Saint Louis, Iron Mountain & Southern 2-8-8-2 "Chesapeake" Locomotives in the USA

Ringaboy: Retro Railware

Modern fabrics meet classic heritage looks. Unique & comfortable retro rail logo shirts & tops for ladies & men. Featuring crew, flowy, hoodies, long sleeve, scoop, slouchy, tank, thermal & V-neck styles. Custom & bulk inquiries welcome.

Class Details by Steve Llanso of Sweat House Media

Class ML-55 (Locobase 10031)

Data from William Ernest Dalby, Steam Power (London: Longmans, Green, and Co., 1915), p. 269, supplemented by Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 40, pp. 138-149 and from "MoPac 2-8-8-2 No. 4000 "Molly" the Mallet -

The Mightiest of them All," T Greuter (http://www.trainweb.org/screamingeagle/mp4000.html). Works number was 37675

in April 1912.

A pretty large fish out of water, this single Mallet's boiler included 1,230 sq ft of feedwater heater. When 4000 arrived on the railroad, it almost immediately acquired a nickname - Molly - which reflected both the tendency of engine crews to think of their locomotives as iron women and a probable play on the usual pronunciation of Mallet ("Malley").

Molly ran on the StL & IM and the Missouri Pacific as a hump switcher until 1946. T. Greuter, writing on the Trainweb website, offered an affectionate description of Molly's career. First he tells us what she didn't do: "It is easy to imagine that such an impressive engine as Molly may have been put to use on the most powerful runs of the day, cresting the limestone rises of Kirkwood with a mile-long line of coal freight, but she didn't."

So, a grand vision, yes, but not what she did, as Greuter explains:

"The fact is Molly was a blue-collar worker, through and through. Her sheer massiveness made her ideally suited for effortlessly shuffling the high tonnage in endless strings of cars, breaking-up and building trains at Missouri Pacific's yard hump in St. Louis and Dupo, as well as tending transfer drags ... a sight that must have truely been awe inspiring to witness."

And, he notes, "Nothing else owned by the road approached her, Molly was the single one of her kind on the system."

Specifications by Steve Llanso of Sweat House Media
ClassML-55
Locobase ID10,031
RailroadSaint Louis, Iron Mountain & Southern (MP)
CountryUSA
Whyte2-8-8-2
Number in Class1
Road Numbers4000
GaugeStd
Number Built1
BuilderBaldwin
Year1912
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)15 / 4.57
Engine Wheelbase (ft / m)56.58 / 17.25
Ratio of driving wheelbase to overall engine wheebase 0.27
Overall Wheelbase (engine & tender) (ft / m)85.19 / 25.97
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)395,000 / 179,169
Engine Weight (lbs / kg)435,000 / 197,313
Tender Loaded Weight (lbs / kg)160,000 / 72,575
Total Engine and Tender Weight (lbs / kg)595,000 / 269,888
Tender Water Capacity (gals / ML)8000 / 30.30
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)14 / 12.70
Minimum weight of rail (calculated) (lb/yd / kg/m)82 / 41
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)55 / 1397
Boiler Pressure (psi / kPa)200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)26" x 32" / 660x813
Low Pressure Cylinders (dia x stroke) (in / mm)40" x 32" / 1016x813
Tractive Effort (lbs / kg)94,007 / 42640.91
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.20
Heating Ability
Firebox Area (sq ft / m2)252 / 23.41
Grate Area (sq ft / m2)84 / 7.80
Evaporative Heating Surface (sq ft / m2)4533 / 421.13
Superheating Surface (sq ft / m2)890 / 82.68
Combined Heating Surface (sq ft / m2)5423 / 503.81
Evaporative Heating Surface/Cylinder Volume230.52
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation16,800
Same as above plus superheater percentage19,488
Same as above but substitute firebox area for grate area58,464
Power L15437
Power MT242.76

Reference