Prussian S 3
The Prussian Class S 3s were saturated steam locomotives developed by Hanomag for the Prussian state railways and were built from 1893.
Design
They were a further development of the S 2 and used the same boiler. The "S" stood for Schnellzuglokomotive, or express locomotive, of which the S 3 was a large and powerful type. Because larger turntables with a 16-metre diameter were then being built, the wheelbase could be longer, which gave it better riding qualities. The locomotive had one high-pressure and one low-pressure cylinder, coupled to four driving wheels in a 4-4-0 configuration.
They were the first class of locomotives to use superheating, a process in which the steam leaving the boiler is re-heated, resulting in better efficiency.
Procurement
The railway procured a total of 1,027 locomotives of this class up to 1904, and they were stabled at almost all locomotive depots (Betriebswerk or Bw), making them the most numerous German express train locomotives. In addition, several hundred units were manufactured with smaller driving wheels - dubbed the P4 class.
