Japanese Government Railways class C11
The C11 was a 2-6-4T tank locomotive designed by Hideo Shiima for service on secondary lines. It was closely based on the C10, but had a reduced weight thanks to the increased use of welding. Production started in 1932 at several companies and by 1947, a total of 381 had been completed. The first batches had a boiler pressure of 14 bars, but this was raised to 15 bars from 1935. Starting with C11 141 built in 1940, the water tanks had been enlarged, leading to an increased adhesive weight. From 1943, the smoke deflectors were made from wood to save steel. The class could mainly be seen in commuter service and the first ones were withdrawn in 1960 due to the introduction of diesel railcars. But until the end of the sixties, some of the remaining locomotives were even used in express service. A total of 52 have been preserved, six of which are still in working condition.
Technical data
General
| Property | 1-140 | 141-381 |
|---|---|---|
| Built | 1932-1947 | |
| Manufacturers | Hitachi, Kisha Seizō, Kawasaki, Nippon Sharyō | |
| Wheel arrangement | 2-6-4T (Adriatic) | |
| Gauge | 1,067 mm (Cape gauge) | |
Dimensions and weights
| Property | 1-140 | 141-381 |
|---|---|---|
| Length | 12.65 m | |
| Wheelbase | 10.56 m | |
| Service mass | 65.9 t | 68.1 t |
| Adhesion mass | 37 t | 39.4 t |
| Rigid wheelbase | 4.10 m | |
| Axle load | 12.4 t | 13.2 t |
| Water capacity | 6,800 l | |
| Fuel capacity | 3 t (coal) | |
Boiler
| Property | 1-140 | 141-381 |
|---|---|---|
| Grate area | 1.6 m² | |
| Firebox surface | 10 m² | |
| Tube heating surface | 63.2 m² | |
| Evaporative heating surface | 73.2 m² | |
| Superheater surface | 29.8 m² | |
| Total heating surface | 103.0 m² | |
Power plant
| Property | 1-140 | 141-381 |
|---|---|---|
| Driver diameter | 1,520 mm | |
| Boiler pressure | 14 bar | 15 bar |
| Expansion type | simple expansion | |
| Cylinders | two, 460 x 610 mm | |
Power
| Property | 1-140 | 141-381 |
|---|---|---|
| Power source | steam | |
| Indicated power | 576 kW (783 PS) | |
| Top speed | 95 km/h | |
| Starting effort | 101.1 kN | 108.3 kN |
Calculated values
| Property | 1-140 | 141-381 |
|---|---|---|
| Factor of adhesion | 1 : 3.59 | 1 : 3.57 |
| Optimal speed | 35 km/h | 32 km/h |
| Power-to-weight ratio | 8.7 kW/t | 8.5 kW/t |
| Heating Surface Equivalent | 182.8 m² | |
| Cylinder volume/HSE | 1 : 1,109.15 | |
| Adhesive weight/Total | 1 : 1.78 | 1 : 1.73 |
| Tractive force/Heating surface | 1 : 20.49 | 1 : 21.95 |
| Grate area/Heating surface | 1 : 64.38 | |
| Firebox/Tube surface | 1 : 6.32 | |
| Total/Superheater | 1 : 2.46 | |