Union Pacific classes 1820 and 1830
United States 1900 28 produced
In 1900 and 1901, Baldwin built 28 similar four-cylinder Vauclain compound Ten-wheelers for the Union Pacific. The first ten were numbered 1820 to 1829 and had drivers of 69 inches, what led to the designation T-69. The other 18, numbered 1830 to 1847, had drivers of 73 inches and were designated T-73. The cylinders of all had diameters of 15.5 and 26 inches, while the stroke was 28 inches. They were simpled between 1909 and 1913 with two cylinders of 20 inches in diameter. Later, they also received a superheater. In 1915, all were renumbered in the range between 1320 and 1347. Their retirements were between 1921 and 1932.
Technical data
General
| Property | 1820 as built | 1820 simpled | 1820 superheated |
|---|---|---|---|
| Built | 1900 | ||
| Manufacturers | Baldwin | ||
| Wheel arrangement | 4-6-0 (Ten-wheeler) | ||
| Gauge | 1,435 mm (Standard gauge) | ||
Dimensions and weights
| Property | 1820 as built | 1820 simpled | 1820 superheated |
|---|---|---|---|
| Length | 19.80 m | 19.36 m | |
| Wheelbase | 8.15 m | ||
| Total wheelbase | 16.46 m | 16.56 m | 19.80 m |
| Service mass | 83.6 t | 83.3 t | 84.2 t |
| Adhesion mass | 64.6 t | 64.8 t | 65.5 t |
| Total mass | 139.1 t | 138.8 t | 139.8 t |
| Rigid wheelbase | 4.42 m | ||
| Axle load | 23.3 t | 23.1 t | 23.3 t |
| Water capacity | 22,712 l | ||
| Fuel capacity | 9.1 t (coal) | 10.9 t (coal) | |
Boiler
| Property | 1820 as built | 1820 simpled | 1820 superheated |
|---|---|---|---|
| Grate area | 3.008 m² | ||
| Firebox surface | 17.011 m² | 17.001 m² | |
| Tube heating surface | 262.461 m² | 183.669 m² | |
| Evaporative heating surface | 279.471 m² | 200.671 m² | |
| Total heating surface | 279.5 m² | 242.5 m² | |
| Superheater surface | 41.806 m² | ||
Power plant
| Property | 1820 as built | 1820 simpled | 1820 superheated |
|---|---|---|---|
| Driver diameter | 1,753 mm | ||
| Boiler pressure | 13.8 bar | ||
| Expansion type | compound | simple expansion | |
| Cylinders | four, HP: 394 x 711 mm and LP: 660 x 711 mm | two, 508 x 711 mm | |
Power
| Property | 1820 as built | 1820 simpled | 1820 superheated |
|---|---|---|---|
| Power source | steam | ||
| Estimated power | 858 kW (1,167 PS) | 1,007 kW (1,369 PS) | |
| Starting effort | 108.8 kN | 122.7 kN | |
| Starting effort simple | 130.5 kN | ||
Calculated values
| Property | 1820 as built | 1820 simpled | 1820 superheated |
|---|---|---|---|
| Factor of adhesion | 1 : 5.83 | 1 : 5.18 | 1 : 5.24 |
| Optimal speed | 48 km/h | 43 km/h | 50 km/h |
| Power-to-weight ratio | 10.3 kW/t | 12.0 kW/t | |
| Heating Surface Equivalent | 364.5 m² | 369.3 m² | |
| Cylinder volume/HSE | 1 : 1,143.31 | 1 : 790.88 | 1 : 780.68 |
| Adhesive weight/Total | 1 : 1.29 | ||
| Tractive force/Heating surface | 1 : 8.13 | 1 : 9.17 | 1 : 10.57 |
| Grate area/Heating surface | 1 : 92.91 | 1 : 80.61 | |
| Firebox/Tube surface | 1 : 15.43 | 1 : 10.80 | |
| Total/Superheater | 1 : 4.80 | ||
