 32 (May 1919), p. 132. Works numbers were 49352, 49402 in July 1918[ 49665-49666 in August; 50129, 50361 in October; 50877 in December; 51048-51049, 51171 in January 1919. A later batch included works numbers 57370-57372 in October 1923, 57434-57437 in November.

NB: Heating surface areas come from corrections inked to the Baldwin document as changes to the original specifications.

In addition to adding superheat, Baldwin updated the original M design (Locobase 13788) with more cylinder volume, bigger firebox with combustion, and taller drivers. While still relatively light (and operating on 85 lb/yard [42.5 kg/metre] rail), the M-2s fell comfortably into the mainstream Mikado pool. Their operating environment included a shallow ruling grade of 0.6% and gentle curves of 3 degrees or less.

Firebox heating surface was now ample with the combustion chamber contributing 84 sq ft (7.8 sq m) and the five arch tubes 35 sq ft (3.25 sq m) to the basic firebox's 239 sq ft (22 sq m). Locobase cannot pin down the role of "combustion tubes" exactly, but the specs say that the twelve tubes (six to "each side of fire box below brick arch" measured 2" (50.8 mm) outside diameter. The "flues" also had a "1 1/2 [inch] Street ell driven in end point forward."

Considerable tinkering with the front end design led to the reduction in heating surfaces noted above. The cylinders were to be redesigned to have a choke in the exhaust passage as low down in the vertical passage as practicable"' it measured 2 1/8" x 10 1/2", "tapering from that size to 8 1/2" diameter at base of exhaust stand." The exhaust had a Goodfellow's patent tip 3" [76 mm]high and "of area equivalent to 6" [152 mm] diameter." Locobase supposes this measure increased the draft. (The later batch reverted to a standard Baldwin design for the tip.)

At the same time, the distance from the center of the smoke stack to the front tube sheet increased from 36" to 40", which necessitating shortening each of the boiler tubes by four inches. The specs noted "This will necessitate redesigning the steam pipes" but would "permit a better aarrangement of deflecting plate and cleaning pipe."

Piston valve diameters of 12" (305 mm) were a bit small.

The tender's water tank was no longer than the earlier designs, but was 12" deeper and 3" wider and thus more capacious. The 1923 locomotives used an even bigger tender that held 10,000 US gallons of water and 16 tons of coat. It also came with a Locomotive Stoker Company Type D coal pusher. Loaded weight did not change.

Most of the class headed directly to the scrap yard when they left service in the early 1950s.

831, 833, and 835 went to the Charleston & Western Carolina in 1949 as their 856, 855, and 857, respectively. They must have been pretty worn as they were scrapped in March 1952 like the ACL engines. 827 and 834 kept their ACL road numbers when they were sold to the Winston Salem Southbound in October 1950 and March 1952.


Class M-2 (Locobase 7667)

Data from ACL 12 - 1954 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 68, pp. 255+. Works numbers were

1918

July 49352, 49402; August 49665-49666; October 50129, 50361; December 50877

1919

January 51048-51049, 51171

1923

October 57370-57372; November 57434-57437

The design was of average size and power for its time and represented a substantial increase in power at speed over the M class (Locobase 13788) that had brought the Mikado arrangement to the ACL. The boiler wasn't much bigger, but the grate was substantially ...well ...greater in size. Also, the piston valves diameter increased by 50% to 12" (305 mm) still not comparable to many other Mikados). In addition, cutting down the tube length by 3 1/2 feet (1,067 mm) made room for a combustion chamber that added 84 sq ft (7.8 sq m) of direct heating surface to the 35 sq ft (3.25 sq m) in five arch tubes and the 231 sq ft (21.45 sq m) of the firebox itself. Fitted with Ragonnet Type B power reverse.

At the beginning, the locomotives were used in perishable-freight service at relatively high speeds. Drury (1993) says this class later served the coal traffic on the Montgomery line until the end of steam in 1952.


