Imperial-Royal State Railways class 73
Polish State Railways Tp15, Czechoslovak State Railways class 414.0, and Italian State Railway class 424
After the four class 76 freight locomotives had been put into service on the Arlberg in 1884, the class 73 shown here was introduced only one year later. The new locomotive was also a 0-8-0, but had smaller cylinders and produced around 700 hp. As the first batches were built for the Arlberg Railway, they were just called “Arlberg type”. Soon they were also built for the Galician Transversal Railway and many other lines.
Between 1885 and 1909, a total of 454 were delivered by several manufacturers. On the flat, they could haul 1,650 tonnes at 30 km/h. A speed of 15 km/h could be attained either with 580 tonnes at a one percent grade or with 220 tonnes at 2.5 percent. When faster and more powerful 2-8-0 and 0-10-0 locomotives were introduced, the class 73 was increasingly used for shunting service.
After World War I, only 44 stayed with the BBÖ. 233 locomotives, more than a half of the original production, came to Poland and became PKP Tp15. 119 became class 414.0 of the ČSD, 25 came to Italy, 17 to Romania and four to the future Yugoslavia. In 1938, the Austrian locomotives became Reichsbahn class 5557. After the war, 38 were used by the ÖBB as class 55 until 1964. The ČSD retired the last one in 1969. 414.096 was preserved and is operational again since 2019.
Technical data
General
| Property | as built | increased boiler pressure |
|---|---|---|
| Built | 1885-1909 | |
| Manufacturers | Wiener Neustadt, Floridsdorf, Krauss Linz, StEG, Č, KD | |
| Wheel arrangement | 0-8-0 (Eight-coupled) | |
| Gauge | 1,435 mm (Standard gauge) | |
Dimensions and weights
| Property | as built | increased boiler pressure |
|---|---|---|
| Length | 16.48 m | |
| Wheelbase | 3.90 m | |
| Total wheelbase | 11.64 m | |
| Empty mass | 47.5 t | |
| Service mass | 55.1 t | |
| Adhesion mass | 55.1 t | |
| Rigid wheelbase | 2.55 m | |
| Water capacity | 12,000 l | |
| Fuel capacity | 7.2 t (coal) | |
Boiler
| Property | as built | increased boiler pressure |
|---|---|---|
| Grate area | 2.25 m² | |
| Firebox surface | 11.2 m² | 11.21 m² |
| Tube heating surface | 170.8 m² | |
| Evaporative heating surface | 182 m² | |
| Total heating surface | 182.0 m² | |
Power plant
| Property | as built | increased boiler pressure |
|---|---|---|
| Driver diameter | 1,100 mm | |
| Boiler pressure | 10 bar | 11 bar |
| Expansion type | simple expansion | |
| Cylinders | two, 500 x 570 mm | |
Power
| Property | as built | increased boiler pressure |
|---|---|---|
| Power source | steam | |
| Estimated power | 525 kW (714 PS) | 550 kW (748 PS) |
| Top speed | 35 km/h | |
| Starting effort | 110.1 kN | 121.1 kN |
Calculated values
| Property | as built | increased boiler pressure |
|---|---|---|
| Factor of adhesion | 1 : 4.91 | 1 : 4.46 |
| Optimal speed | 29 km/h | 27 km/h |
| Power-to-weight ratio | 9.5 kW/t | 10.0 kW/t |
| Heating Surface Equivalent | 238.0 m² | 238.1 m² |
| Cylinder volume/HSE | 1 : 940.50 | 1 : 940.26 |
| Adhesive weight/Total | 1 : 1.00 | |
| Tractive force/Heating surface | 1 : 12.64 | 1 : 13.90 |
| Grate area/Heating surface | 1 : 80.89 | |
| Firebox/Tube surface | 1 : 15.25 | 1 : 15.24 |