In 1928, another five 4-8-2s were delivered. This time, they came from the Baldwin Locomotive Works and were designated as Class M-2 and assigned road numbers 905 through 909. These locomotives were very similar to the Class M-1s except for an increase in total weight. Later, the boiler pressure of these last five oil burners was raised to 225 psi, which increased the tractive effort to 57,300 pounds.
There are no surviving T&P "Mountains".
|Class||Road Numbers||Year Built||Builder|
Firebox had combustion chamber and two Nicholson Thermic Syphons of 70 sq ft total heating surface, boiler fitted with Elesco feedwater heater. The Baldwin engines of 1928 had some slight differences; see Locobase 8511.
Al1 ten 4-8-2s handled the long-haul passenger trains such as the Sunshine Special, the Texan, and the Southerner.
The first five Mountains procured for passenger service by the T & P came from Schenectady in 1926 (See Locobase 229). The current entry describes the later five that arrived three years later. Like the M-1s, the M-2s had fireboxes whose heating surface area included 119 sq ft (11.05 sq m) in the combustion chamber and two Nicholson Thermic Syphons adding 70 sq ft (6.5 sq m).
The Walschaert valve gear operated 14" (356 mm) piston valves with 8" (203 mm) travel. Unlike the M-1s, which had Elescos, the M-2 boiler was fitted with the Coffin C-80 feedwater heater. The differences between the two classes were admittedly small: a slight increase in grate area and, consequently, in firebox heating surface and a more substantial reduction in superheater area.
Al1 ten 4-8-2s handled the long-haul passenger trains such as the Sunshine Special, the Texan, and the Southerner. The T & P was an early adopter of an all-diesel motive-power roster and the last steam run of any sort came in 1951.
|Principal Dimensions by Steve Llanso of Sweat House Media|
|Railroad||Texas & Pacific (T&P)||Texas & Pacific (T&P)|
|Number in Class||5||5|
|Locomotive Length and Weight|
|Driver Wheelbase (ft / m)||20 / 6.10||20 / 6.10|
|Engine Wheelbase (ft / m)||43.25 / 13.18||43.25 / 13.18|
|Ratio of driving wheelbase to overall engine wheebase||0.46||0.46|
|Overall Wheelbase (engine & tender) (ft / m)||84 / 25.60||84 / 25.60|
|Axle Loading (Maximum Weight per Axle) (lbs / kg)||61,400 / 27,851||61,500 / 27,896|
|Weight on Drivers (lbs / kg)||245,500 / 111,357||245,600 / 111,402|
|Engine Weight (lbs / kg)||360,500 / 163,520||361,400 / 163,928|
|Tender Loaded Weight (lbs / kg)||280,100 / 127,051||291,666 / 132,298|
|Total Engine and Tender Weight (lbs / kg)||640,600 / 290,571||653,066 / 296,226|
|Tender Water Capacity (gals / ML)||14,000 / 53.03||14,000 / 53.03|
|Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)||6000 / 22.70||6000 / 22.70|
|Minimum weight of rail (calculated) (lb/yd / kg/m)||102 / 51||102 / 51|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in / mm)||73 / 1854||73 / 1854|
|Boiler Pressure (psi / kPa)||210 / 14.50||225 / 15.50|
|High Pressure Cylinders (dia x stroke) (in / mm)||27" x 30" / 686x762||27" x 30" / 686x762|
|Tractive Effort (lbs / kg)||53,477 / 24256.79||57,296 / 25989.06|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.59||4.29|
|Firebox Area (sq ft / m2)||404 / 37.55||409 / 38.01|
|Grate Area (sq ft / m2)||80.30 / 7.46||81.12 / 7.54|
|Evaporative Heating Surface (sq ft / m2)||3768 / 350.19||3774 / 350.74|
|Superheating Surface (sq ft / m2)||1110 / 103.16||1032 / 95.91|
|Combined Heating Surface (sq ft / m2)||4878 / 453.35||4806 / 446.65|
|Evaporative Heating Surface/Cylinder Volume||189.53||189.84|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||16,863||18,252|
|Same as above plus superheater percentage||20,741||22,085|
|Same as above but substitute firebox area for grate area||104,353||111,350|