The Baldwin Locomotive Works delivered thirteen Class B-1a "Mountains" in 1925. These locomotives were assigned road numbers 7008 through 7020 and were similar to the Class B-1s. Seven were designed to burn lignite and the other six were equipped to burn bituminous coal.
By 1953, all of the Class B-1s and most of the B-1a locomotives were scrapped. The last Class B-1a was scrapped in 1955.
|Class||Road Numbers||Year Built||Builder|
Lima delivered eight of these Mountains for the heaviest express service without doubleheading. Equipped with healthy amount of superheater area, 14" (356 mm) piston valves, Worthington No 4 feed water heaters, Duplex automatic stokers and fitted for lignite burning. The combustion chamber contributed 105 sq ft (9.75 sq m) and the four arch tubes 34.5 sq ft (3.2 sq m) to the direct heating surface area.
See Verne L Munger, "In My Own Words: Running in the Blizzard", Trains Magazine, Vol 74, No 1 (January 2014), pp. 58-61, in which Munger describes a grueling day as fireman on 7007on 1 January 1949 as it worked the Ravenna-Alliance (Neb) section in a mounting blizzard that brought every other train to a complete stop. The last of these retired in the mid-1950s.
Baldwin's 13 B-1As in 1925 were split into seven lignite-burners (7008-7014) and six bituminous coal consumers (2015-2020). The lignite burners had 5/16" (7.9 mm) openings in the grate. The firebox heating surface was augmented by four arch tubes aggregating 34.2 sq ft (3.2 sq m) and a combustion chamber contributing 107 sq ft. (9.95 sq m). The 14"(356 mm) piston valves were only average in size. The class also had heat-treated alloy steel running gear and a Worthington #4 feed water heater.
7017 later received roller bearings on the valve gear and three were refitted with roller bearings on the driving wheel axles. (14, 18, & 20).
The last of these retired in the mid-1950s.
|Principal Dimensions by Steve Llanso of Sweat House Media|
|Railroad||Chicago, Burlington & Quincy (CB&Q)||Chicago, Burlington & Quincy (CB&Q)|
|Number in Class||8||13|
|Locomotive Length and Weight|
|Driver Wheelbase (ft / m)||19.25 / 5.87||19.25 / 5.87|
|Engine Wheelbase (ft / m)||41.63 / 12.69||41.63 / 12.69|
|Ratio of driving wheelbase to overall engine wheebase||0.46||0.46|
|Overall Wheelbase (engine & tender) (ft / m)||81.42 / 24.82|
|Axle Loading (Maximum Weight per Axle) (lbs / kg)|
|Weight on Drivers (lbs / kg)||248,050 / 112,514||249,140 / 113,008|
|Engine Weight (lbs / kg)||381,400 / 173,000||376,440 / 170,751|
|Tender Loaded Weight (lbs / kg)||205,300 / 93,123||247,000 / 112,037|
|Total Engine and Tender Weight (lbs / kg)||586,700 / 266,123||623,440 / 282,788|
|Tender Water Capacity (gals / ML)||10,000 / 37.88||12,000 / 45.45|
|Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)||20 / 18.20||18 / 16.40|
|Minimum weight of rail (calculated) (lb/yd / kg/m)||103 / 51.50||104 / 52|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in / mm)||74 / 1880||74 / 1880|
|Boiler Pressure (psi / kPa)||210 / 14.50||210 / 14.50|
|High Pressure Cylinders (dia x stroke) (in / mm)||27" x 30" / 686x762||27" x 30" / 686x762|
|Tractive Effort (lbs / kg)||52,754 / 23928.84||52,754 / 23928.84|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.70||4.72|
|Firebox Area (sq ft / m2)||376.80 / 35.01||387 / 35.95|
|Grate Area (sq ft / m2)||78.25 / 7.27||78.25 / 7.27|
|Evaporative Heating Surface (sq ft / m2)||4356 / 404.68||4263 / 396.04|
|Superheating Surface (sq ft / m2)||1172 / 108.88||1256 / 116.69|
|Combined Heating Surface (sq ft / m2)||5528 / 513.56||5519 / 512.73|
|Evaporative Heating Surface/Cylinder Volume||219.11||214.43|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||16,433||16,433|
|Same as above plus superheater percentage||19,883||20,212|
|Same as above but substitute firebox area for grate area||95,745||99,962|