Hungarian State Railways In
Hungarian State Railways class 203
The series In consisted of 24 Atlantic express locomotives built by MÁVAG between 1906 and 1908. In contrast to the two-cylinder prototypes Il and Im built in 1901, they were four-cylinder compounds and were longer and heavier with a larger boiler. All four cylinders drove the first driving axle. Additionally, they were the first European locomotives to have a Vanderbilt tender.
In trials, one attained a speed of 142 km/h with a light train of 72 tonnes. With 406 tonnes, it could still attain 111 km/h. Due to their axle load of 16 tonnes, they could only be used on some lines. In 1911, they became series 203. 203.015 was rebuilt to a superheated simple, but remained the only one to be rebuilt. After World War I, some came to Romania and were used by the CFR.
Technical data
General
| Property | as built | rebuilt superheated simple |
|---|---|---|
| Built | 1906-1908 | |
| Manufacturers | MÁVAG | |
| Wheel arrangement | 4-4-2 (Atlantic) | |
| Gauge | 1,435 mm (Standard gauge) | |
Dimensions and weights
| Property | as built | rebuilt superheated simple |
|---|---|---|
| Length | 20.70 m | 21.00 m |
| Length loco | 12.32 m | |
| Wheelbase | 9.76 m | |
| Empty mass | 67.1 t | 66.5 t |
| Service mass | 74.4 t | 74 t |
| Adhesion mass | 31.7 t | 31.5 t |
| Total mass | 121.8 t | 130.5 t |
| Rigid wheelbase | 2.20 m | |
| Axle load | 15.9 t | |
| Water capacity | 18,000 l | |
| Fuel capacity | 8 t (coal) | |
Boiler
| Property | as built | rebuilt superheated simple |
|---|---|---|
| Grate area | 3.895 m² | |
| Firebox surface | 12.65 m² | |
| Tube heating surface | 251.35 m² | 194.7 m² |
| Evaporative heating surface | 264 m² | 207.35 m² |
| Total heating surface | 264.0 m² | 259.8 m² |
| Superheater surface | 52.46 m² | |
Power plant
| Property | as built | rebuilt superheated simple |
|---|---|---|
| Driver diameter | 2,100 mm | |
| Boiler pressure | 16 bar | |
| Expansion type | compound | simple expansion |
| Cylinders | four, HP: 360 x 660 mm and LP: 620 x 660 mm | two, 485 x 660 mm |
Power
| Property | as built | rebuilt superheated simple |
|---|---|---|
| Power source | steam | |
| Indicated power | 1,200 kW (1,632 PS) | 1,350 kW (1,835 PS) |
| Top speed | 100 km/h | 126 km/h |
| Starting effort | 82.9 kN | 100.5 kN |
| Starting effort simple | 99.4 kN | |
Calculated values
| Property | as built | rebuilt superheated simple |
|---|---|---|
| Factor of adhesion | 1 : 3.75 | 1 : 3.07 |
| Optimal speed | 89 km/h | 82 km/h |
| Power-to-weight ratio | 16.1 kW/t | 18.2 kW/t |
| Heating Surface Equivalent | 327.3 m² | 375.5 m² |
| Cylinder volume/HSE | 1 : 1,019.46 | 1 : 649.40 |
| Adhesive weight/Total | 1 : 2.35 | |
| Tractive force/Heating surface | 1 : 6.55 | 1 : 8.08 |
| Grate area/Heating surface | 1 : 67.78 | 1 : 66.70 |
| Firebox/Tube surface | 1 : 19.87 | 1 : 15.39 |
| Total/Superheater | 1 : 3.95 | |
