JNR B20 Class Steam Locomotive
This type is one of several locomotive types designed according to a number of standards in order to quickly produce locomotives for wartime transportation. From 1944 to 1947, 15 of them were manufactured at the Japan National Railways (JNR) Koriyama factory and at Tateyama Heavy Industries. Designed during wartime when supplies were scarce, the locomotive used substitute materials and simplified manufacturing methods, making it the only JNR saturated steam locomotive (The steam evaporated in the boiler is sent directly to the cylinder. In contrast, heated steam locomotives use a superheater tube to further increase the pressure of the generated steam. They were introduced after the Taisho era). It could not operate on the main line but was used for switching within the rail yard until 1972. Currently, at the Kyoto Railway Museum, there is 1 in dynamic preservation (refers to locomotives that have been preserved in a ready-to-operate state, and/or are still running today) and 1 in static preservation (refers to locomotives that are preserved in a way that does not allow them to be immediately operated, and/or that are simply on display).
Specifications of B20 Class
| Wheel arrangement | 0-4-0 | Driving Wheel Diameter(mm) | 860 |
|---|---|---|---|
| Loco. Weight in Working Order(t) | 20.3 | Maximum Axle Load(t) | 10.86 |
| Tender Weight in Working Order(t) | N/A | Boiler Pressure(kg/cm²) | 13.00 |
| Heating Surface Area(㎡) | 35.86 | Cylinder Dimensions(mm) | 300×400 |
| Grate Area(㎡) | 0.81 | Overall Length(mm) | 7,000 |
| Boiler Water Capacity (m³) | 1.4 | Total Height(mm) | 3,150 |
| Loading Capacity of Water(m³) | 2.5 | Locomotive Length(mm) | N/A |
| Fuel Capacity(t) | 0.9 | Tender Length(mm) | N/A |
| Weight on Driving Wheels(t) | 20.3 | Boiler Center Height(mm) | 2,000 |