Louisiana & Arkansas 2-8-2 "Mikado" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class 551 (Locobase 10266)

Data from 1942 L&A diagram book supplied by Allen Stanley in March 2004. See also DeGolyer, Vol 59, pp. 434+, Vol 71, pp. 91+, and Vol 77, pp. 784+. Works numbers from Baldwin were 56912-56913 in August 1923, 58184-58185 in January 1925, and 59758-59759 in January 1927.

These Mikados had 12" (305 mm) diameter piston valves.

Rail weight was 75 lb/yard (37.5 kg/metre), grades sloped gently up 1%, and radii of 461 feet (140.5 metres).

All saw out steam on the L&A. 553-554 were scrapped in March 1952 while the others were broken up in July 1953.


Class M-22 (Locobase 1358)

Data from 1942 L&A diagram book supplied by Allen Stanley in March 2004 from his extensive Rail Data Exchange collection. (Thanks to Sam Dickenson for his 16 July 2017 email giving the information about the second career for three of the locomotives that is repeated below). Works numbers were 7641-7645 in August 1936.

This particular page was almost illegible, unfortunately, and most figures were difficult to read. It is possible to make out that of the firebox heating surface, 66 sq ft (6.15 sq m) was supplied by two thermic syphons. Works numbers were 7641-7645 in August 1936.

The indefatigable Stanley later (February 2006) unearthed another diagram book that had slightly more legible numbers, which allowed Locobase to estimate most of the missing numbers. As it happens, the L&A, like some other railroads, did not record the superheater area separately. Locobase's estimate for the area is based on five other Mikados with identical numbers of flues of nearly identical lengths, properly interpolated.

Note the hefty booster engine - 16,500 lb (7,484 kg) of tractive effort is among the highest Locobase has recorded. Few North American Mikes had cylinders as small as 23" in diameter.

Sam Dickenson reported to Locobase:

"Engines 562, 563 and 565 were sold to Paulson Spence in January of 1952 for the price of $5,800.00 a piece (in comparison to their construction price of $60,810.26 a piece) and were used on his 100% steam-powered Louisiana Eastern Railroad [as road numbers 11-13]. These were the newest locomotives to ever operate on the LERR and did so until Spence's death in 1961.

565 was scrapped in October of the following year with 562 and 563 following it the next month."

Engine 561 was scrapped at Minden in January 1952 and 564 was dismantled at Pittsburgh in October 1953.

Principal Dimensions by Steve Llanso of Middle Run Media
Class551M-22
Locobase ID10266 1358
RailroadLouisiana & ArkansasLouisiana & Arkansas
CountryUSAUSA
Whyte2-8-22-8-2
Number in Class65
Road Numbers551-556561-565
GaugeStdStd
Number Built65
BuilderBaldwinLima
Year19231936
Valve GearWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)16 / 4.8817.25 / 5.26
Engine Wheelbase (ft / m)35.33 / 10.7736.92 / 11.25
Ratio of driving wheelbase to overall engine wheelbase 0.45 0.47
Overall Wheelbase (engine & tender) (ft / m)70.83 / 21.59
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)184,000 / 83,461208,000 / 94,347
Engine Weight (lbs / kg)259,000 / 117,481282,000 / 127,913
Tender Loaded Weight (lbs / kg)220,000 / 99,790220,000 / 99,790
Total Engine and Tender Weight (lbs / kg)479,000 / 217,271502,000 / 227,703
Tender Water Capacity (gals / ML)8000 / 30.309500 / 35.98
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)3806 / 14,4064000 / 15,140
Minimum weight of rail (calculated) (lb/yd / kg/m)77 / 38.5087 / 43.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)57 / 144863 / 1600
Boiler Pressure (psi / kPa)200 / 1380240 / 1650
High Pressure Cylinders (dia x stroke) (in / mm)24" x 28" / 610x71123" x 32" / 584x813
Tractive Effort (lbs / kg)48,101 / 21818.2754,814 / 24863.24
Booster (lbs)10,80016,500
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.83 3.79
Heating Ability
Tubes (number - dia) (in / mm)221 - 2" / 51234 - 2" / 51
Flues (number - dia) (in / mm)32 - 5.375" / 13745 - 5.375" / 137
Flue/Tube length (ft / m)20.50 / 6.2520 / 6.10
Firebox Area (sq ft / m2)210 / 19.51278 / 25.83
Grate Area (sq ft / m2)57.20 / 5.3260.10 / 5.59
Evaporative Heating Surface (sq ft / m2)3491 / 324.443971 / 369.05
Superheating Surface (sq ft / m2)782 / 72.681016 / 94.42
Combined Heating Surface (sq ft / m2)4273 / 397.124987 / 463.47
Evaporative Heating Surface/Cylinder Volume238.13258.02
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation11,44014,424
Same as above plus superheater percentage13,49917,309
Same as above but substitute firebox area for grate area49,56080,064
Power L115,00723,751
Power MT719.231006.96

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