UP class 3900
| UP class 3900 | |
|---|---|
 No. 3985 in Westfield (Texas) 2004
|
|
| Numbering: | s. table |
| Manufacturer: | ALCO |
| Year of construction (s): | 1936-1944 |
| Retirement: | s. table |
| Axis formula : | (2'C) C'2 h4 |
| Gauge : | 1435 mm ( standard gauge ) |
| Service mass: | 257 t 284 t * |
| Friction mass: | 175 t 183 t * |
| Top speed: | 100 km / h |
| Driving wheel diameter: | 1752 mm |
| Number of cylinders: | 4th |
| Cylinder diameter: | 558 mm |
| Piston stroke: | 812 mm |
| Cylinder pressure: | 1737 kPa 1929 kPa * |
| Grate area: | 10.05 m² 12.3 m² * |
| Tubular heating surface: | 499 m² |
| Superheater area : | 151 m² |
| Tender: | 2'5 |
| Water supply: | 95 m³ |
| Fuel supply: | 28 tons of coal |
| * 3930-3969 | |
The class 3900 of the Union Pacific Railroad , and Challenger called, was a series of heavy four-cylinder - steam locomotives with simple steam expansion in joint type . The machines with the wheel arrangement (2'C) C2 'h4 (American spelling: 4-6-6-4) were intended for freight traffic.
The locomotives are a further development of the sixfold coupled rigid frame machines of class 9000 with the axle arrangement 2'F1 'h3. They are of the articulated design , the leading running bogie and the three coupling axles of the front engine are mounted in a movable frame, while the three coupling axles of the rear engine and the two-axle delta towing frame are in the main frame of the locomotive. This arrangement corresponds to the mallet type , but without the composite effect of the engine. The division of the six coupling axles into two groups promised to result in lower reciprocating masses and thus a higher possible speed and better arc travel. All wheels were disc wheels, those of the driving and coupling wheel sets of the Boxpok type . The locomotives received four identical cylinders with a diameter of 560 millimeters. The piston stroke was 810 millimeters and the boiler had an operating pressure of 1757 kPa (255 psi). The first "Challenger" was on 25 August 1936 under the company number 3900 in the railway company " Union Pacific Railroad put" in service. Six locomotives of the second delivery were equipped for use in passenger train traffic . Findings from the construction of the UP class 4000 , which represented an enlarged further development of the Challenger, flowed into the improved version built from 1942. This received cylinders with a slightly smaller diameter of just 530 millimeters, a shorter firebox and a boiler pressure increased to 1929 kPa (280 psi). In total, Union Pacific procured 105 locomotives of the series, 50 of which were in the improved version. Other railway companies also ordered locomotives with the wheel arrangement (2'C) C2 'h4, such as the Z 8 series from the Northern Pacific, which, however, differed in design from the UP machines due to different requirement profiles.
The locomotives of the third to fifth construction lots were coupled with seven-axle tenders of the Centipede (2'5) type , which held 28 tons of coal and 95 m³ of water. Many locomotives were converted to run on oil. However, some of them were converted back to coal firing.
The six locomotives for passenger train service also received smoke deflectors and a special paint finish in light gray / medium gray.
Delivered designs and use
| society | designation | number | number | Manufacturer | Construction year | Retirement | comment |
|---|---|---|---|---|---|---|---|
| UP | CSA-1 | 3900-3914 | 15th | ALCO | 1936 | 1956-1952 | umgez. to 3800-3814 |
| UP | CSA-2 | 3915-3939 | 25th | ALCO | 1937 | 1956-1961 | umgez. to 3815-3839 |
| UP | 4664-5 | 3930-3949 | 20th | ALCO | 1944 | 1952-1960 | |
| UP | 4664-3 | 3950-3969 | 20th | ALCO | 1942 | 1958-1961 | |
| UP | 4664-4 | 3975-3999 | 25th | ALCO | 1936 | 1959-1961 | 3975-3984 rev. to 3708-3717 |
Whereabouts
Two "Challenger" locomotives have been preserved: Union Pacific No. 3985 was for a long time currently the largest operational steam locomotive in the world , but lost this title to Union Pacific 4014 after its restoration in May 2019. No. 3985 does not have any However, special trips through are currently being worked up again; 3977 ( converted to oil firing in 1952 and renumbered 3710) is a memorial in a park in North Platte , Nebraska . 41 ° 8 ′ 52 " N , 100 ° 45 ′ 11" W.
