The first of the Alcos for the Katy, these had 12" diameter piston valves with 1 1/16" lap, 1/4" lead, 6" total travel. They were followed a year later with very similar engines with larger cylinders.
Following the H-1s by a year, these Katy H-2a had 14" diameter piston valves with 1 1/8" lap, 1/4" lead, 6 1/2" total travel. This resulted in a useful increase in power while the boiler and grate remained essentially unchanged.
Following the H-1s by a year, these Katy H-2a had 14" diameter piston valves with 1 1/8" lap, 1/4" lead, 6 1/2" total travel. This resulted in a useful increase in power while the boiler and grate remained essentially unchanged.
These were express Pacifics for the Katy supplied in two batches by Alco - 5 in each of 1915 & 1916. By 1941, all but two had Baker gear -- 377, 385 had Walschaert gear. As with the H-2bs, these had 14" diameter piston valves with 1 1/8" lap, 1/4" lead, 6 1/2" total travel.
Following the H-3a by a couple of years, these express Pacifics had slightly higher boiler pressure and thus more tractive effort. They were otherwise essentially identical to the H-3a. Alco delivered the first 10 in 1917. Lima followed with 10 more in 1920.
Other than deleting 5 boiler tubes from the H-3's total, these Limas were virtually identical to the earlier locomotives. Some of these Pacifics were later fitted with Boxpok drivers and slotted-steel pilot, but the basic dimensions remained the same.
| Specifications | ||||||
|---|---|---|---|---|---|---|
| Class | H-1 | H-2a | H-2b | H-3a | H-3b/3c | H-3d |
| Locobase ID | 7081 | 7080 | 7082 | 5462 | 7083 | 7084 |
| Railroad | Missouri-Kansas-Texas (MKT) | Missouri-Kansas-Texas (MKT) | Missouri-Kansas-Texas (MKT) | Missouri-Kansas-Texas (MKT) | Missouri-Kansas-Texas (MKT) | Missouri-Kansas-Texas (MKT) |
| Whyte | 4-6-2 | 4-6-2 | 4-6-2 | 4-6-2 | 4-6-2 | 4-6-2 |
| Road Numbers | 358-366 | 350-356 | 367-376 | 377-388 | 389-408 | 409-412 |
| Gauge | Std | Std | Std | Std | Std | Std |
| Builder | Alco-Schenectady | Alco-Schenectady | Alco-Schenectady | Alco-Schenectady | several | Lima |
| Year | 1910 | 1911 | 1912 | 1915 | 1917 | 1923 |
| Valve Gear | Walschaert | Walschaert | Walschaert | Baker | Walschaert | Walschaert |
| Locomotive Length and Weight | ||||||
| Driver Wheelbase | 13' | 13' | 13' | 13' | 13' | 13' |
| Engine Wheelbase | 33.25' | 33.50' | 33.50' | 34.33' | 34.33' | 35.25' |
| Ratio of driving wheelbase to overall engine wheebase | 0.39 | 0.39 | 0.39 | 0.38 | 0.38 | 0.37 |
| Overall Wheelbase (engine & tender) | 68.08' | 68.25' | 68.25' | 69.37' | 69.43' | 71.10' |
| Axle Loading (Maximum Weight per Axle) | 54800 lbs | |||||
| Weight on Drivers | 147000 lbs | 147000 lbs | 155000 lbs | 165000 lbs | 165000 lbs | 165000 lbs |
| Engine Weight | 242000 lbs | 242000 lbs | 254000 lbs | 272000 lbs | 272000 lbs | 271000 lbs |
| Tender Light Weight | 158000 lbs | 158000 lbs | 159500 lbs | 160000 lbs | 160000 lbs | 201500 lbs |
| Total Engine and Tender Weight | 400000 lbs | 400000 lbs | 413500 lbs | 432000 lbs | 432000 lbs | 472500 lbs |
| Tender Water Capacity | 8000 gals | 8000 gals | 8000 gals | 8000 gals | 8000 gals | 10000 gals |
| Tender Fuel Capacity (oil/coal) | 3760 gals | 3760 gals | 3760 gals | 12.5 tons | 4033 gals | 4033 gals |
| Minimum weight per yard of rail on which locomotive could run | 81.67 lb rail | 81.67 lb rail | 86.11 lb rail | 91.67 lb rail | 91.67 lb rail | 91.67 lb rail |
| Geometry Relating to Tractive Effort | ||||||
| Driver Diameter | 73" | 73" | 73" | 73" | 73" | 73" |
| Boiler Pressure | 210 psi | 200 psi | 200 psi | 200 psi | 210 psi | 210 psi |
| Cylinders (dia x stroke) | 22" x 28" | 24" x 28" | 24" x 28" | 25" x 28" | 25" x 28" | 25" x 28" |
| Tractive Effort | 33137 lbs | 37558 lbs | 37558 lbs | 40753 lbs | 42791 lbs | 42791 lbs |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.44 | 3.91 | 4.13 | 4.05 | 3.86 | 3.86 |
| Heating Ability | ||||||
| Firebox Area | 230 sq. ft | 200 sq. ft | 200 sq. ft | 245 sq. ft | 245 sq. ft | 245 sq. ft |
| Grate Area | 49.50 sq. ft | 49.50 sq. ft | 49.50 sq. ft | 57.50 sq. ft | 57.50 sq. ft | 57.50 sq. ft |
| Evaporative Heating Surface | 2977 | 2948 | 3280 | 3838 | 3824 | 3824 |
| Superheating Surface | 719 | 597 | 688 | 870 | 870 | 870 |
| Combined Heating Surface | 3696 | 3545 | 3968 | 4708 | 4694 | 4694 |
| Evaporative Heating Surface/Cylinder Volume | 241.66 | 201.08 | 223.73 | 241.26 | 240.38 | 240.38 |
| Computations Relating to Power Output (More Information) | ||||||
| Robert LeMassena's Power Computation | 10395 | 9900 | 9900 | 11500 | 12075 | 12075 |
| Same as above plus superheater percentage | 12417.19 | 11567.22 | 11616.53 | 13625.11 | 14313.02 | 14313.02 |
| Same as above but substitute firebox area for grate area | 57696.02 | 46736.25 | 46935.48 | 58054.80 | 60985.90 | 60985.90 |
| Power L1 | 21980.38 | 15470.61 | 17380.99 | 19721.57 | 20685.16 | 20685.16 |
| Power MT | 988.95 | 696.06 | 741.65 | 790.52 | 829.14 | 829.14 |
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