Prussian G 73
German Reichsbahn class 560, Polish State Railways Tr1, and Belgian Railway HL 73
For some lines where the axle load of the standard G 7 variants was too high, the G 73 was designed with an additional leading axle, what gave a 2-8-0 wheel arrangement. It still had the same compound cylinders as the G 72, but the additional axle allowed to use a somewhat heavier boiler, while retaining the lower axle load. Between 1893 and 1895, Hanomag built only 15 since many lines had meanwhile been upgraded for heavier axle loads, allowing to use the G 72.
In World War I, there was a new requirement for freight locomotives with a low axle load. So Maffei, Krauss and Esslingen produced a new batch of 70 which were directly delivered to the army railways. These now had a feedwater heater and a boiler pressure of 14 instead of 12 bars. After the war, 23 were used in Poland as Tr1 and 17 in Belgium as HL 73. In Germany, eleven were taken over by the Reichsbahn, five by the MFFE and four by the LBE. After World War II ended, none were still in service.
Technical data
General
| Property | 1893 variant | 1917 variant |
|---|---|---|
| Built | 1893-1894 | 1917 |
| Manufacturers | Hanomag | Maffei, Krauss, Esslingen |
| Wheel arrangement | 2-8-0 (Consolidation) | |
| Gauge | 1,435 mm (Standard gauge) | |
Dimensions and weights
| Property | 1893 variant | 1917 variant |
|---|---|---|
| Length | 16.32 m | 17.35 m |
| Wheelbase | 6.30 m | |
| Service mass | 56.2 t | 60.5 t |
| Adhesion mass | 50.5 t | 52.5 t |
| Rigid wheelbase | 4.10 m | |
| Axle load | 12.6 t | 13.1 t |
| Water capacity | 12,000 l | 16,500 l |
| Fuel capacity | 5 t (coal) | 7 t (coal) |
Boiler
| Property | 1893 variant | 1917 variant |
|---|---|---|
| Grate area | 2.31 m² | |
| Firebox surface | 10.8 m² | |
| Tube heating surface | 144 m² | |
| Evaporative heating surface | 154.8 m² | |
| Total heating surface | 154.8 m² | |
Power plant
| Property | 1893 variant | 1917 variant |
|---|---|---|
| Driver diameter | 1,250 mm | |
| Boiler pressure | 12 bar | 14 bar |
| Expansion type | compound | |
| Cylinders | two, HP: 530 x 630 mm and LP: 750 x 630 mm | |
Power
| Property | 1893 variant | 1917 variant |
|---|---|---|
| Power source | steam | |
| Estimated power | 550 kW | |
| Top speed | 45 km/h | |
| Starting effort | 96.3 kN | 112.4 kN |
| Starting effort simple | 115.6 kN | 134.8 kN |
Calculated values
| Property | 1893 variant | 1917 variant |
|---|---|---|
| Factor of adhesion | 1 : 5.14 | 1 : 4.58 |
| Optimal speed | 35 km/h | 31 km/h |
| Power-to-weight ratio | 9.8 kW/t | 9.1 kW/t |
| Heating Surface Equivalent | 208.8 m² | |
| Cylinder volume/HSE | 1 : 1,332.15 | |
| Adhesive weight/Total | 1 : 1.11 | 1 : 1.15 |
| Tractive force/Heating surface | 1 : 12.99 | 1 : 15.16 |
| Grate area/Heating surface | 1 : 67.01 | |
| Firebox/Tube surface | 1 : 13.33 | |