Bavarian D VII
German Reichsbahn class 9876
In addition to the D VI, six-coupled tank locomotives were also procured for steeper local railway routes. While the smaller D VI was built by both Maffei and Krauss from the start, these manufacturers supplied two different models for the higher requirements. One of them was the D V from Maffei, which, however, could not meet the requirements placed on it and was therefore only built ten times. In contrast, the D VII from Krauss was able to convince, and so both companies now delivered a total of 75 pieces at the same time up to 1885.
As with its smaller sister, vacuum brakes were installed right from the start, which were later replaced by air brakes. For use on steep stretches, it was also fitted with a Riggenbach counter-pressure brake. With the exception of one example, the Reichsbahn took over all of them and classified them as class 9876. Their decommissioning began soon after the takeover and was completed by 1935. One machine each survived in the Nuremberg and Hof depots and was used there for shunting until 1960. A previously decommissioned example, the former number 1854 or 98 7658, can now be viewed in the Localbahn Museum in Bayerisch Eisenstein.
Technical data
General
| Property | 1880 variant | 1885 variant |
|---|---|---|
| Built | 1880-1885 | 1885-1895 |
| Manufacturers | Maffei, Krauss | |
| Wheel arrangement | 0-6-0T (Six-coupled) | |
| Gauge | 1,435 mm (Standard gauge) | |
Dimensions and weights
| Property | 1880 variant | 1885 variant |
|---|---|---|
| Length | 7.55 m | 1.77 m |
| Empty mass | 18.2 t | 20.7 t |
| Service mass | 26.7 t | 28.2 t |
| Adhesion mass | 26.7 t | 28.2 t |
| Axle load | 8.9 t | 9.4 t |
| Water capacity | 3,200 l | 3,700 l |
| Fuel capacity | 0.8 t (coal) | 1 t (coal) |
Boiler
| Property | 1880 variant | 1885 variant |
|---|---|---|
| Grate area | 0.83 m² | |
| Evaporative heating surface | 50.16 m² | |
| Total heating surface | 50.2 m² | |
Power plant
| Property | 1880 variant | 1885 variant |
|---|---|---|
| Driver diameter | 1,006 mm | |
| Boiler pressure | 12 bar | |
| Expansion type | simple expansion | |
| Cylinders | two, 330 x 508 mm | |
Power
| Property | 1880 variant | 1885 variant |
|---|---|---|
| Power source | steam | |
| Indicated power | 130 kW (177 PS) | |
| Top speed | 45 km/h | |
| Starting effort | 56.1 kN | |
Calculated values
| Property | 1880 variant | 1885 variant |
|---|---|---|
| Factor of adhesion | 1 : 4.67 | 1 : 4.93 |
| Optimal speed | 14 km/h | |
| Power-to-weight ratio | 4.9 kW/t | 4.6 kW/t |
| Adhesive weight/Total | 1 : 1.00 | |
| Tractive force/Heating surface | 1 : 23.36 | |
| Grate area/Heating surface | 1 : 60.43 | |