PKP series Ok55
| PKP Ok55-3 | |
|---|---|
 Ok55-3
|
|
| Number: | 1 |
| Manufacturer: | ZNTK Wrocław (Aw Breslau) |
| Year of construction (s): | 1959 |
| Axis formula : | 2'C-h2t |
| Gauge : | 1435 mm ( standard gauge ) |
| Length over buffers: | 12,863 mm |
| Total wheelbase: | 9,000 mm |
| Empty mass: | 67.7 t |
| Service mass: | 85.1 t |
| Top speed: | 100 km / h |
| Indexed performance : | 930 hp (684 kW) |
| Starting tractive effort: | 103 kN |
| Driving wheel diameter: | 1,750 mm |
| Impeller diameter: | 850 mm |
| Control type : | Heusinger |
| Number of cylinders: | 2 |
| Cylinder diameter: | 540 mm |
| Piston stroke: | 630 mm |
| Boiler overpressure: | 14 bar |
| Grate area: | 2.6 m 2 |
| Superheater area : | 45.2 m² |
| Evaporation heating surface: | 127.7 m² |
| Water supply: | 10 m³ |
| Fuel supply: | 4.0 tons of coal |
The PKP series Ok55 comprised three locomotives. It was intended for use in front of passenger trains.
In 1952, two locomotives of the PKP series Ok22 were initially equipped with the much more modern and efficient heating boiler of the USATC class S 160 (PKP Tr203). These two locomotives were initially given the designation Ok203. It was not until 1959 that they were changed to Ok55-1 and Ok55-2 and carried this number together with an Ok55-3 locomotive newly built in the Wroclaw Repair Shop (ZNTK Wrocław). Its designer, Józef Fijałkowski, hoped that it would be the primary passenger locomotive for the railways in the future. Despite many advantages, the Ok55 was not built in series. In 1970 it was redrawn in Ok22 and used from Gdansk. The last Ok22 left the service in 1978. None of the three Ok55 remained.