Detroit & Toledo Shore Line 2-8-2 "Mikado" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class 21 (Locobase 7866)

Data from D&TSL 12-1953 locomotive diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 71, pp. 54. (Thanks to Chris Hohl for his 16 September 2015 email noting the original engine & tender wheelbase and the tender capacity.) Works numbers were 58000-58002 in September 1924.

Like the Consolidations that immediately preceded them into service, this trio of Mikes were slightly altered USRA Light Mikes that soon acquired a variety of enhancements to their firebox, which resulted in a sizable amount of direct heating surface. The combustion chamber ahead of the firebox supplied 55 sq ft (5.1 sq m) and arch tubes another 27 sq ft (2.5 sq m). A single Alco (road number 24) joined them a year later; see Locobase 7867

When modified later, the firebox received two thermic syphons that contributed 79 sq ft (7.35 sq m) to direct heating surface at the cost of two arch tubes. The two remaining arch tubes added 15 sq ft (1.4 sq m) for a total firebox heating surface area of 355 sq ft (33 sq m) or over 9% of evaporative heating surface area of 3,850 sq ft (357.8 sq m). By then adhesion weight had increased by more than 4 1/2 short tons to 233,510 lb (105,918 kg) and total engine weight rose by over 6 1/2 tons to 311,440 lb (141,267 kg). Much of the weight gain may be attributable to the Elesco feed water heater

Chris Hohl pointed out that the original tender capacity was 16 tons of coal. Tender weight remained approximately the same despite the addition of three more short tons (2.7 metric tonnes) of coal. This enlargement also accounts for the engine and tender wheelbase from its original 71 ft 6 1/4 in (23.32 m) to the 75 ft 5 1/2 in shown in the specs.


Class 24 (Locobase 7867)

Data from D&TSL 12-1953 locomotive diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

A year after the three Baldwins arrived on the D & TS (Locobase 7866), Alco delivered a single 2-8-2 produced in September 1925. Over time the firebox underwent the same transformation, deleting two of four arch tubes in favor of 79 sq ft (7.35 sq ft) of thermic syphons and leaving 13 sq ft (1.2 sq m) of arch tubes.


Class 25 (Locobase 7868)

Data from D&TSL 12-1953 locomotive diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 82, pp. 173+. (Thanks to Chris Hohl for his 9 May 2015 email correcting several errors including valve gear and driver diameter.) Works numbers were 60335-60338 in January 1928.

The D&TSL added this quartet to its stud of Mikados three years after the delivery of the lone Alco (Locobase 7867). The design continued the heritage of the USRA Light Mikado on which it was originally based, but there were changes.

Boiler tubes were 20" (508 mm) shorter and direct heating surface supplemented the two arch tubes (14 sq ft/ 1.3 sq m) with 55 sq ft (5.11 sq m) from the combustion chamber and 79 sq ft (7.34 sq m) in two thermic syphons. In addition, the design used an Elesco feed water heater. Piston valve measured 14" (356 mm) in diameter.

When delivered, the tenders carried 14 tons of coal and weighed approximately 190,000 lb (86,183 kg). By the end of their careers, the class's tenders carried more coal and weighed ten tons more.


Class 30 (Locobase 7869)

Data from D&TSL 12-1953 locomotive diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Chris Hohl for his 3 April 2015 email correcting the valve gear.) Works numbers were 7652-7654 in Decemberf 1936.

Nine years after Baldwin had delivered the last of the earlier Mikados (Locobase 7868), Lima contributed three more to a slightly revised edition of the USRA Light Mikado. The boiler traded 26 small tubes for 5 more flues, which increased the superheater fraction of total heating surface area. The grate remained the same, but combined arch tube and syphon area shrank by 11 sq ft. And inevitably overall weight rose.

Specifications by Steve Llanso of Sweat House Media
Class21242530
Locobase ID7866 7867 7868 7869
RailroadDetroit & Toledo Shore Line (CNR)Detroit & Toledo Shore Line (CNR)Detroit & Toledo Shore Line (CNR)Detroit & Toledo Shore Line (CNR)
CountryUSAUSAUSAUSA
Whyte2-8-22-8-22-8-22-8-2
Number in Class3143
Road Numbers21-232425-2830-32
GaugeStdStdStdStd
Number Built3143
BuilderBaldwinAlco-BrooksBaldwinLima
Year1924192519281936
Valve GearWalschaertWalschaertBakerBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)16.75 / 5.1116.75 / 5.1116.75 / 5.1116.75 / 5.11
Engine Wheelbase (ft / m)36.08 / 1136.08 / 1136.58 / 11.1536.50 / 11.13
Ratio of driving wheelbase to overall engine wheebase 0.46 0.46 0.46 0.46
Overall Wheelbase (engine & tender) (ft / m)75.46 / 2371.37 / 21.7576.10 / 23.2078.21 / 23.84
Axle Loading (Maximum Weight per Axle) (lbs / kg)58,850 / 26,69458,800 / 26,67159,570 / 27,02160,200 / 27,306
Weight on Drivers (lbs / kg)224,000 / 101,605231,700 / 105,097233,700 / 106,005238,300 / 108,091
Engine Weight (lbs / kg)298,000 / 135,171311,400 / 141,249323,010 / 146,515324,200 / 147,055
Tender Loaded Weight (lbs / kg)184,660 / 83,760189,300 / 85,865211,240 / 86,183242,800 / 110,132
Total Engine and Tender Weight (lbs / kg)482,660 / 218,931500,700 / 227,114534,250 / 232,698567,000 / 257,187
Tender Water Capacity (gals / ML)10,000 / 37.8810,000 / 37.8812,000 / 45.4514,000 / 53.03
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)19 / 17.3019 / 17.3017 / 12.7017 / 15.50
Minimum weight of rail (calculated) (lb/yd / kg/m)93 / 46.5097 / 48.5097 / 48.5099 / 49.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)63 / 160063 / 160064 / 162663 / 1600
Boiler Pressure (psi / kPa)200 / 13.80200 / 13.80200 / 13.80200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)26" x 30" / 660x76226" x 30" / 660x76226" x 30" / 660x76226" x 30" / 660x762
Tractive Effort (lbs / kg)54,724 / 24822.4254,724 / 24822.4253,869 / 24434.6054,724 / 24822.42
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.09 4.23 4.34 4.35
Heating Ability
Firebox Area (sq ft / m2)288 / 26.76341 / 31.68354 / 32.89330 / 30.67
Grate Area (sq ft / m2)66.80 / 6.2166.90 / 6.2266.80 / 6.2166.80 / 6.21
Evaporative Heating Surface (sq ft / m2)3785 / 351.643836 / 356.373727 / 346.253550 / 329.93
Superheating Surface (sq ft / m2)918 / 85.28933 / 86.68854 / 79.34989 / 91.91
Combined Heating Surface (sq ft / m2)4703 / 436.924769 / 443.054581 / 425.594539 / 421.84
Evaporative Heating Surface/Cylinder Volume205.32208.08202.17192.57
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation13,36013,38013,36013,360
Same as above plus superheater percentage16,03216,05615,89816,299
Same as above but substitute firebox area for grate area69,12081,84084,25280,520
Power L115,36415,87715,25616,063
Power MT604.85604.28575.67594.42

Reference