Class M-S (Locobase 7668)

Data from ACL 12 - 1954 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Despite the small dimensions of these Mikados, the ACL valued them enough to superheat the class. The power dimensions didn't change at all except for an increase in boiler pressure, but the tradeoff of 145 small tubes in favor of 30 large flues for the superheater meant a substantial increase in dry steam and thus effective power.

In 1923, the ACL sold the 812 (in July) and the 818 (June) to the Charleston & Western Carolina. The others weren't scrapped until 1951-1952.

Specifications by Steve Llanso of Sweat House Media
ClassMM-2M-2M-S
Locobase ID13,788 16,238 7667 7668
RailroadAtlantic Coast Line (ACL)Atlantic Coast Line (ACL)Atlantic Coast Line (ACL)Atlantic Coast Line (ACL)
CountryUSAUSAUSAUSA
Whyte2-8-22-8-22-8-22-8-2
Number in Class20171720
Road Numbers800-819820-836820-836800-819
GaugeStdStdStdStd
Number Built201717
BuilderBaldwinBaldwinBaldwinACL
Year1911191819181920
Valve GearWalschaertWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)15.75 / 4.8016.50 / 5.0316.75 / 5.1115.75 / 4.80
Engine Wheelbase (ft / m)33.08 / 10.2135 / 10.6735 / 10.6733.08 / 10.08
Ratio of driving wheelbase to overall engine wheebase 0.48 0.47 0.48 0.48
Overall Wheelbase (engine & tender) (ft / m)67.73 / 20.6469.21 / 21.1070.70 / 21.5567.65 / 20.62
Axle Loading (Maximum Weight per Axle) (lbs / kg)58,120 / 26,36348,600 / 22,045
Weight on Drivers (lbs / kg)175,000 / 79,379223,200 / 101,242232,430 / 105,429183,600 / 83,280
Engine Weight (lbs / kg)223,000 / 101,151280,700 / 127,324295,030 / 133,824242,300 / 109,906
Tender Loaded Weight (lbs / kg)160,000 / 72,484194,500 / 88,224188,000 / 85,275159,800 / 72,484
Total Engine and Tender Weight (lbs / kg)383,000 / 173,635475,200 / 215,548483,030 / 219,099402,100 / 182,390
Tender Water Capacity (gals / ML)8000 / 30.309500 / 35.9810,000 / 37.888000 / 30.30
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)12 / 13.6012 / 10.9014 / 12.7015 / 13.60
Minimum weight of rail (calculated) (lb/yd)73939777
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)56.50 / 143563 / 160064 / 162656.50 / 1435
Boiler Pressure (psi / kPa)185 / 13.80200 / 13.80200 / 13.80200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)22" x 30" / 559x76227" x 30" / 686x76227" x 30" / 686x76222" x 30" / 559x762
Tractive Effort (lbs / kg)40,412 / 18330.6059,014 / 26768.3358,092 / 26350.1243,688 / 19816.57
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.33 3.78 4.00 4.20
Heating Ability
Firebox Area (sq ft / m2)220 / 20.44358 / 33.26352 / 32.70220 / 20.45
Grate Area (sq ft / m2)54 / 5.0273.40 / 6.8273 / 6.7854 / 5.02
Evaporative Heating Surface (sq ft / m2)3661 / 340.583253 / 302.213248 / 301.753123 / 290.24
Superheating Surface (sq ft / m2)718 / 66.70742 / 68.93737 / 68.49
Combined Heating Surface (sq ft / m2)3661 / 340.583971 / 368.913990 / 370.683860 / 358.73
Evaporative Heating Surface/Cylinder Volume277.37163.63163.38236.61
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation999014,68014,60010,800
Same as above plus superheater percentage999017,32217,37412,852
Same as above but substitute firebox area for grate area40,70084,48883,77652,360
Power L1628412,15312,54015,490
Power MT316.66480.16475.77744.00

Photos

Reference