The G 1 was the first locomotive built directly for the Grand Ducal Oldenburg State Railways. Despite the “G” in the designation, they were designed as a universal locomotives for all train types. Also worth mentioning is the fact that the first engine “Landwuehrden” was also the first engine manufactured by the Munich locomotive manufacturer Krauss. This locomotive took part in the world exhibition in Paris in 1867 and was awarded a gold medal there.
The locomotives had two coupled axles and no carrying axles. With a diameter of 1,500 mm, the coupled wheels were large enough to also be used in front of passenger trains. There are different statements in the literature regarding the speeds that could be achieved, ranging from 45 to 50 to 60 km/h. In order to be able to use the engines without a tender depending on the occasion, the frame was designed as a water box. Thus, if the fuel was carried in the cab, shorter distances could also be covered as a tank locomotive.
Up until around 1875, only peat was used as the fuel for all locomotives in Oldenburg in order to make the company independent of importing hard coal from outside its own country. Due to the lower calorific value of the peat, about twice the amount of fuel was required, which made it necessary to design the tender differently. As with the locomotive itself, the frame in the tender was used as a water tank in order to get more space for the peat in the body. In addition, the walls were about the same height as the cab. To protect the fuel from rain, there was a roof that had hatches for filling. The capacity of the tenders was around 3.5 to 4 cubic meters of water and 4.3 tonnes of peat. After the conversion to coal firing in the late 1870s, the tender's body was made lower. Some locomotives received completely new tenders with 10 cubic meters of water.
From around 1900, the engines were phased out, since more powerful ones were already available. The first example was taken to the German Museum in Munich with a mileage of 860,000 km due to its importance. The rest were decommissioned by 1925, so that the planned re-numbering of 19 of the 46 engines originally built as class 5170 did not occur.
